STM32_TimerInterrupt Library

Why do we need this STM32_TimerInterrupt library
- Features
- Why using ISR-based Hardware Timer Interrupt is better
- Currently supported Boards
- Important Notes about ISR
Changelog
Prerequisites
Installation
- Use Arduino Library Manager
- Manual Install
- VS Code & PlatformIO
Libraries' Patches
- 1. For application requiring 2K+ HTML page
- 2. For Ethernet library
- 3. For EthernetLarge library
- 4. For Etherne2 library
- 5. For Ethernet3 library
- 6. For UIPEthernet library
- 7. For fixing ESP32 compile error
- 8. For STM32 core F3 and F4 using UIPEthernet library
HOWTO Fix Multiple Definitions Linker Error
More useful Information about STM32 Timers
New from v1.0.0
Usage
- 1. Using only Hardware Timer directly
  - 1.1 Init Hardware Timer
  - 1.2 Set Hardware Timer Interval and attach Timer Interrupt Handler function
- 2. Using 16 ISR_based Timers from 1 Hardware Timer
  - 2.1 Init Hardware Timer and ISR-based Timer
  - 2.2 Set Hardware Timer Interval and attach Timer Interrupt Handler functions
Examples
- 1. Argument_None
- 2. ISR_16_Timers_Array
- 3. ISR_RPM_Measure
- 4. ISR_Timer_Complex
- 5. RPM_Measure
- 6. SwitchDebounce
- 7. TimerInterruptTest
- 8. TimerInterruptLEDDemo
- 9. Change_Interval.
- 10. ISR_16_Timers_Array_Complex.
Example ISR_16_Timers_Array_Complex
Debug Terminal Output Samples
- 1. ISR_Timer_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A
- 2. TimerInterruptTest on STM32F7 Nucleo-144 NUCLEO_F767ZI
- 3. Argument_None on STM32F7 Nucleo-144 NUCLEO_F767ZI
- 4. Change_Interval on STM32F7 Nucleo-144 NUCLEO_F767ZI
- 5. ISR_16_Timers_Array_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI
- 6. ISR_16_Timers_Array_Complex on STM32F1 BLUEPILL_F103C8
- 7. ISR_16_Timers_Array_Complex on STM32H7 NUCLEO_H743ZI2
- 8. ISR_16_Timers_Array_Complex on STM32L5 NUCLEO_L552ZE_Q
Debug
Troubleshooting
Issues
TO DO
DONE
Contributions and Thanks
Contributing
License
Copyright

Why do we need this STM32_TimerInterrupt library

Features

This library enables you to use Interrupt from Hardware Timers on an STM32-based board, such as STM32F/L/H/G/WB/MP1.

As Hardware Timers are rare, and very precious assets of any board, this library now enables you to use up to 16 ISR-based Timers, while consuming only 1 Hardware Timer. Timers' interval is very long (ulong millisecs).

Now with these new 16 ISR-based timers, the maximum interval is practically unlimited (limited only by unsigned long milliseconds) while the accuracy is nearly perfect compared to software timers.

The most important feature is they're ISR-based timers. Therefore, their executions are not blocked by bad-behaving functions / tasks. This important feature is absolutely necessary for mission-critical tasks.

The ISR_Timer_Complex example will demonstrate the nearly perfect accuracy compared to software timers by printing the actual elapsed millisecs of each type of timers.

Being ISR-based timers, their executions are not blocked by bad-behaving functions / tasks, such as connecting to WiFi, Internet and Blynk services. You can also have many (up to 16) timers to use.

This non-being-blocked important feature is absolutely necessary for mission-critical tasks.

You'll see blynkTimer Software is blocked while system is connecting to WiFi / Internet / Blynk, as well as by blocking task in loop(), using delay() function as an example. The elapsed time then is very unaccurate

Why using ISR-based Hardware Timer Interrupt is better

Imagine you have a system with a mission-critical function, measuring water level and control the sump pump or doing something much more important. You normally use a software timer to poll, or even place the function in loop(). But what if another function is blocking the loop() or setup().

So your function might not be executed, and the result would be disastrous.

You'd prefer to have your function called, no matter what happening with other functions (busy loop, bug, etc.).

The correct choice is to use a Hardware Timer with Interrupt to call your function.

These hardware timers, using interrupt, still work even if other functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software timers using millis() or micros(). That's necessary if you need to measure some data requiring better accuracy.

Functions using normal software timers, relying on loop() and calling millis(), won't work if the loop() or setup() is blocked by certain operation. For example, certain function is blocking while it's connecting to WiFi or some services.

The catch is your function is now part of an ISR (Interrupt Service Routine), and must be lean / mean, and follow certain rules. More to read on:

HOWTO Attach Interrupt

Currently supported Boards

STM32 boards with built-in Ethernet LAN8742A such as :

Nucleo-144 (F429ZI, F767ZI, NUCLEO_H743ZI2, NUCLEO_L552ZE_Q)
Discovery (STM32F746G-DISCOVERY)
All STM32 boards (STM32F/L/H/G/WB/MP1) with 32K+ Flash, with Built-in Ethernet

STM32F/L/H/G/WB/MP1 boards (with 32+K Flash) running W5x00 or ENC28J60 shields)

Nucleo-144
Nucleo-64
Discovery
Generic STM32F0, STM32F1, STM32F2, STM32F3, STM32F4, STM32F7 (with 64+K Flash): x8 and up
STM32L0, STM32L1, STM32L4, STM32L5
STM32G0, STM32G4
STM32H7
STM32WB
STM32MP1
LoRa boards
3-D printer boards
Generic Flight Controllers
Midatronics boards

Important Notes about ISR

Inside the attached function, delay() won’t work and the value returned by millis() will not increment. Serial data received while in the function may be lost. You should declare as volatile any variables that you modify within the attached function.
Typically global variables are used to pass data between an ISR and the main program. To make sure variables shared between an ISR and the main program are updated correctly, declare them as volatile.

Prerequisites

Arduino IDE 1.8.19+ for Arduino.
Arduino Core for STM32 v2.3.0+ for STM32F/L/H/G/WB/MP1 boards.
Blynk library 1.1.0+. to use with certain example.
For built-in LAN8742A Ethernet:

STM32Ethernet library v1.3.0+ for built-in LAN8742A Ethernet on (Nucleo-144, Discovery).
LwIP library v2.1.2+ for built-in LAN8742A Ethernet on (Nucleo-144, Discovery).

For W5x00 Ethernet:

Ethernet_Generic library v2.7.1+ for W5100, W5200 and W5500.

For ENC28J60 Ethernet:

EthernetENC library v2.0.3+ for ENC28J60. . New and Better
UIPEthernet library v2.0.12+ for ENC28J60.

To use with certain example

SimpleTimer library for ISR_16_Timers_Array example.

