Implement function to brick/disable the SIM800L

[RedBulletTooling]

If you only have permission of a company to monitor keystrokes for a certain amount of time, it is whished to have a "remote detonation" button. So no data is send anymore, but the KEYVILBOARD stays working.

Most easy way seems to be to enter the SIM800L into sleep mode 1. You would need physical access to get it out of that sleep mode, which should be hardcore enough.

https://www.raviyp.com/embedded/223-sim900-sim800-sleep-mode-at-commands

[whid-injector]

Use a transistor to drive PWRKEY (in my case I used D2) and use D13 to drive RST.

void setup() {
  Keyboard.begin();

  // ------ Initialize SIM800 ------
  pinMode(13, OUTPUT);
  digitalWrite(13, HIGH); 
  pinMode(2, OUTPUT);
  digitalWrite(2, HIGH); 
  delay(1000);
  digitalWrite(2, LOW); 
  // ------ Initialize SIM800 ------

Then you can create an SMS ad-hoc to shutdown the SIM800 forever.

[RedBulletTooling]

@whid-injector Thanks for your input! I added it to the improvements for our next hardware version. As our current design does not have access to the PWRKEY of the SIM800L, I think a software solutions is best for now. Otherwise people would have to mess with the hardware, which will cause more trouble than problems it saves.