Stephen wrote:
>
> I have looked through some of the Inexpensive Serial PIC Programmers yet most do nod adhere to the RS232 Standard very well or can have some problems. Basing my designs on the Ponyprog programmer http://www.lancos.com/prog.html and the JDM (ludipipo) http://www.ic-prog.com/jdmprog.gif programmers I have added some enhancements including an external power source, a 7805 for chip power, a LM317 or similar regulator for 13v VPP and a Maxim DS229.
> The Maxim DS229 provides RS232 signal levels. (a MAX232 or similar might work, but
> There are some flaws in the design with the VPP enable (there is a voltage drop accross R5) so I need that part redesigned.
>
> I have built the circuit and tested it, but it won't work! I have tried using IC-prog www.ic-prog.com and the voltages show up, but I fail on read and verify.
> Here is the circuit:
> http://qwertys.hypermart.net/Mypic.png
>
> -Steve
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.

Some C series chips draw a significant VPP current when programming
~50mA from memory. Having a 1K resistor in series with this current (R5)
is going to cause trouble.



--
Best regards

Tony

mICros
http://www.bubblesoftonline.com
mailto:sales@bubblesoftonline.com

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