Sim900 D9 Issue

Hello guys,

I'm currently working on getting the SIM900 to power up when required.

below is the code to power it.

void SIM900power()
// software equivalent of pressing the GSM shield "power" button
  digitalWrite(9, HIGH);
  digitalWrite(9, LOW);

I'm using a broad that's identical to this.


I have read alot of the tutorials and they all mention that i need to "solder two JP pads, that are very close to D9"

The problem is that i'm unable to find these JP pads, so I'm wondering if someone else has came along this issue and could point me into the right direction.

Thank you.

Maybe it is on the other side of the board?

You need to find the schematic for that shield to see which pin it is using for power. It doesn’t appear to have the pads next to D8 & D9.


were you able to find these pins ?