Remote Water Tank Level Monitoring
This unit is based on a waterproof ultrasonic sensor that determines the depth of water, or other liquid in a tank. The sensor wirelessly relays tank depth, temperature and battery information back to a base station that publishes a graph of the data on the Internet and also implements and alarm function if the water level drops too rapidly or below a minimum. The alarm function notifies users via their smart phone.
The wireless uses a 6LoWPAN, self-healing, ‘sleepy’ mesh protocol. This enables intermediate mesh nodes to relay data whilst still sleeping most of the time to save power.
The unit operates using a small rechargeable lithium-ion battery and small solar panel that together can keep the device running almost indefinitely.
In addition to the main radio board we designed the efficient solar charger that is used by the unit and also a ‘boost n shift’ board that supplies 5 volts to the ultrasonic sensor module.
We are currently working on a significant enhancement where the tank water supply will be controlled by a motorised ball valve, depending on both the level of water in the tank and the production of water from the hillside spring that is several hundred meters from the tank. The sensor mote and motorised ball valve will be powered from the same, small. lithium ion rechargable battery, plus small 6V, 3Watts solar panel. At the same time the radio network will be upgraded from 2.4 GHz to sub-GHz at 915 MHz. The latter will enable longer range at less power.