Sry if this is an obvious question, I'm not that experienced with arduinos. I have a grove beginner kit for arduino (https://wiki.seeedstudio.com/Grove-Beginner-Kit-For-Arduino/) and I have a bottletics sim7000 shield and an adafruit datalogging shield. I want to stack the two shields on top of the arduino, but whenever I do and I run a sample code, the serial monitor returns random characters. I've been researching the reasons for this and I've read that it's due to both shields using the same pins but I'm still very lost. Does anyone know how to resolve this issue? Thank you!
The problem is that the Adafruit data logger shield uses pins 10 and 11, and so does the Botletics SIM7000 shield. The easiest solution would be to change the pins that the SIM7000 uses, because the Adafruit board has to use pin 11 (MOSI) for the SPI communication protocol. You could change the pins used on the Botletics shield for UART communication on pins 10 and 11 to pins 4 and 5, for example. Here's what to do:
Stack the Adafruit board onto the Arduino first
Stack the Botletics board on top of the Adafruit board, but bend the metal contacts on pins 10 and 11 outwards slightly, so that they don't go into the Adafruit board below. (Pins 10-11 on the Botletics board are physically connected to the SIM7000 module on board, so you'll need those connections, but you don't want them to be confused with pins 10-11 on the Adafruit board).
Put a jumper wire from pin 10 over to pin 4. Put another one from pin 11 to pin 5. Because pins 4-5 are still connected all the way down to the Arduino through the Adafruit shield, you'll use those pin numbers in your Arduino sketch instead of 10-11, and they will be connected to the SIM7000 module without being connected to the Adafruit board.
And voila! Let me know if you have any other questions... 😊
Thank you for getting back so quickly! I just have a clarifying question for your last bullet point. For the jumper wire, the pin 10/11 is pin 10/11 of the Botletics board correct? Is the jumper wire connecting pin 10/11 of the Botletics board to pin 4/5 of the Botletics board or pin 4/5 of the Adafruit board (or pin 4/5 of the Arduino)? Thx again!