Installation

Use Arduino Library Manager

The best and easiest way is to use Arduino Library Manager. Search for STM32_TimerInterrupt, then select / install the latest version. You can also use this link for more detailed instructions.

Manual Install

Another way to install is to:

Navigate to STM32_TimerInterrupt page.
Download the latest release STM32_TimerInterrupt-master.zip.
Extract the zip file to STM32_TimerInterrupt-master directory
Copy whole STM32_TimerInterrupt-master folder to Arduino libraries' directory such as ~/Arduino/libraries/.

VS Code & PlatformIO

Install VS Code
Install PlatformIO
Install STM32_TimerInterrupt library by using Library Manager. Search for STM32_TimerInterrupt in Platform.io Author's Libraries
Use included platformio.ini file from examples to ensure that all dependent libraries will installed automatically. Please visit documentation for the other options and examples at Project Configuration File

Libraries' Patches

Notes: These patches are totally optional and necessary only when you use the related Ethernet library and get certain error or issues.

1. For application requiring 2K+ HTML page

If your application requires 2K+ HTML page, the current Ethernet library must be modified if you are using W5200/W5500 Ethernet shields. W5100 is not supported for 2K+ buffer. If you use boards requiring different CS/SS pin for W5x00 Ethernet shield, for example ESP32, ESP8266, nRF52, etc., you also have to modify the following libraries to be able to specify the CS/SS pin correctly.

2. For Ethernet library

To fix Ethernet library, just copy these following files into the Ethernet library directory to overwrite the old files:

3. For EthernetLarge library

To fix EthernetLarge library, just copy these following files into the EthernetLarge library directory to overwrite the old files:

4. For Ethernet2 library

To fix Ethernet2 library, just copy these following files into the Ethernet2 library directory to overwrite the old files:

To add UDP Multicast support, necessary for the UPnP_Generic library:

5. For Ethernet3 library

To fix Ethernet3 library, just copy these following files into the Ethernet3 library directory to overwrite the old files:

6. For UIPEthernet library

To be able to compile and run on nRF52 boards with ENC28J60 using UIPEthernet library, you have to copy these following files into the UIPEthernet utility directory to overwrite the old files:

7. For fixing ESP32 compile error

To fix ESP32 compile error, just copy the following file into the ESP32 cores/esp32 directory (e.g. ./arduino-1.8.12/hardware/espressif/cores/esp32) to overwrite the old file:

Server.h

8. For STM32 core F3 and F4 using UIPEthernet library

Check if you need to install the UIPEthernet patch new STM32 core F3/F4 compatibility to avoid errors #include HardwareSPI.h on some STM32 boards (Nucleo-32 F303K8, etc.)

HOWTO Fix `Multiple Definitions` Linker Error

The current library implementation, using xyz-Impl.h instead of standard xyz.cpp, possibly creates certain Multiple Definitions Linker error in certain use cases.

You can use

#include <STM32_ISR_Timer.hpp>               //https://github.com/khoih-prog/STM32_TimerInterrupt

in many files. But be sure to use the following #include <STM32_ISR_Timer.h> in just 1 .h, .cpp or .ino file, which must not be included in any other file, to avoid Multiple Definitions Linker Error

// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
#include <STM32_ISR_Timer.h>                //https://github.com/khoih-prog/STM32_TimerInterrupt

More useful Information about STM32 Timers

The Timers of STM32s are numerous, yet very sophisticated and powerful.

In general, across the STM32 microcontrollers families, the timer peripherals that have the same name also have the same features set, but there are a few exceptions.

For example, the TIM1 timer peripheral is shared across the STM32F1 Series, STM32F2 Series and STM32F4 Series, but for the specific case of STM32F30x microcontrollers family, the TIM1 timer peripheral features a bit richer features set than the TIM1 present in the other families.

The general purpose timers embedded by the STM32 microcontrollers share the same backbone structure; they differ only on the level of features embedded by a given timer peripheral.

The level of features integration for a given timer peripheral is decided based on the applications field that it targets.

The timer peripherals can be classified as: • Advanced-configuration timers like TIM1 and TIM8 among others. • General-purpose configuration timers like TIM2 and TIM3 among others • Lite-configuration timers like TIM9, TIM10, TIM12 and TIM16 among others • Basic-configuration timers like TIM6 and TIM7 among others.

For example, STM32F103C8T6 has one advance timer, while STM32F103VET6 has two advanced timers. Nucleo-144 STM32F767ZI boards have 14 Timers, TIM1-TIM14.

More information can be found at Embedded-Lab STM32 TIMERS

To be sure which Timer is available for the board you're using, check the Core Package's related files. For example, for Nucleo-144 STM32F767ZI, check these files:

~/.arduino15/packages/STM32/hardware/stm32/1.9.0/system/Drivers/CMSIS/Device/ST/STM32F7xx/Include/stm32f7xx.h
~/.arduino15/packages/STM32/hardware/stm32/1.9.0/system/Drivers/CMSIS/Device/ST/STM32F7xx/Include/stm32f767xx.h

The information will be as follows:

typedef struct
{
  __IO uint32_t CR1;         /*!< TIM control register 1,              Address offset: 0x00 */
  __IO uint32_t CR2;         /*!< TIM control register 2,              Address offset: 0x04 */
  __IO uint32_t SMCR;        /*!< TIM slave mode control register,     Address offset: 0x08 */
  __IO uint32_t DIER;        /*!< TIM DMA/interrupt enable register,   Address offset: 0x0C */
  __IO uint32_t SR;          /*!< TIM status register,                 Address offset: 0x10 */
  __IO uint32_t EGR;         /*!< TIM event generation register,       Address offset: 0x14 */
  __IO uint32_t CCMR1;       /*!< TIM capture/compare mode register 1, Address offset: 0x18 */
  __IO uint32_t CCMR2;       /*!< TIM capture/compare mode register 2, Address offset: 0x1C */
  __IO uint32_t CCER;        /*!< TIM capture/compare enable register, Address offset: 0x20 */
  __IO uint32_t CNT;         /*!< TIM counter register,                Address offset: 0x24 */
  __IO uint32_t PSC;         /*!< TIM prescaler,                       Address offset: 0x28 */
  __IO uint32_t ARR;         /*!< TIM auto-reload register,            Address offset: 0x2C */
  __IO uint32_t RCR;         /*!< TIM repetition counter register,     Address offset: 0x30 */
  __IO uint32_t CCR1;        /*!< TIM capture/compare register 1,      Address offset: 0x34 */
  __IO uint32_t CCR2;        /*!< TIM capture/compare register 2,      Address offset: 0x38 */
  __IO uint32_t CCR3;        /*!< TIM capture/compare register 3,      Address offset: 0x3C */
  __IO uint32_t CCR4;        /*!< TIM capture/compare register 4,      Address offset: 0x40 */
  __IO uint32_t BDTR;        /*!< TIM break and dead-time register,    Address offset: 0x44 */
  __IO uint32_t DCR;         /*!< TIM DMA control register,            Address offset: 0x48 */
  __IO uint32_t DMAR;        /*!< TIM DMA address for full transfer,   Address offset: 0x4C */
  __IO uint32_t OR;          /*!< TIM option register,                 Address offset: 0x50 */
  __IO uint32_t CCMR3;       /*!< TIM capture/compare mode register 3,      Address offset: 0x54 */
  __IO uint32_t CCR5;        /*!< TIM capture/compare mode register5,       Address offset: 0x58 */
  __IO uint32_t CCR6;        /*!< TIM capture/compare mode register6,       Address offset: 0x5C */
  __IO uint32_t AF1;         /*!< TIM Alternate function option register 1, Address offset: 0x60 */
  __IO uint32_t AF2;         /*!< TIM Alternate function option register 2, Address offset: 0x64 */

