Norwegian company 7Sense has launched a cellular IoT irrigation sensor capable of water leak detection and location monitoring for sprinkler carts. The ‘7Sense Irrigation Sensor Gen III’ is designed for use on farms, and can be easily retrofitted to almost any type of legacy irrigation system. Alerts and notifications about water leaks, the sprinkler’s location, speed and estimated finish time are transmitted to the Cloud via Nordic’s nRF9160 low power SiP’s multimode LTE-M/NB-IoT modem.
The nRF9160’s powerful 64 MHz Arm® Cortex®-M33 application processor provides the necessary computational power for the sensor to monitor and analyze the micro vibrations in the water pipe. Changes in these vibrations indicate a change in flow and potential leak. Using a combination of cellular network location data and GNSS and 7Sense’s proprietary Cloud service, the device also provides precise position monitoring for sprinkler carts. This enables farmers to be notified when carts pass certain points, or let them know if a cart has overturned or stopped moving.
Using a lithium primary battery cell, the irrigation sensor can function for up to two years between battery replacements, thanks, to the low power consumption of the nRF9160 SiP, which supports both PSM and eDRX power saving modes. For both LTE-M and NB-IoT the PSM floor current is as low as 2.7 µA, and with an eDRX interval of 655 s the average current is 6 µA for LTE-M and 9 µA for NB-IoT.