Re: JDM PIC programmer troubleshooting
- From: byron@upstairs.(none) (Byron Jeff)
- Date: Thu, 24 May 2007 22:27:27 -0500
In article <1179084818.897901.45890@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
grubertm@xxxxxxxxx <grubertm@xxxxxxxxx> wrote:
Hello,
A while ago I came across a schematic for a slightly modified JDM PIC
programmer which I just finished building. Unfortunately using it with
IC Prog did not yield good results- even though Vdd and MCLR voltages
are present,
What are the value of those voltages?
I am only getting blank data when trying to read/write a
16F84A chip.
Another item on a 16f84a. IIRC its Vpp has to have a voltage of 13V
nominal.
* What other signals should I be checking and what are the expected
values ?
Start with Vpp and Vdd values. If Vpp isn't at least 12V it isn't going
to program.
* What are reliable settings in IC Prog ?
* Does the schematic look correct? I compared it with the original
design and noticed a 2.2k instead of 1.5k resistor and the transistors
are different, though they seem to have similar specs :
http://img218.imageshack.us/img218/633/jdmro1.png
Probably not critical. The biggest problem with the JDM programmer is
that it requires a real serial port (i.e. +/- 12V signals) to work
properly. Most modern serial ports swing at much lower voltages.
BAJ
.
- References:
- JDM PIC programmer troubleshooting
- From: grubertm@xxxxxxxxx
- JDM PIC programmer troubleshooting
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