I was thinking about something similar. Have you seen SPROG?
As far as I have seen so far they do ready built kits but i'm waiting
to be accepted on their yahoo group so I can find out more.
The SPROG II homepage is at
Personally what I have read suggests it is a bit limited. I think £40
is slightly overpriced but then i don't know exactly what components
go into it.
You can read their forum at:
We don't actually sell the kits anymore. The prices on the web page are
for fully assembled, tested units.
Members of MERG can buy kits for the older SPROG (functionally the
same, but uses a larger PCB and some metal bashing is needed for the
case). Be aware that these kits use surface mount components.
I'm always interested in feedback.
What limitations do you perceive? Used with DecoderPro, SPROG II can
program virtually any decoder, including most sound decoders which are
notoriously difficult, sometimes requiring additional "programming
boosters" with other commercial systems.
The price is for a fully assembled unit, not a kit, so you are paying
for someone's time as well as the components.
I can only comment as a satisfied customer, but SPROG is invaluable, and
well worth the £50 (I bought the USB version). I can now program
decoders in any way possible, and using the decoder pro software tweak
away to my hearts content.