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<TITLE>RE: My Midi controlled VCF module</TITLE>
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<P><FONT SIZE=2>> Hallo!</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Your idea sounds very nice!</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> >I will use an Atmel AT89C52 microcontroller, with an AD7945 </FONT>
<BR><FONT SIZE=2>> 12 bit DAC that is also </FONT>
<BR><FONT SIZE=2>> >used for AD for the pots. (SAR principle). The uC >has 8K </FONT>
<BR><FONT SIZE=2>> flash memory, and needs </FONT>
<BR><FONT SIZE=2>> >no support logic.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> I would recommend to use the 89S8252 as this part is easy to </FONT>
<BR><FONT SIZE=2>> upgrade inside your </FONT>
<BR><FONT SIZE=2>> circuit and is easy to program even without a special </FONT>
<BR><FONT SIZE=2>> programmer by the means of the </FONT>
<BR><FONT SIZE=2>> parallel port of a PC. Another advantage is that this part </FONT>
<BR><FONT SIZE=2>> also has 2kB EEPROM inside</FONT>
<BR><FONT SIZE=2>> so the selected MIDI-receive channel can be stored and also </FONT>
<BR><FONT SIZE=2>> the last settings if you want.</FONT>
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<P><FONT SIZE=2>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).</FONT></P>
<P><FONT SIZE=2>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.</FONT></P>
<P><FONT SIZE=2>I have a programmer that can handle both, so I will give both chips a try.</FONT>
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<P><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Which programming language will you use? PLM, C, PASCAL, ASSEMBLER?</FONT>
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<P><FONT SIZE=2>I've made my prelimiary code in C, Keil C to be exact.</FONT>
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