Display an error number and stop the program.


If your board has some way to display error information, ||control:panic|| will work with it to show error numbers.

Your program stops when you use ||control:panic||. Use this when you think something bad enough has happened and your program can’t run properly anymore.


  • code: an error number you match to an error situation in your program.

System error codes

The micro:bit has error codes reserved for use by the system software. The panic() function is for advanced usage only. You must carefully chose an error code that doesn’t match one currently used by the micro:bit system.


Send a ‘code red’ error that you created to the error display if the input from pin P0 is lower than 10.

let codeRed = 1110;
let codeBlue = 1111;

if (pins.analogReadPin(AnalogPin.P0) < 10) {

See also

assert, error codes