By examining the :ref:`quickref`, we see that ``X1`` is connected to channel 1 of timer 5 (``TIM5 CH1``). Therefore we will first create a ``Timer`` object for timer 5, then create a ``TimerChannel`` object for channel 1::
from pyb import Timer
from timer import sleep
from time import sleep
# timer 5 will be created with a frequency of 100 Hz
