The Uni-Trends UT61E multimeter includes an optical output so that data can be read using a computer. The multimeter ships with an RS232(-ish) cable that clips into the multimeter and provides a DB9 connector.
This module plugs into the DB9 connector on the supplied cable, and reads the data using an ESP8266 on a Wemos D1 Mini. The data can then be reported via USB or WiFi.
The example firmware reports the raw data via the USB port and also to an MQTT broker. It also shows the boot state using the RGB LED, and then blinks each time a data packet is processed.
This project was collaboratively designed on the SuperHouse livestream with the assistance of viewers.
- Fully assembled including the Wemos D1 Mini and a cable.
- DB9 plug for connection to multimeter cable.
- Wemos D1 Mini with USB and WiFi.
- Powered via USB cable.
- WS2812B RGB LED to show connection status and activity.