The Chocolate board contains a light sensor, temperature sensor, and buttons. The following video demonstrates each of them briefly:
In each case watch the LED that is indicated with the keyring in the video. The board is running an image that changes the LED colours based on various sensor readings.
Firstly, we test the temperature sensor. The light on the lower right of the video changes in response to temperature changes. One way to artificially raise the temperature on a temperature sensor IC is to hold your finger on it. It is a little hard to see, but the LED slowly gains an orange tinge as the temperature rises.
Secondly, we test the light sensor. The LED on the far right of the video becomes more green as the light sensor detects more light. The sensor itself is located in the corner of the board on the bottom left of the video. We shine a light near the sensor, but not on it. We then move the light closer to the actual sensor location. The more light the sensor receives, the more the LED changes, until it is an extremely bright green.
Next, we test the buttons. The LED on the top left of the video changes colour as we press each of the four buttons on the board.
The Chocolate board contains a voltage sensor and a Li-Po battery charger with charge status output. This is a little difficult to demonstrate due to the time taken to charge. However we can still observe the change in charge status by disconnecting and reconnecting the USB cable. This can be seen in the following video: