SAJ R5 Inverter via BLE

Hi all,

Wanted to share this because i can imagine there are others who would like to read the data (near) real-time from their inverters.

I do not have the ability to change modules of modify other connections to ‘my’ inverter because of the rental obligations. So, i made it my personal quest/learning process for to read the data via BLE.

And luckily, i succeeded.

SAJ solar inverters (R5 series) via Bluetooth Low Energy (BLE). Communicates directly with the inverter’s DTU (MC20 2G module) using Modbus over BLE — no cloud, no Wi-Fi required.

Features

  • Auto-discovery of SAJ inverters via Bluetooth
  • Real-time solar production monitoring
  • Configurable polling interval (10–300 seconds)

Be aware, i had only my own setup to test this. I use a usb BT dongle, at a distance of 5-6meters. Hopefully i can help someone else by posting this.

Screenhot: