'Making a JDM programmer useful again(?)'
I have a JDM serial port PIC programmer (made by Olimex, model
PIC-PG2, rev. C, http://www.olimex.com/dev/pic-pg2.html). Needed to
program a PIC 18F4320 (40-pin) chip, so I fired it up for the first
time in many years. Used a ThinkPad T23 to drive it, with both ICPROG
and PICPgm apps, and the special Win XP driver. Didn't work. LED
never flashed during the programming sequence.
Suspected that the serial port wasn't generating the right signals to
drive the JDM board and generate the 12v needed for Vpp input to the
PIC. Measured this voltage during programming with a DVM and it was
only 3-4 volts. Seems like this is verified by much discussion on the net.
1. Has anyone modified a JDM board to use an external power source,
e.g., batteries, to supply the requisite programming voltage? How?
2. Presuming I get it working again, which of the above two apps (or
others) do you recommend?
3. Presuming I don't get it working, what's the recommended
inexpensive(!) USB PIC programmer? PICkit2 clones (e.g., from AU Electronics)?
Note: Given that I can get a legit PICkit2 from Microchip online for
about $40 + S&H in a few days, answers that exceed that cost or
solution time aren't very useful. Or to look at it another way, this
isn't a very valuable query :-)
Palo Alto, CA
|The PICKit 2 from Microchip is the way to go. Works great and makes
programming very simple. Mine has been 100% reliable through thousands of
program cycles. The stand -alone GUI app has many nice features. The UART
tool and logic analyzer are handy features to have too.
The jury is still out on the PICKit 3. Microchip has responded to customer
comments and is makng improvements, but unless you're pushing the edge with
the latest parts that the '2 doesn't support, I'd stick with the PICKit 2.
One quirk of the PICKit 2 is that it's unhappy if the computer goes into
hibernation or sleep while its application program is open, and it locks up
the program. My solution used to require rebooting to clear it, but then I
found the easy solution is to just unplug the PICKit 2 from the computer,
close the application, re-connect and relaunch the software.
Ever since the copy protection scheme on my Olimex programmer refused to let
me upgrade, and the Olimex response was that their scheme COULD NOT make an
error, so therefore Sparkfun had probably cloned the firmware numerous times
befre selling it to me, I highly recommend against any of their
programmers. At 3x the cost of the PICKit 2, their USB programmer never did
work very smoothly. (Kudos to Sparkfun for providing an upgrade when Olimex
refused - but the programmer is gathering dust now).
On Mon, Jan 18, 2010 at 2:01 AM, Michael Wirth <gmail.com> wrote: mwirth
> Suspected that the serial port wasn't generating the right signals to
> drive the JDM board and generate the 12v needed for Vpp input to the
> PIC. Measured this voltage during programming with a DVM and it was
> only 3-4 volts. Seems like this is verified by much discussion on the net.
Yes, I made a JDM a while back and it won't run off my laptop's 0-5V
serial port (from a Dell Latitude). I used a PCI serial expansion card
in my laptop's docking station to talk to it.
> 3. Presuming I don't get it working, what's the recommended
> inexpensive(!) USB PIC programmer? PICkit2 clones (e.g., from AU Electronics)?
I wouldn't bother getting it working. The PICKit2 is a great little
device, and once you discover ICSP you will wonder how you did without
it. Some of the PICKit2 clones come unprogrammed, and require another
device to load the firmware (the firmware is available from Microchip
There is other gotcha's with the JDM that happen with programing
sequences on different PICs, like the 16F628A. Mine didn't work
without a hardware modification. Entirely not worth it.
About what I expected....
Thanks for the very informative replies, Jon and Adam. Will go with
Cheap, impatient and curmudgeonly in Palo Alto.
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