#Raspberry Pi
2 articles
Hardware / IoT
Reading a DTSU666 3-Phase Meter with Raspberry Pi over Modbus RS485
Notes on connecting a DTSU666 Smart Power Sensor to a Raspberry Pi over RS485, reading 3-phase electrical measurements from multiple meters using Modbus RTU, decoding 32-bit floats correctly, and storing them in SQLite/MySQL before exporting through MQTT and a REST API, including a negative-value bug I ran into myself
Reading Modbus RTU over an RS485 Gateway Without Phantom Values
Connecting multiple Modbus RTU meters/sensors on an RS485 bus through a serial-to-Ethernet gateway can produce phantom values, incorrect readings, or devices that do not actually exist — because a transparent gateway uses RTU-over-TCP, which requires assembling frames and calculating CRC yourself, and validating every reply. This article covers the rules I learned from doing it.