i2C is not multithreading safe #1074
Description
When using background threads to read the sensors and the main thread to update the screen the board hangs.
A simple program like this hangs after few seconds:
#include <Arduino.h>
#include <mbed.h>
#include <RGB_LED.h>
#include <I2C.h>
#include <HTS221Sensor.h>
Thread _background;
RGB_LED led;
DevI2C* i2c;
HTS221Sensor* sensor;
void setupSensor(){
i2c = new DevI2C(D14, D15);
sensor = new HTS221Sensor(*i2c); //Temperature and Humidity Sensor
sensor -> init(NULL); // init the sensor
sensor -> enable();// enable
// read id
unsigned char id;
sensor -> readId(&id);
Serial.printf("HTS221 ID: %d\r\n", id);
}
void readSensor(){
// get humidity
float humidity, temperature;
sensor -> getHumidity(&humidity);
Serial.printf("Humidity: %.1f%%\n\r",humidity);
// get temperature
sensor -> getTemperature(&temperature);
Serial.printf("Temperature: %.1fC\n\r",temperature);
}
static void backgroundTask(){
while(1){
led.setColor(0,5,0);
delay(500);
led.turnOff();
delay(500);
readSensor();
}
}
void setup(){
Serial.begin(115200);
Screen.init();
Screen.print("Setup");
setupSensor();
readSensor();
_background.start(&backgroundTask);
Screen.print("Setup Complete");
}
unsigned long uptime=0;
void loop(){
Serial.println(uptime++);
delay(1000);
readSensor();
Screen.print(3,"..");
}