How to solve a conflict with RTCZero and attachInterrupt

Good evening all,

I am actually programing a Adafruit Feather MO with a AMD21 cortex processor as the Arduino Zero.

I connected a rain gauge in A4 to count the drops AND to wakeup the board when it’s in sleep mode.

I use the library RTCZero to put the board in Sleep mode.

Here is how I set up the intterup on A4

 const int pin_arrosage = A4;        // A4 of Feather board
void setup() {
pinMode(pin_arrosage, INPUT_PULLUP);
    //digitalWrite(pin_arrosage, LOW);
    attachInterrupt(digitalPinToInterrupt(pin_arrosage), triggeredDropArrosage, CHANGE);

void triggeredDropArrosage()
    led_state = !led_state;
  delayMicroseconds(100000); // Without this, it does not count 1+1

When the bunket move from a side to another side, the drops is counted fine.
The above code work fine until I setup the RTCzero library.

With TRCzero, at the some point, we have to setup the interrupt, which willwakeup the board after a laps of time


I observed that wehn the above line is uncommented, the drops is counted 5-7 time and then the terminal do not answer, freez. It’s look like if the board stop running.

Here is the code about the RTCZero configuration. I will add anode where the RTCZero interrupt is actived.

First I add the library

#define LOWPOWER
#if defined(LOWPOWER)
  //#include <LowPower.h>
  #include <RTCZero.h>
  /* Create an rtc object */
  RTCZero sleep;
  // Set how often alarm goes off here
  // If you change the frequence, do not forget to adapte
  // for (int i=0; i<int(TX_INTERVAL/10); i++) { in complete event, lin 469
  const byte alarmSeconds = 10;
  const byte alarmMinutes = 0;
  const byte alarmHours = 0;

Then in setup() below the drop interrupt, I added this

    pinMode(pin_arrosage, INPUT_PULLUP);
    //digitalWrite(pin_arrosage, LOW);
    attachInterrupt(digitalPinToInterrupt(pin_arrosage), triggeredDropArrosage, CHANGE);


// When I comment the following line, my rain gauge counts the drop
// When I uncomment it, it's look like if thee is a conflict the the attachInterrupt of he rain gauge, because the drops are counted 4-8 time before the terminal stop displaying the Serial.print of the loop()

The following functions are need by the above code and works fine.

void rtczero_resetAlarm(){
  #if defined(LOWPOWER)
    // Variable to set a reference in the time.
    byte seconds = 0;
    byte minutes = 0;
    byte hours = 0;
    byte day = 1;
    byte month = 1;
    byte year = 1;
    // Set time reference
    sleep.setTime(hours, minutes, seconds);
    sleep.setDate(day, month, year);

    // set alarm (wake up RTCZero)
    sleep.setAlarmTime(alarmHours, alarmMinutes, alarmSeconds); //  By default we set at 10 sec, 0 mn, 0 hours

void triggeredAlarm(){
  #if defined(LOWPOWER)

void rtczero_sleep(){
  #if defined(LOWPOWER)
    sleep.standbyMode(); // Sleep until next alarm match

As since I commented


my rain gaude work fine.The drop are counted because of the first interrupt

attachInterrupt(digitalPinToInterrupt(pin_arrosage), triggeredDropArrosage, CHANGE);

I wonder if both interrupt can work together as two interrupt are define.

How can I make sure that none of the interrupts, do not disturb each other???

I pain your attention that my problem become before putting my board in sleep mode

Many thank for your help and suggestion

In other work, I think you understand, I want to put in sleep mode my board with RTCZero library and I want to be able to wakeup my board with the clock of RTCZero or with the rain guage, just for the time to count the drops, and then it immeditaly goes back to the sleeping mode.

Or if you have any suggesion to count the drops while the board is in sleep mode, your suggestion are welcome :) !!

1015 posts, and you still haven't read this

Installation & Troubleshooting For problems with Arduino itself, NOT your project

. :o

Dear AWOL,

AWOL: 1015 posts, and you still haven't read this . :o

I'm sorry for this inattention

I solved my problem as the following but let me know if you are agree with me.

I kept this commented


In fact, RTCZero generate a interrupt to wakup the board, but I personely do not need an action when RTCZero wakeup the board. So, I removed the function triggeredAlarm()

It look like my board sleep and wakeup after 1mn.