} TIM_TypeDef;

and

#define PERIPH_BASE            0x40000000UL /*!< Base address of : AHB/ABP Peripherals   
/*!< Peripheral memory map */
#define APB1PERIPH_BASE        PERIPH_BASE

/*!< APB1 peripherals */
#define TIM2_BASE             (APB1PERIPH_BASE + 0x0000UL)
#define TIM3_BASE             (APB1PERIPH_BASE + 0x0400UL)
#define TIM4_BASE             (APB1PERIPH_BASE + 0x0800UL)
#define TIM5_BASE             (APB1PERIPH_BASE + 0x0C00UL)
#define TIM6_BASE             (APB1PERIPH_BASE + 0x1000UL)
#define TIM7_BASE             (APB1PERIPH_BASE + 0x1400UL)
#define TIM12_BASE            (APB1PERIPH_BASE + 0x1800UL)
#define TIM13_BASE            (APB1PERIPH_BASE + 0x1C00UL)
#define TIM14_BASE            (APB1PERIPH_BASE + 0x2000UL)

/*!< APB2 peripherals */
#define TIM1_BASE             (APB2PERIPH_BASE + 0x0000UL)
#define TIM8_BASE             (APB2PERIPH_BASE + 0x0400UL)
#define TIM9_BASE             (APB2PERIPH_BASE + 0x4000UL)
#define TIM10_BASE            (APB2PERIPH_BASE + 0x4400UL)
#define TIM11_BASE            (APB2PERIPH_BASE + 0x4800UL)

...

#define TIM2                ((TIM_TypeDef *) TIM2_BASE)
#define TIM3                ((TIM_TypeDef *) TIM3_BASE)
#define TIM4                ((TIM_TypeDef *) TIM4_BASE)
#define TIM5                ((TIM_TypeDef *) TIM5_BASE)
#define TIM6                ((TIM_TypeDef *) TIM6_BASE)
#define TIM7                ((TIM_TypeDef *) TIM7_BASE)
#define TIM12               ((TIM_TypeDef *) TIM12_BASE)
#define TIM13               ((TIM_TypeDef *) TIM13_BASE)
#define TIM14               ((TIM_TypeDef *) TIM14_BASE)
...
#define TIM1                ((TIM_TypeDef *) TIM1_BASE)
#define TIM8                ((TIM_TypeDef *) TIM8_BASE)
...
#define TIM9                ((TIM_TypeDef *) TIM9_BASE)
#define TIM10               ((TIM_TypeDef *) TIM10_BASE)
#define TIM11               ((TIM_TypeDef *) TIM11_BASE)

New from v1.0.0

Now with these new 16 ISR-based timers (while consuming only 1 hardware timer), the maximum interval is practically unlimited (limited only by unsigned long milliseconds). The accuracy is nearly perfect compared to software timers. The most important feature is they're ISR-based timers Therefore, their executions are not blocked by bad-behaving functions / tasks. This important feature is absolutely necessary for mission-critical tasks.

The ISR_Timer_Complex example will demonstrate the nearly perfect accuracy compared to software timers by printing the actual elapsed millisecs of each type of timers. Being ISR-based timers, their executions are not blocked by bad-behaving functions / tasks, such as connecting to WiFi, Internet and Blynk services. You can also have many (up to 16) timers to use. This non-being-blocked important feature is absolutely necessary for mission-critical tasks. You'll see blynkTimer Software is blocked while system is connecting to WiFi / Internet / Blynk, as well as by blocking task in loop(), using delay() function as an example. The elapsed time then is very unaccurate

Usage

Before using any Timer, you have to make sure the Timer has not been used by any other purpose.

1. Using only Hardware Timer directly

1.1 Init Hardware Timer

// Init STM32 timer TIM1
STM32Timer ITimer0(TIM1);

1.2 Set Hardware Timer Interval and attach Timer Interrupt Handler function

void TimerHandler0(void)
{
  // Doing something here inside ISR
}

#define TIMER0_INTERVAL_MS        1000      // 1s = 1000ms
void setup()
{
  ....
  
  // Interval in microsecs
  if (ITimer0.attachInterruptInterval(TIMER0_INTERVAL_MS * 1000, TimerHandler0))
    Serial.println("Starting  ITimer0 OK, millis() = " + String(millis()));
  else
    Serial.println("Can't set ITimer0. Select another freq. or timer");
}

2. Using 16 ISR_based Timers from 1 Hardware Timer

2.1 Init Hardware Timer and ISR-based Timer

// Init STM32 timer TIM1
STM32Timer ITimer(TIM1);

// Init STM32_ISR_Timer
// Each STM32_ISR_Timer can service 16 different ISR-based timers
STM32_ISR_Timer ISR_Timer;

2.2 Set Hardware Timer Interval and attach Timer Interrupt Handler functions

void TimerHandler(void)
{
  ISR_Timer.run();
}

#define HW_TIMER_INTERVAL_US          100L

#define TIMER_INTERVAL_2S             2000L
#define TIMER_INTERVAL_5S             5000L
#define TIMER_INTERVAL_11S            11000L
#define TIMER_INTERVAL_101S           101000L

// In STM32, avoid doing something fancy in ISR, for example complex Serial.print with String() argument
// The pure simple Serial.prints here are just for demonstration and testing. Must be eliminate in working environment
// Or you can get this run-time error / crash
void doingSomething2s()
{
  // Doing something here inside ISR
}
  
void doingSomething5s()
{
  // Doing something here inside ISR
}

void doingSomething11s()
{
  // Doing something here inside ISR
}

void doingSomething101s()
{
  // Doing something here inside ISR
}

void setup()
{
  ....
  
