Prototyping Battery Powered Sensors with MySensors

Hi Everyone,

Recently I’ve been prototyping some sensors with MySensors, with the aim of them being battery powered for deployment in the garden. Initially I’ve deployed a sensor for my mini greenhouse to keep an eye on my seedlings, however I’ve been having some radio range issues. I’ve written up my experiences so far:

Please let me know what you think!

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Nice! Are you planning to automate the opening door or watering/misting the plants?
Regarding the range, the RF modules would benefit from a small 10-100uF 6.3/10V cap across the power closest to the module.

Thanks! The door is a roll up plastic sheet (like a tent), so it would be tricky to automate. I’m considering a DIY irrigation system for the rest of the garden, so the greenhouse may get included.

Thanks for the tip about the caps, I’ll give that a try and see if it helps.

You may be interested in this ultra low power remote temperature+ sensor I built. I calculate that it draws about 65 uA on average from a Lipo battery, reports temperature, humidity and pressure over a distance of at least 100 ft.
The remote hardware is based on Moteino M0 with a BME280 sensor and RFM69 radio soldered on the Moteino modules. No extra wiring is required. The Arduino code is here.
It sleeps 5 minutes between measurements to save power. For other applications like a remote contact sensor (burglar alarm) the code could be modified to wake up the CPU and transmit on an external interrupt.

I used a ESP8266 and a RFM96 radio module to built a MySensors gateway using MQTT over Wifi to Hassio. The Arduino code is from a fairly standard example. I used a dipole antenna from lowpowerlab to get good radio range. The Gateway runs off an AC power adapter in the house.

If I had a greenhouse, I would want to automate more. I would want to turn on a fan, open a vent and irrigate. That would require running AC power to the greenhouse and eliminate the need for battery operation. The RFM69 radio is still useful because of its superior range when compared to WiFi. Around my house, I still prefer my AC powered WiFi IOT modules as they don’t have to go through the MySensors Gateway.

As a follow up to this, I’ve fixed the reception issue I was having by moving the gateway closer and proxying the data via Node-RED and MQTT:

I’m still going to adjust the hardware to add a cap for increased radio range, but I’m waiting for the parts to arrive! In the meantime, I’ve basically built an MQTT gateway without needing any extra hardware (other than what was already deployed).