My Midi controlled VCF module

Jeroen Proveniers J.Proveniers at
Wed Aug 2 16:15:09 CEST 2000

> Hallo!
> Your idea sounds very nice!
> >I will use an Atmel AT89C52 microcontroller, with an AD7945 
> 12 bit DAC that is also 
> >used for AD for the pots. (SAR principle). The uC >has 8K 
> flash memory, and needs 
> >no support logic.
> I would recommend to use the 89S8252 as this part is easy to 
> upgrade inside your 
> circuit and is easy to program even without a special 
> programmer by the means of the 
> parallel port of a PC. Another advantage is that this part 
> also has 2kB EEPROM inside
> so the selected MIDI-receive channel can be stored and also 
> the last settings if you want.

Yes, but the AT89S8252 is twice as expensive! I'm also considering an AVR
AT90S4414, which costs the same as the AT89C52, but has 256 bytes of E2PROM,
and is much much faster (almost 1 million instructions per MHz; that's 12
times faster than an 8031).

The only problem is that I have to program in assembly, but the benefits can
justify this easily. I can increase the sampling frequency to 1KHz for
example, which is now a bare 100Hz.
I have a programmer that can handle both, so I will give both chips a try.

> Which programming language will you use? PLM, C, PASCAL, ASSEMBLER?

I've made my prelimiary code in C, Keil C to be exact.
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