I'm new to this forum so I present myself a little, I have a project ongoing now which is a remote soil monitoring, powered with a 12v battery recharged by solar panel. The system use Arduino MKR GSM 1400 with SIM card and 3g connection.
I have problems in reliability and stability. Arduino board hangs some time, and it seems the internal WDT does not intervene efficiently.
So now I have a Dual WatchDog Timer Board and I'm trying to connect to an Arduino MKR GSM 1400.
The connection scheme is:
JP2 Dog1 Arduino Reset -> Arduino Reset Pin JP Dog1 Input -> Arduino digital pin 1 Power GND -> Arduino GND pin Power VDD -> Arduino VCC (3.3V out)
The Arduino in powered by USB cable from my laptop.
The problem is: when I connect the DWT, the Arduino IDE does not see the Arduino MKR board.
If I power off the DWT disconnecting VDD, the Arduino IDE sees again the Arduino MKR board.
PS. If I connect the Power VDD to 5V output instead of 3.3V, the Charge LED of Arduino flashes continuously without stopping and the Arduino IDE does not see the Arduino MKR board, the same.
Sorry for this late reply. I think the main difference with other Arduinos is that MKR Arduino RESET PIN is operating at 3.3V. A part from this, I believe the way it works should be the same like other Arduinos. No, I do not have UNO or MEGA.
If I connect the VDD to 5V or 3.3V (VCC pin of Arduino), the result is the same: the builtin led of Arduino flashes on-off and the LED01 of DWT flashes on-off, while the LED02 is always on, and the Arduino IDE does not see the MKR.