problems with USB programmer
Long story, but in a nutshell:
Browsing e-bay I noticed a guy selling a USB PIC Programmer in kit form. He also stated that he could sell just the pre-programmed PIC and PCB's - so I e-mailed him for further details and it transpires that the programmer is in essence a GTP-USB-lite, but with his own PCB design. As I already had the files, including the HEX and drivers for this project I simply ended up purchasing the bare PCB.
I've since constructed the programmer which, from component identification is based on the attached schematic (only differences are that he uses two LEDs rather than a bi-colour LED, the trannys are BC547's, and the timing caps are 22pf not 15pf as shown). Now comes the strange part.
I hooked up the USB cable, the red LED (RB7) lit up and then went out as the green one (RB6) came on and windows found the new hardware, and on pointing it to the supplied drivers the installation was complete. It's listed in Device manager and there are no conflicts. So far so good !
I then hooked up a 16F84a and connected the ISCP leads via a jumper cable. Launched the version of winpic800 (3.55g) that came with the files and selected the detect device - bingo it came back with "16F84A" - performed a hardware check and it found the programmer and reported all was OK. - Excellent I thought all seems to be working fine.....
I then opened some hex for the target PIC and clicked on the program all button. It squirted the hex to the PIC so fast I hardly saw the progression bar (well its USB2 full speed device) - however it then got to 93% in varification and halted with an error - "No is answer of hardware" (the author is Spanish). From then on any attempt to communicate with the programmer results in the software not being able to open the driver, and I have to un-plug and re-plug in the programmer to reset it all.
So I checked the voltages:
Under normal conditions they are:
Vpp - + 0.01v
Vdd - +5.01v
data - +0.03v
clk - +0.02v
Programing:
Vpp - +13.88v
Vdd - +5.00v
data - +1.57v
clk - +1.4v
The strange thing is that once it's errored and even if you shut down the software, the programmer still retains the programming voltages.
I've tried several pics and they all do the same.
Does anyone have any ideas - or suggestions on things to try ? The fast replies from the vendor to my previous mails seemed to of stopped now..I'm hoping its just because he's gone out for the eveing, and not that he is ignoring my requests for advice !
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