Capacitive sense test
Using the new analogue inputs we can now sense a finger touching metal contact 0. To use while the Exclamation is showing (!) make sure you don't touch the unit at all as it gets a baseline for the floating input. Once this has gone you can then touch sensor zero (without needing to hold GND in another hand) and you should see the display change from a cross to a tick. If you add a wire to input 0 this affects the input, so you can reset the baseline by pressing A and waiting (without touching the wire or bug). B button puts it to sleep, press A to re-awaken and reset.