[sdiy] DIY PG-800?

[Matthew Smith]

Quoth Luís Marka at 2008-12-26 00:11...
> Also got curious about the possibility of building a PG800 for my JX8P, 
> and I could find the difficult parts (the uPD7001C and the uPD8048HC) at 
> utsource.net: $10.00 each. Not that bad!
> So if you guys get to read the firmware from a PG800 I am very likely to 
> build one for myself!

The nice thing about it is the use of standard components - at least 
they were standard when it was made.

However, if I could get to the bottom of the serial protocol, I would 
prefer to NOT just reproduce the original.  I'd use an Atmel AVR for the 
CPU (because I am used to them and it's nice to be able to re-programme 
in-circuit) and substitute a current ADC.  In fact I might go for 16 
channel ADCs rather than multiplexing and then using a single one.

The main reason that I would like to do my own version is that I would 
be able to publish schematics and firmware under a Creative Commons 
license - totally legally.  (The Roland firmware would, of course, be 
subject to copyright.  Copying it for a single unit would probably not 
upset anyone but publishing it on the Web would be asking for a nasty 
letter from Roland's lawyers.  Maybe Roland would like to start 
Open-Sourcing its old firmware ;-))

Cheers

M

-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
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