BT785

Introduction

This page is about reverse engineering the BT-785, an inexpensive Tuya-compatible water electrical conductivity (EC) meter. It measures EC and temperature, and has a display and communicates its reading over Bluetooth Low-Energy (BLE) to the Tuya app on a phone. The goal is to understand the communication protocol so we can communicate with it from the raspberry pi in the Karaburan project.

Analysis

On the lowest level, it uses bluetooth low-level with the GATT profile: