[sdiy] OBJECT ORIENTED C in synth programming

[Scott Gravenhorst]

dan snazelle <subjectivity at hotmail.com> wrote:
>Ok
>
>While we are on the topic of Learning about TYPEDEF's and 
>STRUCTURES, can anyone recommend a book that covers C in relation 
>to AVRs well? 
>
>The reason I ask is that the C books I have, so often fall back 
>on using PRINT as their example. 
>
>It would be great to have a book on C that related things to the 
>world of ADCs and DACS and TIMERS. 

Welcome to the world of digital design.

While printf et al works great with a screen, you are correct that such
an expression is useless where there is no screen.

I've not worked with an AVR, but I have worked with PICs, other
microprocessors and FPGA development boards.  Such things will often
have LEDs that can be controlled by the micro or other device. 
Sometimes that's all you get and sometimes not even that.  

In my work, I've managed to survive with only a few LEDs (8 if I'm
lucky), an oscope and the DAC.  I can route information to the LEDs -
that's pretty easy.  But sometimes I need different information.  I can
scope the DAC to see if anything is happening at all (perhaps way to
slow to hear or maybe using so few bits that I can't hear it).

When having trouble, I will route specific information to the LEDs in
such a way that the LEDs aren't flashing at 10 kHz but rather are stead
state so I can see and "read" them.  This can be somewhat tedious as I
move through the code, but the points where I put code to write to LEDs
are intended to indicate - "This is definately working" or "this is
definately not working" and work from that.

You need to be as much of an engineer about designing temporary
diagnostic features (such as using LEDs) as you are about designing
your synth, special effect, noisemaker or whatever.

If your device has a UART, then that can be used to spray out numbers
or whatever.  Connecting to a PC COM port with a terminal program
running allows you to see them.

Bottom line is that you need to be clever regarding what you have at
your disposal and learn to code with those attributes.

It is wise to do some hello-world stuff with those things so that you
can apply them with confidence in a malfunctioning design.

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
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-- When the going gets tough, the tough use the command line.