Another day, Another Sensor

This time, We interfaced a rain detection sensor to a WiSense WSN1101L wireless mesh node. This is another component in our smart community test bed at Pruksa (East Bangalore).

We are  using  the RG-11 rain sensor from Hyderon. It has multiple modes  of operation. In the “rain detection” mode, the RG-11 output turns on when a given rate of rainfall is detected, and turns off after it has dropped below a threshold. The output remains on for between about 30 seconds and 5 minutes after the last detected rain drop, depending on sensitivity setting and actual conditions.

The RG-11 output voltage goes high (to supply voltage) when the  sensor  turns on. We have interfaced this output signal to a GPIO  pin on the WSN1101L’s micro (MSP430G2955) through a voltage divider  + op-amp circuit. The op-amp output goes high when rain is detected and remains low otherwise.

The  rain detector  sensor node has a simple output – 1 if it is raining, 0 otherwise. This information is being sent continuously to WiSight (our cloud platform running on  AWS).

The RG-11  requires a  minimum of 12  Volts to operate. We get this supply from a  wall wart. This supply is also converted  to 3.3  V to run the WSN1101L .  As you can  see in the pic  below, the  WSN1101L and associated electronics  is enclosed  in a  weather proof  enclosure. The antenna is  mounted outside.



One use case is to send an SMS  alert to residents who want to be informed when it just starts to rain. Smart watering (of private and public green spaces) can use this  information to decide whether to water on a particular day or not.



Snapshot of WiSight (running on AWS) showing data from the RG-11 sensor node.




RG-11 user guide:


For more information please visit

Posted on August 7, 2016, in Uncategorized. Bookmark the permalink. 1 Comment.

  1. digtal display bill boards can sense rain and automaticall show ads for umbrellas,gumboots,raincoats and vicks vaporub caps plastic folders whenever it starts raining

    hotels serving on terrace can shift to indoors as soon as rainsensor sends alarm

    or roof canopy can be activated to cover

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