AirMeter Mod Streams Multimeter Readings Live to a Browser via ESP32

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A YouTuber known as Bits und Bolts has built AirMeter, an open-source hardware mod that wirelessly streams live readings from an ANENG AN870 multimeter to a web browser or OBS. The project was created to solve the common filming problem of glare, focus hunting, and awkward camera angles when capturing multimeter screens. Because the meter's built-in UART port is physically disabled under epoxy, the mod instead uses an RP2040 microcontroller to directly sample the LCD's multiplexed analog signals, which are then converted to clean digital levels using LM339 comparators. The decoded readings are transmitted over a 433 MHz HC-12 radio link to an ESP32-C3, which hosts a local web page that faithfully recreates the meter's display. All schematics, board files, and firmware are publicly available, and the method can be adapted to other budget multimeters built on the same DTM0660 chip.

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