  // Interval in microsecs
  if (ITimer.attachInterruptInterval(HW_TIMER_INTERVAL_US, TimerHandler))
  {
    lastMillis = millis();
    Serial.println("Starting  ITimer OK, millis() = " + String(lastMillis));
  }
  else
    Serial.println("Can't set ITimer correctly. Select another freq. or interval");

  // Just to demonstrate, don't use too many ISR Timers if not absolutely necessary
  // You can use up to 16 timer for each ISR_Timer
  ISR_Timer.setInterval(TIMER_INTERVAL_2S, doingSomething2s);
  ISR_Timer.setInterval(TIMER_INTERVAL_5S, doingSomething5s);
  ISR_Timer.setInterval(TIMER_INTERVAL_11S, doingSomething11s);
  ISR_Timer.setInterval(TIMER_INTERVAL_101S, doingSomething101s);
}

Examples:

Example ISR_16_Timers_Array_Complex

#if !( defined(STM32F0) || defined(STM32F1) || defined(STM32F2) || defined(STM32F3)  ||defined(STM32F4) || defined(STM32F7) || \
       defined(STM32L0) || defined(STM32L1) || defined(STM32L4) || defined(STM32H7)  ||defined(STM32G0) || defined(STM32G4) || \
       defined(STM32WB) || defined(STM32MP1) || defined(STM32L5) )
  #error This code is designed to run on STM32F/L/H/G/WB/MP1 platform! Please check your Tools->Board setting.
#endif

// These define's must be placed at the beginning before #include "STM32TimerInterrupt.h"
// _TIMERINTERRUPT_LOGLEVEL_ from 0 to 4
// Don't define _TIMERINTERRUPT_LOGLEVEL_ > 0. Only for special ISR debugging only. Can hang the system.
// Don't define TIMER_INTERRUPT_DEBUG > 2. Only for special ISR debugging only. Can hang the system.
#define TIMER_INTERRUPT_DEBUG         0
#define _TIMERINTERRUPT_LOGLEVEL_     3

#include "STM32TimerInterrupt.h"

// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
#include "STM32_ISR_Timer.h"

#include <SimpleTimer.h>              // https://github.com/jfturcot/SimpleTimer

#ifndef LED_BUILTIN
#define LED_BUILTIN       13
#endif

#ifndef LED_BLUE
#define LED_BLUE          2
#endif

#ifndef LED_RED
#define LED_RED           3
#endif

#define HW_TIMER_INTERVAL_US      10000L

volatile uint32_t startMillis = 0;

// Depending on the board, you can select STM32 Hardware Timer from TIM1-TIM22
// For example, F767ZI can select Timer from TIM1-TIM14
// If you select a Timer not correctly, you'll get a message from ci[ompiler
// 'TIMxx' was not declared in this scope; did you mean 'TIMyy'?

// Init STM32 timer TIM1
STM32Timer ITimer(TIM1);

// Init STM32_ISR_Timer
// Each STM32_ISR_Timer can service 16 different ISR-based timers
STM32_ISR_Timer ISR_Timer;


#define LED_TOGGLE_INTERVAL_MS        2000L

void TimerHandler()
{
  static bool toggle  = false;
  static int timeRun  = 0;

  ISR_Timer.run();

  // Toggle LED every LED_TOGGLE_INTERVAL_MS = 2000ms = 2s
  if (++timeRun == ((LED_TOGGLE_INTERVAL_MS * 1000) / HW_TIMER_INTERVAL_US) )
  {
    timeRun = 0;

    //timer interrupt toggles pin LED_BUILTIN
    digitalWrite(LED_BUILTIN, toggle);
    toggle = !toggle;
  }
}

/////////////////////////////////////////////////

#define NUMBER_ISR_TIMERS         16

typedef void (*irqCallback)  ();

/////////////////////////////////////////////////

#define USE_COMPLEX_STRUCT      true

#if USE_COMPLEX_STRUCT

typedef struct
{
  irqCallback   irqCallbackFunc;
  uint32_t      TimerInterval;
  unsigned long deltaMillis;
  unsigned long previousMillis;
} ISRTimerData;

// In NRF52, avoid doing something fancy in ISR, for example Serial.print()
// The pure simple Serial.prints here are just for demonstration and testing. Must be eliminate in working environment
// Or you can get this run-time error / crash

void doingSomething(int index);

#else

volatile unsigned long deltaMillis    [NUMBER_ISR_TIMERS] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
volatile unsigned long previousMillis [NUMBER_ISR_TIMERS] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// You can assign any interval for any timer here, in milliseconds
uint32_t TimerInterval[NUMBER_ISR_TIMERS] =
{
  5000L,  10000L,  15000L,  20000L,  25000L,  30000L,  35000L,  40000L,
  45000L, 50000L,  55000L,  60000L,  65000L,  70000L,  75000L,  80000L
};

void doingSomething(int index)
{
  unsigned long currentMillis  = millis();

  deltaMillis[index]    = currentMillis - previousMillis[index];
  previousMillis[index] = currentMillis;
}

#endif

////////////////////////////////////
// Shared
////////////////////////////////////

void doingSomething0()
{
  doingSomething(0);
}

void doingSomething1()
{
  doingSomething(1);
}

void doingSomething2()
{
  doingSomething(2);
}

void doingSomething3()
{
  doingSomething(3);
}

void doingSomething4()
{
  doingSomething(4);
}

void doingSomething5()
{
  doingSomething(5);
}

void doingSomething6()
{
  doingSomething(6);
}

void doingSomething7()
{
  doingSomething(7);
}

void doingSomething8()
{
  doingSomething(8);
}

void doingSomething9()
{
  doingSomething(9);
}

void doingSomething10()
{
  doingSomething(10);
}

void doingSomething11()
{
  doingSomething(11);
}

void doingSomething12()
{
  doingSomething(12);
}

void doingSomething13()
{
  doingSomething(13);
}

void doingSomething14()
{
  doingSomething(14);
}

void doingSomething15()
{
  doingSomething(15);
}

#if USE_COMPLEX_STRUCT

ISRTimerData curISRTimerData[NUMBER_ISR_TIMERS] =
{
  //irqCallbackFunc, TimerInterval, deltaMillis, previousMillis
  { doingSomething0,    5000L, 0, 0 },
  { doingSomething1,   10000L, 0, 0 },
  { doingSomething2,   15000L, 0, 0 },
  { doingSomething3,   20000L, 0, 0 },
  { doingSomething4,   25000L, 0, 0 },
  { doingSomething5,   30000L, 0, 0 },
  { doingSomething6,   35000L, 0, 0 },
  { doingSomething7,   40000L, 0, 0 },
  { doingSomething8,   45000L, 0, 0 },
  { doingSomething9,   50000L, 0, 0 },
  { doingSomething10,  55000L, 0, 0 },
  { doingSomething11,  60000L, 0, 0 },
  { doingSomething12,  65000L, 0, 0 },
  { doingSomething13,  70000L, 0, 0 },
  { doingSomething14,  75000L, 0, 0 },
  { doingSomething15,  80000L, 0, 0 }
};

void doingSomething(int index)
{
  unsigned long currentMillis  = millis();

  curISRTimerData[index].deltaMillis    = currentMillis - curISRTimerData[index].previousMillis;
  curISRTimerData[index].previousMillis = currentMillis;
}

