Saga of the uP developer

[Tim Ressel]

I appreciate the warm, twitchy welcome ... but I've been doing <twitch> embedded
designs <twitch> since 1981 <twitch> <twitch>. Been there, done that, got a
whole closet of t-shirts. 

<brag mode on>
Short list of nightmares, the likes of which Alice Cooper has never seen:

6809 coprocessor card in an Apple 2E so we can run "Legacy code"
6809 to 68000 "Transliterator" so we don't have to re-write a billion lines of
assembly...
A triple-68000 VME system with shared-memory communications <twitch>
A massively-paralleled 68020 super computer (the ULTIMATE embedded system!)
Home-automation distributed-processing system with RS-485 comm links
<brag mode off>

Compared to this, a uP adsr seems child's play! Except the processor may not be
fast enough for 1mS 2-channel updates <twitch>...


Tim Ressel--Compliance Engineer
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com                     



-----Original Message-----
From: patchell [mailto:patchell at silcom.com]
Sent: Monday, June 26, 2000 5:41 PM
To: Tim Ressel
Cc: synth-diy at node12b53.a2000.nl
Subject: Re: Saga of the uP developer




Tim Ressel wrote:

> Let this be a warning to anyone who thinks they want to develop uP devices:
Have
> your debugging skills honed o a keen edge!
>
> So, I got the uP ADSR hardware in working order. Then I wrote some test code
to
> output a ramp; just incremented a counter and sent the results to te DACs.
What
> I saw on the scope was a series of small ramps with gaps in between. After
much
> head scratching. I discovered my new development system (miniIDE) was making
> HC12 code, not HC11 code. Fixed that, still had the odd ramps. More scratching
> of various body parts. Then it finally hit me: out of the two jumpers setting
> the mode of the HC11 I had pulled the wrong one, thus putting the uP into
> "Special Test" mode instead of "single chip" mode. Apparently special test
mode
> toggles all of the output lines in counter-like fashion. The output to DACs
was
> remarkably similar to the ramps I had programmed! Sigh...
>
> The clue, by the way, was some of the lines were toggling at the uP clock
rate.
> A physical impossiblity under program control.
>
> So now the ADSR hardware works, and my development system works as well. I am
> all set to code the ADSR. Now if I could only find the sheet with the state
> diagrams I made....
>
> Stay Tuned.
>

    Welcome to the amazing world of "Embedded Systems Design".  Just wait until
you
do your first project that has 3000 pages of source code (I don't recomend doing
that many all on your own, I will never do it again).  You get a call from a
third
hand party describing a problem, and you can't reproduce it in the lab, so you
dive
into the code.....well it does get ugly.  Even with a logic analyzer (by the
way, an
HP 1672), it can sometimes take three days to track down a single problem,
especially when the cause was created 50000 instruction fetches before the event
you
were able to trigger on.

    Plus the side benifits.....although...<twitch> I don't <twitch> twitch as
much
<twitch> as I did a couple of months ago <twitch><twitch>.

    -Jim

>
> Tim Ressel--Compliance Engineer
> Hewlett-Packard
> Verifone Division
> 916-630-2541
> tim_r1 at verifone.com
>
> -----Original Message-----
> From: Hallvard Tangeraas [mailto:hall at oslo.online.no]
> Sent: Monday, June 26, 2000 6:53 AM
> To: synth-diy at node12b53.a2000.nl
> Subject: Re: MIDI to Sync24 Converter - and other pic goodies!
>
> At 10:44 +0200  26-06-2000, tomg wrote:
>
> >List member - Bojan Burkeljc has a MIDI to Sync24 Converter Pic project
> >on his site (includes the hex).....Actually there is a lot of midi
> >stuff...
>   [......]
>
> Great stuff! I'll be checking out all those websites you mentioned.
> But in case I don't find what I need, does anyone know of a DIY project
> which will add MIDI IN to my Roland TR-808 drum machine?
> Has anyone here MIDIed their TR-808?
>
> I don't want to spend a fortune on this, but it would be nice to be
> able to have MIDI on it, instead of having to reply on DIN 24 sync or
> sampling the drum sounds!
>
> Hallvard
> --
> Hyperlink Launchpad: <http://www.crosswinds.net/~hall/>
> Atari Launchpad    : <http://launchpad.atari.org>
> Notator/Creator SL : <http://www.crosswinds.net/~notator/>

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