D1 Mini DIN Rail Case 1TE, RS485

thingiverse

This thing is a DIN rail case that holds a Wemos D1 Mini clone and a cheap MAX485 PCB. It was built to send Eastron SDM120 energy meter values to an MQTT broker using a cheap ESP8266-based board and RS485 terminal blocks. The case provides space for 5V power (+ and -) and screw terminal blocks, giving you access to the reset button from the top and Micro USB for updating your software. You'll also need to print clips, holders, and covers to assemble the project. To complete this build, you'll need: * A Wemos D1 Mini clone * A MAX485 module (TTL to RS485) * 2 screw terminal blocks (0 or 90 degrees) * Wires with DuPont connectors (optional) * A spring (5.5mm diameter and 15.5mm long) * An external DIN rail 5V power supply The software needed is an ESP8266-based board firmware, such as esp-sdm-mqtt from GitHub. Connections include: * 5V + Screw terminal <--> MAX485 VCC <--> D1 Mini 5V * 5V - Screw terminal <--> MAX485 GND <--> D1 Mini G * D1 Mini Pin D1 <--> MAX485 RO * D1 Mini Pin D2 <--> MAX485 DI * D1 Mini Pin D4 <--> MAX485 RE and DE (bridge the two pins) * RS485 A Screw terminal <--> MAX485 A * RS485 B Screw terminal <--> MAX485 B Notes: * The screw terminal blocks I used were different models, so top and bottom holders are slightly different. * Cheap cables soldered on the D1 mini tend to break, but a connector can be used instead. * Redesign for a current rev 3.1.0 Wemos D1 mini is recommended. Changes: * The source file has been requested in comments for easier editing. Unfortunately, final Sketchup files are not available due to needing some final fixing. The attached files should be considered building blocks for remixing.