#else

irqCallback irqCallbackFunc[NUMBER_ISR_TIMERS] =
{
  doingSomething0,  doingSomething1,  doingSomething2,  doingSomething3,
  doingSomething4,  doingSomething5,  doingSomething6,  doingSomething7,
  doingSomething8,  doingSomething9,  doingSomething10, doingSomething11,
  doingSomething12, doingSomething13, doingSomething14, doingSomething15
};

#endif
///////////////////////////////////////////

#define SIMPLE_TIMER_MS        2000L

// Init SimpleTimer
SimpleTimer simpleTimer;

// Here is software Timer, you can do somewhat fancy stuffs without many issues.
// But always avoid
// 1. Long delay() it just doing nothing and pain-without-gain wasting CPU power.Plan and design your code / strategy ahead
// 2. Very long "do", "while", "for" loops without predetermined exit time.
void simpleTimerDoingSomething2s()
{
  static unsigned long previousMillis = startMillis;

  unsigned long currMillis = millis();

  Serial.print(F("SimpleTimer : ")); Serial.print(SIMPLE_TIMER_MS / 1000);
  Serial.print(F(", ms : ")); Serial.print(currMillis);
  Serial.print(F(", Dms : ")); Serial.println(currMillis - previousMillis);

  for (uint16_t i = 0; i < NUMBER_ISR_TIMERS; i++)
  {
#if USE_COMPLEX_STRUCT
    Serial.print(F("Timer : ")); Serial.print(i);
    Serial.print(F(", programmed : ")); Serial.print(curISRTimerData[i].TimerInterval);
    Serial.print(F(", actual : ")); Serial.println(curISRTimerData[i].deltaMillis);
#else
    Serial.print(F("Timer : ")); Serial.print(i);
    Serial.print(F(", programmed : ")); Serial.print(TimerInterval[i]);
    Serial.print(F(", actual : ")); Serial.println(deltaMillis[i]);
#endif
  }

  previousMillis = currMillis;
}

void setup()
{
  pinMode(LED_BUILTIN, OUTPUT);

  Serial.begin(115200);
  while (!Serial);

  delay(100);

  Serial.print(F("\nStarting ISR_16_Timers_Array_Complex on ")); Serial.println(BOARD_NAME);
  Serial.println(STM32_TIMER_INTERRUPT_VERSION);
  Serial.print(F("CPU Frequency = ")); Serial.print(F_CPU / 1000000); Serial.println(F(" MHz"));

  // Interval in microsecs
  if (ITimer.attachInterruptInterval(HW_TIMER_INTERVAL_US, TimerHandler))
  {
    startMillis = millis();
    Serial.print(F("Starting ITimer OK, millis() = ")); Serial.println(startMillis);
  }
  else
    Serial.println(F("Can't set ITimer correctly. Select another freq. or interval"));

  // Just to demonstrate, don't use too many ISR Timers if not absolutely necessary
  // You can use up to 16 timer for each STM32_ISR_Timer
  for (uint16_t i = 0; i < NUMBER_ISR_TIMERS; i++)
  {
#if USE_COMPLEX_STRUCT
    curISRTimerData[i].previousMillis = startMillis;
    ISR_Timer.setInterval(curISRTimerData[i].TimerInterval, curISRTimerData[i].irqCallbackFunc);
#else
    previousMillis[i] = startMillis;
    ISR_Timer.setInterval(TimerInterval[i], irqCallbackFunc[i]);
#endif
  }

  // You need this timer for non-critical tasks. Avoid abusing ISR if not absolutely necessary.
  simpleTimer.setInterval(SIMPLE_TIMER_MS, simpleTimerDoingSomething2s);
}

#define BLOCKING_TIME_MS      10000L

void loop()
{
  // This unadvised blocking task is used to demonstrate the blocking effects onto the execution and accuracy to Software timer
  // You see the time elapse of ISR_Timer still accurate, whereas very unaccurate for Software Timer
  // The time elapse for 2000ms software timer now becomes 3000ms (BLOCKING_TIME_MS)
  // While that of ISR_Timer is still prefect.
  delay(BLOCKING_TIME_MS);

  // You need this Software timer for non-critical tasks. Avoid abusing ISR if not absolutely necessary
  // You don't need to and never call ISR_Timer.run() here in the loop(). It's already handled by ISR timer.
  simpleTimer.run();
}

Debug Terminal Output Samples

1. ISR_Timer_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A

The following is the sample terminal output when running example ISR_Timer_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A Ethernet and STM32Ethernet Library to demonstrate the accuracy of ISR Hardware Timer, especially when system is very busy. The ISR timer is programmed for 2s, is activated exactly after 2.000s !!!

While software timer, programmed for 2s, is activated after 9.782s !!!. Then in loop(), it's also activated every 3s.

Starting ISR_Timer_Complex on NUCLEO_F767ZI
STM32_TimerInterrupt v1.3.0
CPU Frequency = 216 MHz
[TISR] Timer Input Freq (Hz) = 216000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 10000.00 , _count = 100
Starting  ITimer OK, millis() = 6
[9] MAC:FE-E1-88-EC-DD-95
2s: Delta ms = 2000
2s: Delta ms = 2000
[6626] IP:192.168.2.116
[6626] 
    ___  __          __
   / _ )/ /_ _____  / /__
  / _  / / // / _ \/  '_/
 /____/_/\_, /_//_/_/\_\
        /___/ v0.6.1 on STM32 NUCLEO_F767ZI

[6636] BlynkArduinoClient.connect: Connecting to account.duckdns.org:8080
[6721] Ready (ping: 6ms).
IP = 192.168.2.116
2s: Delta ms = 2000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 9782
2s: Delta ms = 2000
5s: Delta ms = 5000
2s: Delta ms = 2000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
5s: Delta ms = 5000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
2s: Delta ms = 2000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
5s: Delta ms = 5000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
11s: Delta ms = 11000
2s: Delta ms = 2000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
5s: Delta ms = 5000
2s: Delta ms = 2000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
2s: Delta ms = 2000
5s: Delta ms = 5000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
11s: Delta ms = 11000
blynkDoingSomething2s: Delta programmed ms = 2000, actual = 3000
2s: Delta ms = 2000
5s: Delta ms = 5000
2s: Delta ms = 2000

2. TimerInterruptTest on STM32F7 Nucleo-144 NUCLEO_F767ZI

The following is the sample terminal output when running example TimerInterruptTest on STM32F7 Nucleo-144 NUCLEO_F767ZI to demonstrate how to start/stop Hardware Timers.

