Problem using Wire.h and GSM.h togheter - Arduino keeps rebooting.


I am working on a small project where I use an Arduino Uno R3 to receive data (a heartrate) from the internet by using an Arduino GSM Shield 2. This same arduino uses the wire.h library to communicate with a second Arduino Uno R3 which makes a pin “beat” with the same heartrate.

Now there’s a problem that I can’t get my head around:
When I comment everything that considers the I²C-communication, the Arduino Uno reads his data in by connecting to the internet using the Arduino GSM Shield 2.
When I comment the code that updates the heartrate from the internet, the I²C-connection to the second arduino works fine.
When I use them togheter, the Arduino starts and after completing the setup, the first time he updates his data from the internet the Arduino reboots.

I already checked following things:

  • The power supply can deliver 2.5 Amps, while the GSM Shield could use around 1 Amp.
  • The sketch uses about 60% of the memory on the board.

You can find the code in the attachment, as well as the Serial Monitor from the different scenarios as described before.

If you have any questions, just ask. I would like to solve this issue!

Thanks in advance! :slight_smile:

Collect data from webserver.txt (808 Bytes)

Data exchange using I²C.txt (288 Bytes)

Using both GSM.h & Wire.h - Rebooting.txt (270 Bytes)

HRM_GSM_Receiver.ino (11.9 KB)