WiSense network for monitoring water level in big tanks
Any large community/campus in India usually has a network of water tanks to store and supply water. Community managers in Inda are very interested in knowing the water level in these tanks at all times thanks to erratic water supply (municipal or private tankers). One of our customers requires an SMS to be sent every time the water level in any tank goes above or below fixed threshold. They also want to have a history of the levels in every tank. This customer has tanks in multiple locations across the campus and most locations have multiple co-located tanks. One location has five tanks. Since It is not practical to have a GSM modem for each tank, we proposed a network of WiSense nodes in each location. The WiSense gateway node in each location will interface with a GSM modem. Locations which are close enough can also share a single GSM modem. This week we showed a POC using three WiSense nodes. Two were sensor nodes which used pressure sensors to continuously monitor the water level in two separate tanks. The third was a gateway node connected to a GSM modem. This sensor network was successfully able to track the water levels in both tanks. We configured the gateway node to send an SMS every 5 minutes to a campus manager’s cell phone. Each SMS reported the water level (in inches).
The sensor nodes were powered by two AAA batteries. Both nodes were configured to operate as reduced function devices (RFD). The water level sensing was done using the Freescale MP3V5050GP ported pressure sensor. A flexible food grade tube (tied to a weight) was lowered into each tank such that one end rested at the bottom of the tank. The other end was attached to the MP3V5050GP’s port. The sensor then measured the pressure of the water column.
Here are some pics of the POC.