Test the IR Receiver Circuit

Let's check that your infrared receiver circuit is wired properly and that your remote was programmed correctly. This program displays the numbers from the infrared remote on the micro:bit’s LED display. This example provides an easy way to determine the number associated with each key on the remote (especially the non-numbered CH and VOL keys).

cyber:bot demonstrating IR receiver functions.

  • Add the tv_remote module to your micro:bit, the same way you added the cyberbot module before. For a refresher, see Add modules to your micro:bit.
  • Enter, save and flash IR_Remote_Test.py.
  • Put the cyber:bot board’s power switch in position 1.
  • Point the remote at the IR receiver on the board, and then press and release a number on the remote. You should see the number displayed on the LED matrix.
# IR_Remote_Test.py            

from cyberbot import *
from tv_remote import *

bot(22).tone(2000, 300)

while True:
    num = ir(10).remote()
    if num > -1:
        display.scroll( str(num), 75, wait=False )


IR Interference — Are you seeing numbers appear on the micro:bit LED matrix when you are NOT pressing any numbers on the remote?

First, check to see if you are getting a syntax error report from your micro:bit. 

If that’s not the problem, your IR receiver might be getting signals similar to a TV remote’s signals from some other source. The most common culprit is overhead fluorescent light fixtures. If possible, turn them off or try taking your robot to a different area.