Starting TimerInterruptTest on NUCLEO_F767ZI
STM32_TimerInterrupt v1.3.0
CPU Frequency = 216 MHz
[TISR] Timer Input Freq (Hz) = 216000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 1.00 , _count = 1000000
Starting ITimer0 OK, millis() = 108
[TISR] Timer Input Freq (Hz) = 108000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 0.33 , _count = 3000000
Starting  ITimer1 OK, millis() = 119
Stop ITimer0, millis() = 5001
Start ITimer0, millis() = 10002
Stop ITimer1, millis() = 15001
Stop ITimer0, millis() = 15003
Start ITimer0, millis() = 20004
Stop ITimer0, millis() = 25005
Start ITimer1, millis() = 30002
Start ITimer0, millis() = 30006
Stop ITimer0, millis() = 35007
Start ITimer0, millis() = 40008
Stop ITimer1, millis() = 45003
Stop ITimer0, millis() = 45009
Start ITimer0, millis() = 50010
Stop ITimer0, millis() = 55011
Start ITimer1, millis() = 60004
Start ITimer0, millis() = 60012
Stop ITimer0, millis() = 65013
Start ITimer0, millis() = 70014
Stop ITimer1, millis() = 75005
Stop ITimer0, millis() = 75015
Start ITimer0, millis() = 80016
Stop ITimer0, millis() = 85017
Start ITimer1, millis() = 90006
Start ITimer0, millis() = 90018
Stop ITimer0, millis() = 95019
Start ITimer0, millis() = 100020
Stop ITimer1, millis() = 105007
Stop ITimer0, millis() = 105021
Start ITimer0, millis() = 110022
Stop ITimer0, millis() = 115023
Start ITimer1, millis() = 120008
Start ITimer0, millis() = 120024
Stop ITimer0, millis() = 125025
Start ITimer0, millis() = 130026
Stop ITimer1, millis() = 135009
Stop ITimer0, millis() = 135027
Start ITimer0, millis() = 140028

3. Argument_None on STM32F7 Nucleo-144 NUCLEO_F767ZI

The following is the sample terminal output when running example Argument_None on STM32G7 Nucleo-144 NUCLEO_F767ZI to demonstrate how to start/stop Multiple Hardware Timers.

Starting Argument_None on NUCLEO_F767ZI
STM32TimerInterrupt v1.3.0
CPU Frequency = 216 MHz
[TISR] Timer Input Freq (Hz) = 216000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 1.00 , _count = 1000000
Starting ITimer0 OK, millis() = 106
[TISR] Timer Input Freq (Hz) = 108000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 0.50 , _count = 2000000
Starting  ITimer1 OK, millis() = 117
[TISR] Timer Input Freq (Hz) = 108000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 0.20 , _count = 5000000
Starting  ITimer2 OK, millis() = 129
ITimer0: millis() = 1106, delta = 1000
ITimer0: millis() = 2106, delta = 1000
ITimer0: millis() = 3106, delta = 1000
ITimer0: millis() = 4106, delta = 1000
ITimer0: millis() = 5106, delta = 1000
ITimer1: millis() = 5118, delta = 5000
ITimer0: millis() = 6106, delta = 1000
ITimer0: millis() = 7106, delta = 1000
ITimer0: millis() = 8106, delta = 1000
ITimer0: millis() = 9106, delta = 1000
ITimer0: millis() = 10106, delta = 1000
ITimer1: millis() = 10118, delta = 5000
ITimer0: millis() = 11106, delta = 1000
ITimer0: millis() = 12106, delta = 1000
ITimer0: millis() = 13106, delta = 1000
ITimer0: millis() = 14106, delta = 1000
ITimer0: millis() = 15106, delta = 1000
ITimer1: millis() = 15118, delta = 5000
ITimer0: millis() = 16106, delta = 1000
ITimer0: millis() = 17106, delta = 1000
ITimer0: millis() = 18106, delta = 1000
ITimer0: millis() = 19106, delta = 1000
ITimer0: millis() = 20106, delta = 1000
ITimer1: millis() = 20118, delta = 5000
ITimer2: millis() = 20129, delta = 19999
ITimer0: millis() = 21106, delta = 1000
ITimer0: millis() = 22106, delta = 1000
ITimer0: millis() = 23106, delta = 1000
ITimer0: millis() = 24106, delta = 1000
ITimer0: millis() = 25106, delta = 1000
ITimer1: millis() = 25118, delta = 5000
ITimer0: millis() = 26106, delta = 1000
ITimer0: millis() = 27106, delta = 1000
ITimer0: millis() = 28106, delta = 1000
ITimer0: millis() = 29106, delta = 1000
ITimer0: millis() = 30106, delta = 1000
ITimer1: millis() = 30118, delta = 5000
ITimer0: millis() = 31106, delta = 1000
ITimer0: millis() = 32106, delta = 1000
ITimer0: millis() = 33106, delta = 1000
ITimer0: millis() = 34106, delta = 1000
ITimer0: millis() = 35106, delta = 1000
ITimer1: millis() = 35118, delta = 5000
ITimer0: millis() = 36106, delta = 1000
ITimer0: millis() = 37106, delta = 1000

4. Change_Interval on STM32F7 Nucleo-144 NUCLEO_F767ZI

The following is the sample terminal output when running example Change_Interval on STM32F7 Nucleo-144 NUCLEO_F767ZI to demonstrate how to change Timer Interval on-the-fly

Starting Change_Interval on NUCLEO_F767ZI
STM32TimerInterrupt v1.3.0
CPU Frequency = 216 MHz
[TISR] Timer Input Freq (Hz) = 216000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 2.00 , _count = 500000
Starting  Timer0 OK, millis() = 111
[TISR] Timer Input Freq (Hz) = 108000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 1.00 , _count = 1000000
Starting ITimer1 OK, millis() = 122
Time = 10001, Timer0Count = 20, , Timer1Count = 10
Time = 20002, Timer0Count = 40, , Timer1Count = 20
[TISR] STM32TimerInterrupt: Timer Input Freq (Hz) = 216000000
[TISR] Frequency = 1000000.00 , _count = 1000000
[TISR] STM32TimerInterrupt: Timer Input Freq (Hz) = 108000000
[TISR] Frequency = 1000000.00 , _count = 2000000
Changing Interval, Timer0 = 1000,  Timer1 = 2000
Time = 30003, Timer0Count = 50, , Timer1Count = 25
Time = 40004, Timer0Count = 60, , Timer1Count = 30

5. ISR_16_Timers_Array_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI

The following is the sample terminal output when running new example ISR_16_Timers_Array_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI to demonstrate the accuracy of ISR Hardware Timer, especially when system is very busy or blocked. The 16 independent ISR timers are programmed to be activated repetitively after certain intervals, is activated exactly after that programmed interval !!!

While software timer, programmed for 2s, is activated after 10.003s in loop()!!!.

In this example, 16 independent ISR Timers are used, yet utilized just one Hardware Timer. The Timer Intervals and Function Pointers are stored in arrays to facilitate the code modification.

