IEC 62056-21 Optical Interface

This article discusses an optical interface designed for communication with various devices using the IEC62056-21 standard, commonly utilized with different types of meters, though not limited to them.

INFO

The interface can be purchased on Tindie

Features

• Compatible with devices using the IEC62056-21 interface
• Designed for pinout compatibility with the Wemos Mini layout
• Supports both 3.3V and 5.0V logic levels
• Operates with a power supply range of 3.3V to 5V

Pinout

Pins without a label are not connected

Specification

• Power: 3.3V-5V
• Logic level: 3.3V or 5V
• Infrared wavelength: 850-940nm
• Transmission: half-duplex
• PCB
  • Diameter: ⌀30mm ±0.2mm
  • Material: FR4
  • Color: Black
  • Thickness: 1.6mm
  • Surface Finish: Lead Free

PCB Dimensions

Pinout compatible with

• ESP8266 D1 mini
• ESP32 D1 mini
• ESP32 S2 mini
• ESP32 C3 mini

How to connect

Do not cross RX/TX signals.

Optical Interface	Microcontroller
VCC	3.3V or 5V
GND	GND
TX	TX
RX	RX

Arduino

Before uploading the sketch disconnect TX and RX lines.

Raspberry Pi