Saturday 9 February 2013

Arduino DDS Shield

Following the fun-and-games I had with the little eBay AD9850 DDS module in Raspberry Pi land, I decided to follow Ron's inspiration even more literally than before and team up the module with an Arduino.

Or, at least, with my homebrewed "Wotduino".

Here's the schematic I developed in Eagle...

I represented the DDS module as a component in Eagle and was intending to upload the library to the CadSoft site for you to share, but CadSoft claim not to recognise my email address (despite the fact that there's another library of mine already there, proudly displaying said email address). Stuff it then - collaboration can wait 'til another day.

The module only took up a small fraction of the available area on the shield, so I added a couple of dual flip-flops to generate a quadrature squarewave output for future games with Tayloe detectors.

Here's my copper plan...

Here's the finished board, seen from above...

You can see where I had to gnaw away a little of the Module PCB (lower right) to fit with the DIL package - there wasn't quite so much space in real life as my Eagle board layout suggested!

This being my first ever experience of a Wotduino shield (much less an Arduino shield) I was interested to get some pukka "stackable headers" to allow the new shield to ride shotgun atop the Wotduino...

The board works a treat - the picture above is actually part of an impromptu 40m QRP CW rig I've lashed together today using the Wotduino. It works nicely - well enough to raise Terry, g4ayr, on the rig's first shout. But just as Terry and I started to talk, the band erupted with a crowd of speed freaks sending - . ... -, so I'll wait until things have calmed down before I strike up my genteel iddy umpty again.

Perhaps I'll use the wait to start writing some Wotduino beacon code.

 ...-.- de m0xpd


  1. Great project, I have the DDS module and am thinking of using it for a small project of my own. Could you let me have a copy of the eagle file for the DDS module?

    Steve 2E0NLW

    1. It is on the "Occam's Microcontroller" Support page...
      It is far from perfect - but good enough for my needs!
      73 Paul m0xpd