RaspberryPi3, Python and Circuits 3

The next circuit to have a go at is this mercury tilt-switch activated countdown timer. Useful for making an alarm.

Extension activities could include changing the activation red LED for a relay to switch higher voltages (drive a motor for example) and add a one-time on switch to activate or deactivate the circuit, such as a keypad driven IR detector or RFID tag.

Python code and video of the circuit running to follow.