Re: A very Hacky Holidays

[Warren <ve3wwg@gmail.com>]

R Tyler Croy expounded in
news:slrnigna8d.b8b.tyler@kiwi.local: 

> On 2010-12-17, Warren <ve3wwg@gmail.com> wrote:
>> R Tyler Croy expounded in
>> news:slrnigl66m.b8b.tyler@kiwi.local: 
>>
>>> For me Ada is relegated to being used in my free time, a
>>> lot of which I will be having to hack on things over the
>>> upcoming vacation. 
>>> 
>>> I wanted to ask you all what you may/may not be hacking
>>> on over the break, perhaps we could cheer each other on
>>> ;) 
>>> 
>>> A little positive reenforcement from your peers can never
>>> hurt :) 
>>
>> I've been working on an analog synthesizer. My MIDI module
>> uses an ATmega168 using code written in Ada (thanks to
>> Rolf's AVR-Ada project). My MIDI module seems to be
>> exhibiting key rollover problems, which won't be hard to
>> fix. I just need to add a nested "Note On" counter, so
>> that I don't prematurely execute a physical "Note Off".
>>
>> The code is written in two tasks (actually threads under
>> AVR-Ada). The main task processes MIDI events and queues
>> some events for the 2nd task. The 2nd task takes care of
>> waking up at the right time (via timeouts) and performing
>> ADSR voltage changes (DAC # 2) and creation of trigger and
>> gate signals (digital outputs). Pitch is also established
>> by sending a value to the first DAC, using an SPI
>> interface. 
>>
>> My original code was all C-ish Arduino stuff, which I was
>> not very happy with. When I discovered AVR-Ada, I jumped
>> at the opportunity and rewrote it all in Ada. It is so
>> much nicer to work with and Ada actually pointed out a
>> couple of previously hidden bugs (in the C code).
>>
>> My latest adventures with the recently built VCA synth
>> module, can be found below (there is at least one picture
>> of the MIDI module in there somewhere):
>>
>> http://experimentalistsanonymous.com/board/index.php?topic=
>> 2445.0
>>
>> ( http://tinyurl.com/2d2p9vh )
>>
>> I don't think you need to be a member to view the forum.
>>
>> Merry Christmas and Hacky New Year!
> 
> Wow, sweet project! I was wondering when an AVR-Ada user
> was going to pipe up with a neat project.

Embedded work is so much more fun when using Ada, so I 
couldn't resist.

> Does Ada have a theme song you'll be able to pipe through
> the device? 

I have a bunch of work yet to do before it will be playing any 
tunes. At a minimum I still need to build a VCO (oscillator 
for pitch), VCF (filter) and LFO (low freq oscillator). 
However, it is all great homebrewed electronic fun.

An analog synth (like this one) is normally only capable of 
one note at a time (monophonic). So it will take some multi-
tracked recording to do anything interesting with it.  But 
that is not a problem. All in due time....

Warren