Hi everyone!
I just wanted to share my recent MySensors project setup focused on indoor environment monitoring. I’ve been gradually building a home automation system, and MySensors has been a perfect fit for its flexibility and low power requirements.
Here’s a breakdown of my current configuration:
💡 Sensor Node Configuration:
Microcontroller: Arduino Pro Mini 3.3V 8MHz (clone from HiLetgo)
Wireless Module: NRF24L01+ with 10µF capacitor for stability
Environmental Sensor: BME280 (https://www.ichome.com/product-detail/bosch-sensortec/bme280#PdfShow) for temperature, humidity, and pressure (connected via I2C)
Power: 2x AA batteries + step-up booster (using an HT7333 LDO for stable voltage)(https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/5057/HT73xx-A.pdf)
Additional Modules (planned):
BH1750 for ambient light sensing
TSL2561 as a more accurate alternative
📡 Gateway Setup:
Controller: Home Assistant (via MySensors MQTT integration)
Gateway Type: MQTT Gateway
Hardware:
Arduino Nano + NRF24L01+
Connected to a Raspberry Pi 4B (4GB RAM) running Mosquitto MQTT Broker
Powering the gateway with USB + filtered 3.3V rail for NRF stability
🧠 Software:
MySensors Library Version: 2.3.2
Using the MySensors BME280 example sketch with slight modifications to add battery reporting (sendBatteryLevel()).
MQTT topics structured as: mysensors-out/0/1/1/0/0 etc.
🔧 Challenges & Solutions:
Interference: Had to add a 10µF electrolytic cap close to the NRF24L01+ VCC pin to prevent random disconnects.
Power Optimization: Removed voltage regulator & power LED from the Pro Mini, sleep cycles set to 10 minutes to save battery.
Signal Range: Improved range with a NRF24L01+ PA/LNA module and external antenna for the gateway.
🚀 Next Steps:
Integrating motion detection using HC-SR501(https://www.youtube.com/watch?v=QizfU7Fgmyw) PIR sensor
Adding OTA update capability via MYSBootloader (still exploring)
Possibly shifting to RFM69 for better range in multi-room setup
If anyone has experience optimizing BME280 accuracy or recommendations for better battery life, I’d love to hear your thoughts!