By default the heartbeat LED flashes in blue colour once every 4s to signal that the system is alive. This can be overridden through the pycom module.
import pycom pycom.heartbeat(False) pycom.rgbled(0xff00) # turn on the RGB LED in green colour
The heartbeat LED is also used to indicate that an error was detected.
The following piece of code uses the RGB LED to make a traffic light that runs for 10 cycles.
import pycom import time pycom.heartbeat(False) for cycles in range(10): # stop after 10 cycles pycom.rgbled(0x007f00) # green time.sleep(5) pycom.rgbled(0x7f7f00) # yellow time.sleep(1.5) pycom.rgbled(0x7f0000) # red time.sleep(4)
Here is the expected result: