ATmega on DIN Rail

The need for this module came from the Energy Counter project where a board with a micro-controller with a generic I/O interface (non-isolated) was needed. Some brief search on the Internet didn't show anything as simple as what I need for this project. My requirements were very basic and these are the features of this module:

• Micro-controller based module - ATMEGA88A-AUR
• Compact solution - width equivalent to a power breaker - 17.5mm
• Direct access to the micro-controller GPIOs - Up to 16 GPIOs available
• Front-panel with:
  • Power status LED - Green
  • Buzzer
  • Controllable LED - Red
  • Push-button
• Powered by 24V
• ESD protection on each GPIO
• Connection for AVR ISP
• Connection for Debug Display board
• 10MHz Xtal oscillator
• Power supply monitoring and reset generation
• Reset push-button

The figure below shows the high-level architecture of the ATmegaOnDIN module. ESD protections are not shown.

This modules required up to 20 connections in just 3 cm² and this required a very compact connector.
It uses connectors with 2.5mm pitch with push-in spring connection:

Each position can connect to solid wires with section between 0.14 mm² and 0.5 mm² or flexible connectors with section between 0.2 mm² and 0.5 mm² or between 24 and 20 AWG.

Version 1

The first version of the module was originally used for Energy Counter project:

This version has a small mechanical conflict with the solid top of the DIN rail module which needed to be cut out.