Rob writes –
Guido knew the secret to a perfect cuppa. It’s all in the timing. So he designed a battery-powered tea timer with a built-in LED display that will brew a perfect cup of tea every time. It’s simple: just fix a tea-bag on the tea timer’s extension arm, place a mug of hot water underneath it and push a button according to how strong you like your tea. The microcontroller-operated, 5V circuit provides a servo motor with control pulses to lower and raise the arm and the power supply is switched off automatically via FET.
DIY Tea timer – Link.