Starting ISR_16_Timers_Array_Complex on NUCLEO_F767ZI
STM32_TimerInterrupt v1.3.0
CPU Frequency = 216 MHz
[TISR] Timer Input Freq (Hz) = 216000000 , Timer Clock Frequency = 1000000.00
[TISR] Timer Frequency = 100.00 , _count = 10000
Starting ITimer OK, millis() = 12
SimpleTimer : 2s, ms = 10015, Dms : 10003
Timer : 0, programmed : 5000, actual : 5010
Timer : 1, programmed : 10000, actual : 0
Timer : 2, programmed : 15000, actual : 0
Timer : 3, programmed : 20000, actual : 0
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 20073, Dms : 10058
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15010
Timer : 3, programmed : 20000, actual : 20010
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 30132, Dms : 10059
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20010
Timer : 4, programmed : 25000, actual : 25010
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 40192, Dms : 10060
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25010
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 50252, Dms : 10060
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 60313, Dms : 10061
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 70375, Dms : 10062
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 65010
Timer : 13, programmed : 70000, actual : 70010
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2s, ms = 80437, Dms : 10062
Timer : 0, programmed : 5000, actual : 4999
Timer : 1, programmed : 10000, actual : 9999
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 19999
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 39999
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 65010
Timer : 13, programmed : 70000, actual : 70010
Timer : 14, programmed : 75000, actual : 75010
Timer : 15, programmed : 80000, actual : 80009
SimpleTimer : 2s, ms = 90500, Dms : 10063
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 14999
Timer : 3, programmed : 20000, actual : 19999
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 29999
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 39999
Timer : 8, programmed : 45000, actual : 44999
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 65010
Timer : 13, programmed : 70000, actual : 70010
Timer : 14, programmed : 75000, actual : 75010
Timer : 15, programmed : 80000, actual : 80009

6. ISR_16_Timers_Array_Complex on STM32F1 BLUEPILL_F103C8

The following is the sample terminal output when running new example ISR_16_Timers_Array_Complex on STM32F1 BLUEPILL_F103C8 to demonstrate the accuracy of ISR Hardware Timer, especially when system is very busy or blocked. The 16 independent ISR timers are programmed to be activated repetitively after certain intervals, is activated exactly after that programmed interval !!!

While software timer, programmed for 2s, is activated after 10.000s in loop()!!!.

In this example, 16 independent ISR Timers are used, yet utilized just one Hardware Timer. The Timer Intervals and Function Pointers are stored in arrays to facilitate the code modification.

Starting ISR_16_Timers_Array_Complex on BLUEPILL_F103C8
STM32_TimerInterrupt v1.3.0
CPU Frequency = 72 MHz
Starting ITimer OK, millis() = 8880
SimpleTimer : 2, ms : 18880, Dms : 10000
Timer : 0, programmed : 5000, actual : 5001
Timer : 1, programmed : 10000, actual : 0
Timer : 2, programmed : 15000, actual : 0
Timer : 3, programmed : 20000, actual : 0
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 28881, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 38882, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 48883, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40000
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 58884, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40000
Timer : 8, programmed : 45000, actual : 45000
Timer : 9, programmed : 50000, actual : 50000
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 68885, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40000
Timer : 8, programmed : 45000, actual : 45000
Timer : 9, programmed : 50000, actual : 50000
Timer : 10, programmed : 55000, actual : 55000
Timer : 11, programmed : 60000, actual : 60000
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 78886, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40000
Timer : 8, programmed : 45000, actual : 45000
Timer : 9, programmed : 50000, actual : 50000
Timer : 10, programmed : 55000, actual : 55000
Timer : 11, programmed : 60000, actual : 60000
Timer : 12, programmed : 65000, actual : 65000
Timer : 13, programmed : 70000, actual : 70000
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 88887, Dms : 10001
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40000
Timer : 8, programmed : 45000, actual : 45000
Timer : 9, programmed : 50000, actual : 50000
Timer : 10, programmed : 55000, actual : 55000
Timer : 11, programmed : 60000, actual : 60000
Timer : 12, programmed : 65000, actual : 65000
Timer : 13, programmed : 70000, actual : 70000
Timer : 14, programmed : 75000, actual : 75000
Timer : 15, programmed : 80000, actual : 80000

7. ISR_16_Timers_Array_Complex on STM32H7 NUCLEO_H743ZI2

The following is the sample terminal output when running new example ISR_16_Timers_Array_Complex on STM32H7 NUCLEO_H743ZI2 to demonstrate the accuracy of ISR Hardware Timer, especially when system is very busy or blocked. The 16 independent ISR timers are programmed to be activated repetitively after certain intervals, is activated exactly after that programmed interval !!!

While software timer, programmed for 2s, is activated after 10.000s in loop()!!!.

In this example, 16 independent ISR Timers are used, yet utilized just one Hardware Timer. The Timer Intervals and Function Pointers are stored in arrays to facilitate the code modification.

Starting ISR_16_Timers_Array_Complex on NUCLEO_H743ZI2
STM32_TimerInterrupt v1.3.0
CPU Frequency = 480 MHz
Starting ITimer OK, millis() = 109
SimpleTimer : 2, ms : 10112, Dms : 10003
Timer : 0, programmed : 5000, actual : 5010
Timer : 1, programmed : 10000, actual : 10010
Timer : 2, programmed : 15000, actual : 0
Timer : 3, programmed : 20000, actual : 0
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 20176, Dms : 10064
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15010
Timer : 3, programmed : 20000, actual : 20010
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 30241, Dms : 10065
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20010
Timer : 4, programmed : 25000, actual : 25010
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 40306, Dms : 10065
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25010
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 50372, Dms : 10066
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 60439, Dms : 10067
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 9999
Timer : 2, programmed : 15000, actual : 14999
Timer : 3, programmed : 20000, actual : 19999
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 29999
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55009
Timer : 11, programmed : 60000, actual : 60009
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 70506, Dms : 10067
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 14999
Timer : 3, programmed : 20000, actual : 19999
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 29999
Timer : 6, programmed : 35000, actual : 34999
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55009
Timer : 11, programmed : 60000, actual : 60009
Timer : 12, programmed : 65000, actual : 65009
Timer : 13, programmed : 70000, actual : 70009
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 80574, Dms : 10068
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 24999
Timer : 5, programmed : 30000, actual : 29999
Timer : 6, programmed : 35000, actual : 34999
Timer : 7, programmed : 40000, actual : 39999
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55009
Timer : 11, programmed : 60000, actual : 60009
Timer : 12, programmed : 65000, actual : 65009
Timer : 13, programmed : 70000, actual : 70009
Timer : 14, programmed : 75000, actual : 75009
Timer : 15, programmed : 80000, actual : 80009

8. ISR_16_Timers_Array_Complex on STM32L5 NUCLEO_L552ZE_Q

The following is the sample terminal output when running new example ISR_16_Timers_Array_Complex on STM32L5 NUCLEO_L552ZE_Q to demonstrate the accuracy of ISR Hardware Timer, especially when system is very busy or blocked. The 16 independent ISR timers are programmed to be activated repetitively after certain intervals, is activated exactly after that programmed interval !!!

