back to uC, PIC16F87X

[Paul Maddox]

Mikko/Roel,

  Ive built a single channel Midi>CV using the AVR and
also built Midi>LCD (shows note/octave and gate status).

  I havent programmed Asembler for a long long time (10 years+)
and it only took me about 3 days to pick up the AVR asembler,
its quick easy and logical, the flash eprom for program and for
data is soooo handy, its ISP and this is another godsave. 
  There are plenty of resources for the AVR , www.avr-forum.com
and even a mail list (to which Im subscribed as ais someone else on
the synthdiy list ;-) ). Atmel are VERY helpful, and the STK200 comes
with software and examples, it really is a well thought out starter kit.
Oh BTW its also cheap, 40UKP gets you the STK200/8515/software.

  I now have a working 4 channel Midi>CV/gate/velo, though I havent 
yet cracked it working with midinote off (it responds to midi 
noteon+velo=0 as a gate off) this wont take long though.

  I intend to to put this into a rack for my modular, it'll give me 
4 channels, with the 4 VCO's I have and the other planned 4
this will be enough for me. Its a fixed channel module (11,12,13,14)
though it wouldn't take much mroe to add a rotary switch to
detect a channel selector.

  details will be available soon..

  Paul

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-----Original Message-----
From:	Mikko Helin [SMTP:helin at uta.fi]
Sent:	Friday, October 22, 1999 3:38 PM
To:	stew at uq.net.au
Cc:	roelrules at yahoo.com; synth-diy at mailhost.bpa.nl
Subject:	Re: back to uC, PIC16F87X


Hello,

I've written a draft on using the PIC16F877 for MIDI-CV etc.
If there are more people who liked to have something like
this done we could build & program a prototype and
then have the pcb's made somewhere. So how's that?

The URL for the draft is 

http://www.uta.fi/~helin/midipic.pdf

-Mikko


> Hi Roel,
> 
> The F87x will be fine for this, though personally I'd use an AVR
> microcontroller. However if you already know pic assembly language that
> would be the best way to go. If not I think the STK200
> programmer/development board for the AVR is about 35 pounds(including a 40
> pin 8515 micro with UART, 3 timers and 8k flash ROM).And the silicon is
> cheaper than PICs if you know where to get them. 
> 
> A good use for the A/D would be for a menu system:
> 
> Have an LCD or 7seg LED display for readout.
> Say for example you want to edit the midi channel....
> 1. Read the pot value (potval). 
> 2. swap potval so the upper 4 bits are now the lower 4 bits.
> 3. And potval with 00001111 to mask out the top nibble.
> 4. You now have midi channel 0-15. You can store this as the midi channel.
> If you want to display the midi channel just copy and increment this
> channel so that channel zero displays channel one.
> 
> You can do this for all kind of parameters, changing it depending on how
> many values you need. eg. if you wanted 255 values you can use the direct
> value that you read from the A/D.  
> 
> Hope this Helps (and not confuses!)
> stewart pye
> 
> 
> At 11:22 AM 15/10/99 -0700, Roel Das wrote:
> >Just a little more on the microcontrollers...
> >I'm designing a midi-cv as part of my endworkproject. 
> >Any recommandations on the processor? It should be
> >VERY complete, nice interface and things...
> >I can get a programmer and emulator-board for the
> >microchip PIC16F87X series (20MHz, up to 5 I/O's,
> >USART,up to 8 10bits ADC's,... and more) at school for
> >about 90 Euro. The chips themselve cost 10 to 25 euro,
> >i believe. 
> >Would this be an ok deal? 
> >Is the usart usable for MIDI?
> >Any way to make use of the ADC? Controlknobs maybe?
> >Thank you very much.
> >smile
> >Roel
> >__________________________________________________
> >Do You Yahoo!?
> >Bid and sell for free at http://auctions.yahoo.com
> >
> >
> 
>