Project : Token tap

This logger is developed to monitor the usage of public water taps. The time stamps of the opening of the valve and time it is opened is stored on a flash chip and can be read out via bluetooth. The energy consumplion is extremely low: 4 μA and is supplied by a 3.7 V 400 mAh LiPo battery. Not much solar energy is needed to keep the battery fully charged, so the 5.5 V, 70 mA solar panel is more than sufficient. To make it water proof the PCB will be cast in epoxy.