ESP32 Forum

Posted: **Tue Apr 13, 2021 7:08 am**

Dear All,
I am trying to use timers and I2C simultaneously, for which I have initialized timer and I2c in void setup(), but after initializing only the timer is working and I2C is working, however, if I initialize I2C before the timer in the setup, I2C is working but the timer is not. So, I created a new task where I am initializing I2C. Since I have two I2C sensors with the same address, and whose address cannot be changed, I have two initialize two I2C buses. Now after initializing both the I2C buses in the same task, I cannot access data from the second I2C sensor(initialized on a new I2C bus). I feel that there are some issues in using the timer and I2C simultaneously, I am not able to solve them. Kindly help me with this issue.

Code: Select all


void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
Serial.println("Test Code for SFM3300");
Initialize_Timer();
//I2C_Default.begin(SDA1,SCL1);
//I2C_New.begin(SDA2,SCL2);
//FlowSensor_Ins.begin(&I2C_Default);
//FlowSensor_Exp.begin(&I2C_New);
//FlowSensor_Ins.Start_Measurement();
//FlowSensor_Exp.Start_Measurement();        /* pin task to core 0 */  
xTaskCreatePinnedToCore(
    DisplayFlowTask,   /* Task function. */
    "Task2",     /* name of task. */
    10000,       /* Stack size of task */
    NULL,        /* parameter of the task */
    1,           /* priority of the task */
    &Task2,      /* Task handle to keep track of created task */
    0);    
delay(1000);
 
//FlowSensor_Ins.Start_Measurement();
}
uint16_t RawFlowVal_Exp=0;
uint16_t RawFlowVal_Ins=0;
float Flow_Exp,Flow_Ins=0;
void loop() 
{ 
  // put your main code here, to run repeatedly:
//  Serial.println("================================================================");
//  Serial.print("Flow Expiratory:");
  delay(100);
}
void Initialize_Timer(void) {
  // Use 1st timer of 4 
  timer2 = timerBegin(2, 80, true);                                                 /* 1 tick take 1/(80MHZ/80) = 1us so we set divider 80 and count up */
  //  timer1 = timerBegin(1, 80, true);
  timerAttachInterrupt(timer2, &onTimer2, true);                                    /* Attach onTimer function to our timer */
  //  timerAttachInterrupt(timer1, &onTimer1, true);
// Repeat the alarm (third parameter) /
  timerAlarmWrite(timer2, 1000000, true);                                            /* Set alarm to call onTimer function every second 1 tick is 1us => 1 second is 1000000us */
  //  timerAlarmWrite(timer1, GI16u_http_post_delay * 1000, true);
  timerAlarmEnable(timer2);                                                         /* Start an alarm */
  //  timerAlarmDisable(timer1);
}

void IRAM_ATTR onTimer2(void) 
{ 
 Count++;
}

void DisplayFlowTask( void * pvParameters ) 
{ 
  I2C_Default.begin(SDA1,SCL1);
  FlowSensor_Ins.begin(&I2C_Default);
  FlowSensor_Ins.Start_Measurement();
  I2C_New.begin(SDA2,SCL2);
  FlowSensor_Exp.begin(&I2C_New);
  FlowSensor_Exp.Start_Measurement();
  delay(1000);
  for (;;) 
  {
//    Serial.println("From Task2");
    Serial.println("***********************");
    Serial.println("Flow Inspiratory:");
    RawFlowVal_Ins=FlowSensor_Ins.ReadFlowVal();
    Flow_Ins = (((float)RawFlowVal_Ins - 32768) / 120);
    Serial.println(Flow_Ins);
    Serial.print("Timer Count:");Serial.println(Count);
    RawFlowVal_Exp=FlowSensor_Exp.ReadFlowVal();
    Flow_Exp = (((float)RawFlowVal_Exp - 32768) / 120);
    Serial.print("Final Exp:");
    Serial.println(Flow_Exp);
    Serial.println("--------------------");
    delay(2000);
  }
}

ESP32 Forum

Cannot Use I2C and Timer Simultaneously

Cannot Use I2C and Timer Simultaneously