[time-nuts] Simple open source microcontroller solution to tune DDS needed

[Richard (Rick) Karlquist]

I need a very simple controller to tune a DDS with up/down
switches (imagine setting the time on a clock).  A DDS
chip, such as an AD9836 would go on a PC board and a couple
of pushbuttons would tell the controller to tune up or
down.

Before reinventing this wheel, I thought I would see if
anyone knows of a similar solution that can be leveraged.
What I would like is both hardware and software, where
the software could be edited to accommodate the up/down
buttons.  A last resort would be to write software from
scratch.  My software skills are extremely limited.
Cutting and pasting code might work for me.

I need to be able to embed this onto an existing PC board.
I can't use a preexisting "daughter" card, other than
to copy the design of the card.

Rick Karlquist
N6RK