AVR-projects

This repository contains a growing collection of individual AVR project files for various tasks. I personally use these projects as starting points for new microcontroller projects, or reference for common procedudures I would otherwise have to go back to the datasheet for (timers, counters, frequency counting or synthesis, interrupts, UART, I2C, ADC, etc). Each folder is self-contained and has batch scripts to set fuses to change the clock source (internal RC oscillator at 8MHz, div/8 for 1MHz, or external crystal typically up to 20 MHz)

These are some of my favorites:

• Blink an LED with an ATTiny45, ATTiny2313, or ATMega328
• sending data from a microcontroller to a PC with USART (likely via USB serial port)
  • USART for ATTiny2313
  • ATMega328 wired or over bluetooth
  • interrupt driven vs. polling method for USART input
• PWM for ATTiny2313 or PWM for ATTiny85
• code to interface with a rotary encoder
• ultra minimal frequency generator I use for all sorts of stuff
• code to read ADC values and send them over serial with ATMega328 (including code for ADC noise reduction mode)

Programming Setup

I almost always use AVRISPmkII and AVRdude (launched from a batch script) to program my chips. I virtually never use AVRStudio. I typically develop in a Windows environment, but the code (and AVRdude) works the same in Linux.

Software

• Just install WinAVR and it should install drivers for common programmers.
• I prefer to edit C code in Notepad++
• definately check out AVRDudess (a GUI for AVRdude) as an easy GUI to load flash onto chips

Hardware

• AVR Programming in 64-bit Windows 7 (should also work for windows 10)
• windows 10 driver for USBTiny is here
• actually I only got it to work after installing Zadig

Programmers

Note	Picture
AVRISPmkII is a ceap, fast, and convenient AVR programmer.
Bus Pirate technically can program AVRs, but it's so slow it's not practical. Here's a post I wrote about it. I like the bus pirate when I need to use software to measure voltages and toggle pins. It's slow though, because the handshake it bit-banged and it takes tens of seconds to program an AVR. For just programming, I prefer an (ebay knockoff) AVR ISP mkII. Definately check out AVRDudess as a GUI for AVRDude. I usually get a standard command for a project and put it in a batch file in the same folder.
AVRDudess can simplify programming of code and fuses.

Common AVR Datasheets and Pinouts

chip	pinout	datasheets
ATMega328		[summary] [complete]
ATTiny2313		[summary] [complete]
ATTiny45		[summary] [complete]

Helpful Links

• AVR fuse calculator
• AVR timer calculator

Misc Code

Reading pins

if(PIND&(1<<PD7)){doSomething();} // runs doSomething() if PD7 is HIGH

Bit flipping in C

PORTD|=(1<<PD6); // sets PD6 high
PORTD&=~(1<<PD6); // sets PD6 low
PORTD^=(1<<PD6); // flips the state of PD6

Memory-Efficient Timers

#include <util/delay.h>
void waitMs1(){_delay_ms(1);}
void waitMs(int ms){while (ms-->0){waitMs1();}}
void waitSec(int sec){while (sec-->0){waitMs(1000);}}