SDS011
SDS011 particle matter sensor library for the Arduino framework for ESP8266 and ESP32.
This is yet another SDS011 library, this time completely non blocling. It does come with a loop()-method to poll the serial port.
Installation
- For Arduino IDE: see the Arduino Guide
- For Platformio: see the Platfomio guide
Usage
You cannot use Serial on ESP8266 as there's only 1 full UART available which will be used by the sensor.
To do something useful you can combine this lib with MQTT (like async-mqtt-client) as in the example below.
#include <ESP8266WiFi.h>
#include <Ticker.h>
#include <AsyncMqttClient.h>
#include <SDS011.h>
const char SSID[] = "My_WiFi";
const char PASS[] = "My_Pass";
const IPAddress BROKER = {192, 168, 1, 10};
SDS011 sds011;
AsyncMqttClient mqttClient;
Ticker mqttReconnectTimer;
WiFiEventHandler wifiConnectHandler;
WiFiEventHandler wifiDisconnectHandler;
Ticker wifiReconnectTimer;
bool connected = false;
void connectToWifi() {
WiFi.begin(SSID, PASS);
}
void onWifiConnect(const WiFiEventStationModeGotIP& event) {
connectToMqtt();
}
void onWifiDisconnect(const WiFiEventStationModeDisconnected& event) {
mqttReconnectTimer.detach(); // ensure we don't reconnect to MQTT while reconnecting to Wi-Fi
wifiReconnectTimer.once(2, connectToWifi);
}
void connectToMqtt() {
mqttClient.connect();
}
void onMqttConnected(bool sessionPresent) {
connected = true;
}
void onMqttDisconnect(AsyncMqttClientDisconnectReason reason) {
connected = false;
if (WiFi.isConnected()) {
mqttReconnectTimer.once(2, connectToMqtt);
}
}
void setup() {
wifiConnectHandler = WiFi.onStationModeGotIP(onWifiConnect);
wifiDisconnectHandler = WiFi.onStationModeDisconnected(onWifiDisconnect);
mqttClient.onConnect(onMqttConnected);
mqttClient.onDisconnect(onMqttDisconnect);
mqttClient.setServer(BROKER, 1883);
sds011.setup(&Serial);
sds011.onData([](float pm25Value, float pm10Value) {
if (connected) {
mqttClient.publish("/SENSOR/PM2_5", 1, false, String(pm25Value, 1).c_str());
mqttClient.publish("/SENSOR/PM10", 1, false, String(pm10Value, 1).c_str());
}
});
sds011.onResponse([](uint8_t command, uint8_t set, uint8_t result){
// command has been executed
});
sds011.onError([](int8_t error){
// error happened
// -1: CRC error
});
sds011.setWorkingPeriod(5);
connectToWifi();
}
void loop() {
sds011.loop();
}
To Do
- adjust readings based on humidity
- possible timeout after sending a command
- implement missing commands
- multiple sensors (apparently the firmware supports this. However, they implemented hardware using 1-1 UART) ???
Issues, improvements?
Please create a ticket or pull request.