C code is not working?

  • Check your wiring for problems.

  • Check if the code is reporting errors, if so, refer to: Install and Check the WiringPi.

  • Has the code been compiled before running.

  • If all the above 3 conditions are OK, it may be that your wiringPi version (2.50) is not compatible with your Raspberry Pi 4B and above, refer to Install and Check the WiringPi to manually upgrade it to version 2.52.