Finally I finished my ‘new’ keyer based upon the famous K3NG design. I used a standard Arduino Uno board and made my own shield and enclosure.
To be able to ‘control’ two transceivers I decided to add two outputs, one for each transceiver. By holding the first memory for a longer period ( > 1 second) the first output is active, holding the second button will active the output for transceiver two. All this functionality can be selected by making changes in the source code, I could not add all the features I wanted because the memory of the Uno is limited to 32K whereof the Mega has more space for code.
The keyer can be powered by a DC voltage between 8 and 14 volt or over USB.
At the same time added a metal base plate to my old paddles, not very exciting but it does do the job!
It is made of 10 x 10 x 1 cm steel plate, milled into the right shape.