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.

Version 2

The second version of this module was created to correct/improve the module mechanics.
In the picture below the two versions of the modules can be seen together. The one in the left (not fully assembled) kept the solid top on the front plate.