While software timer, programmed for 2s, is activated after 10.000s in loop()!!!.

In this example, 16 independent ISR Timers are used, yet utilized just one Hardware Timer. The Timer Intervals and Function Pointers are stored in arrays to facilitate the code modification.

Starting ISR_16_Timers_Array_Complex on NUCLEO_L552ZE_Q
STM32_TimerInterrupt v1.3.0
CPU Frequency = 110 MHz
Starting ITimer OK, millis() = 109
SimpleTimer : 2, ms : 10112, Dms : 10003
Timer : 0, programmed : 5000, actual : 5011
Timer : 1, programmed : 10000, actual : 10011
Timer : 2, programmed : 15000, actual : 0
Timer : 3, programmed : 20000, actual : 0
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 20177, Dms : 10065
Timer : 0, programmed : 5000, actual : 4999
Timer : 1, programmed : 10000, actual : 9999
Timer : 2, programmed : 15000, actual : 15011
Timer : 3, programmed : 20000, actual : 20010
Timer : 4, programmed : 25000, actual : 0
Timer : 5, programmed : 30000, actual : 0
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 30242, Dms : 10065
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 14999
Timer : 3, programmed : 20000, actual : 20010
Timer : 4, programmed : 25000, actual : 25010
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 0
Timer : 7, programmed : 40000, actual : 0
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 40308, Dms : 10066
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 14999
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25010
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 0
Timer : 9, programmed : 50000, actual : 0
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 50375, Dms : 10067
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30010
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 0
Timer : 11, programmed : 60000, actual : 0
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 60443, Dms : 10068
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35010
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 0
Timer : 13, programmed : 70000, actual : 0
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 70511, Dms : 10068
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40010
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 65010
Timer : 13, programmed : 70000, actual : 70010
Timer : 14, programmed : 75000, actual : 0
Timer : 15, programmed : 80000, actual : 0
SimpleTimer : 2, ms : 80580, Dms : 10069
Timer : 0, programmed : 5000, actual : 5000
Timer : 1, programmed : 10000, actual : 10000
Timer : 2, programmed : 15000, actual : 15000
Timer : 3, programmed : 20000, actual : 20000
Timer : 4, programmed : 25000, actual : 25000
Timer : 5, programmed : 30000, actual : 30000
Timer : 6, programmed : 35000, actual : 35000
Timer : 7, programmed : 40000, actual : 40000
Timer : 8, programmed : 45000, actual : 45010
Timer : 9, programmed : 50000, actual : 50010
Timer : 10, programmed : 55000, actual : 55010
Timer : 11, programmed : 60000, actual : 60010
Timer : 12, programmed : 65000, actual : 65010
Timer : 13, programmed : 70000, actual : 70010
Timer : 14, programmed : 75000, actual : 75010
Timer : 15, programmed : 80000, actual : 80010

Debug

Debug is enabled by default on Serial.

You can also change the debugging level (TIMERINTERRUPT_LOGLEVEL) from 0 to 4

// These define's must be placed at the beginning before #include "STM32_TimerInterrupt.h"
// _TIMERINTERRUPT_LOGLEVEL_ from 0 to 4
// Don't define _TIMERINTERRUPT_LOGLEVEL_ > 0. Only for special ISR debugging only. Can hang the system.
#define TIMER_INTERRUPT_DEBUG         0
#define _TIMERINTERRUPT_LOGLEVEL_     0

Troubleshooting

If you get compilation errors, more often than not, you may need to install a newer version of the core for Arduino boards.

Sometimes, the library will only work if you update the board core to the latest version because I am using newly added functions.

Issues

Submit issues to: STM32_TimerInterrupt issues

TO DO

Search for bug and improvement.
Similar features for remaining Arduino boards such as SAM-DUE

DONE

Basic hardware timers for STM32.
More hardware-initiated software-enabled timers
Longer time interval
Similar features for remaining Arduino boards such as ESP32, ESP8266, SAMD21, SAMD51, nRF52, mbed-nRF52, Teensy, etc.
Add Table of Contents
Add support to STM32L5 (NUCLEO_L552ZE_Q)
Fix multiple-definitions linker error. Drop src_cpp and src_h directories

Contributions and Thanks

Many thanks for everyone for bug reporting, new feature suggesting, testing and contributing to the development of this library.

Contributing

If you want to contribute to this project:

Report bugs and errors
Ask for enhancements
Create issues and pull requests
Tell other people about this library

License

The library is licensed under MIT

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khoih-prog / STM32_TimerInterrupt

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STM32_TimerInterrupt Library

Table of Contents

Why do we need this STM32_TimerInterrupt library

Features

Why using ISR-based Hardware Timer Interrupt is better

Currently supported Boards

Important Notes about ISR

Prerequisites

Installation

Use Arduino Library Manager

Manual Install

VS Code & PlatformIO

Libraries' Patches

Notes: These patches are totally optional and necessary only when you use the related Ethernet library and get certain error or issues.

1. For application requiring 2K+ HTML page

2. For Ethernet library

3. For EthernetLarge library

4. For Ethernet2 library

5. For Ethernet3 library

6. For UIPEthernet library

7. For fixing ESP32 compile error

8. For STM32 core F3 and F4 using UIPEthernet library

HOWTO Fix Multiple Definitions Linker Error

More useful Information about STM32 Timers

New from v1.0.0

Usage

1. Using only Hardware Timer directly

1.1 Init Hardware Timer

1.2 Set Hardware Timer Interval and attach Timer Interrupt Handler function

2. Using 16 ISR_based Timers from 1 Hardware Timer

2.1 Init Hardware Timer and ISR-based Timer

2.2 Set Hardware Timer Interval and attach Timer Interrupt Handler functions

Examples:

Example ISR_16_Timers_Array_Complex

Debug Terminal Output Samples

1. ISR_Timer_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI using Built-in LAN8742A

2. TimerInterruptTest on STM32F7 Nucleo-144 NUCLEO_F767ZI

3. Argument_None on STM32F7 Nucleo-144 NUCLEO_F767ZI

4. Change_Interval on STM32F7 Nucleo-144 NUCLEO_F767ZI

5. ISR_16_Timers_Array_Complex on STM32F7 Nucleo-144 NUCLEO_F767ZI

6. ISR_16_Timers_Array_Complex on STM32F1 BLUEPILL_F103C8

7. ISR_16_Timers_Array_Complex on STM32H7 NUCLEO_H743ZI2

8. ISR_16_Timers_Array_Complex on STM32L5 NUCLEO_L552ZE_Q

Debug

Troubleshooting

Issues

TO DO

DONE

Contributions and Thanks

Contributing

License

Copyright

HOWTO Fix `Multiple Definitions` Linker Error