Example: turn on an LED

Note This example is only for kits that use the XBIB-U-DEV development board. For an example that uses the XBIB-CU-TH development board, see Example: Turn on an LED.

  1. Note the DS4 LED on the XBIB board. The following image highlights it in a red box. The LED is normally off.

  1. At the MicroPython >>> prompt, type the commands below, pressing Enter after each one. After entering the last line of code, the LED illuminates. Anything after a # symbol is a comment, and you do not need to type it.

Note You can easily copy and paste code from the online version of this guide. Use caution with the PDF version, as it may not maintain essential indentations.

import machine
from machine import Pin
led = Pin("D4", Pin.OUT, value=0)  # Makes a pin object set to output 0.
# One might expect 0 to mean OFF and 1 to mean ON, and this is normally the case. 
# But the LED we are turning on and off is setup as what is# known as "active low".
# This means setting the pin to 0 allows current to flow through the LED and then through the pin, to ground.
  1. To turn it off, type the following and press Enter:
led.value(1)

You have successfully controlled an LED on the board using basic I/O.