M-Bus UART converter

Simple M-Bus to 3.3V UART level converter for 1..3 M-Bus slave devices. Board is designed to fit into off-the-shelve Kradex Z105 DIN enclosure. The board has an on-board 5V to 34V boost converter. UART input has an optional low voltage drop diode for the ESP8266 microcontrollers that do not boot when the TX line is pulled down.


  • M-Bus voltage: 34 V
  • M-Bus slaves: 1..3
  • UART level: 3.3 V
  • UART connector: 3.5mm screw terminal
  • Supply voltage: 5 VDC
  • Fuse: 500mA @ 6V
  • Short circuit protection: none
  • Single layer PCB
  • Dimensions: 86x14mm
  • Board fits into Kradex Z105 DIN enclosure



  • Bare PCB: 3€ 

  • Pre-assembled: 25€

  • Pre-assembled with terminals: 30€

  • Pre-assembled with terminals and DIN enclosure: 35€