The schematic and the shield

On the STM32F7-Discovery there are a ARDUINO interface so i did make a little PCB to make the connections to the keyer.

In teh scematic i did use the knowledge from my experiment with "wetting current" http://oz1jhm.dk/content/wetting-current-and-cw-paddles

You can make your own board or very easy make it on a prototype board for a Arduino UNO