JDM type programmer problem...

[bearpawz]

Hi all,

I finnaly got my JDM programmer I bought off ebay. It was listed as

"Microchip PIC JDM Programmer" for about $13.00 USD.

Got it and installed it per directions... even installed included winpic800. Didnt work AT ALL.

So I tried IC-PROG... at first it didnt work, but then it did. Worked quite well for some time then just quit again.

Is there something Im missing here or do I just have a bad programmer (or possibly bad com port).?


My IC-PROG config is:

Programmer Type: JDM
Ports: COM1
Interface: Direct I/O
I/O Delay: 20
Comunication: (All boxes are unchecked.)


It particularly seems to have a hard time with more complicated programs. I can flash the basic "Blink" progam and it works fine. The load a more complicated program, using same fuse settings and everything and get verify errors and it reads back like its a blank chip

[bearpawz]

Ok, I think I found my problem so posting it here in case anyone else ever needs it...


I guess there is an issue when you try to use this programmer after programming the config to use Internal Oscilater and no MCLR... (Both of which apply to me).

From what I found on the internet the programmer its self applies constant power to pic, so once you flash it the first time with those settings, it will just run and wont will not program.


So anyone know a down and dirty cheap way to "erase" the pic back to default?

Im using 16F818 BTW

[Archangel]

Hi Bearpawz,
I am using the exact setup you are. I use it, attached to COM2. I have found it sometimes gets reset back to com1. I find I sometimes have to erase the chip twice to program it. I have even had the situation where after erasing once, I need to fill the buffer with all zeros, program the chip and then program the chip with the hex file, it seems to erase and program normally then. The jumper on your programmer has to be moved, to switch from the smaller 18 pin to the 40 pin devices. hope this helps.
JS

[skimask]

Ok, I think I found my problem so posting it here in case anyone else ever needs it...


I guess there is an issue when you try to use this programmer after programming the config to use Internal Oscilater and no MCLR... (Both of which apply to me).

From what I found on the internet the programmer its self applies constant power to pic, so once you flash it the first time with those settings, it will just run and wont will not program.


So anyone know a down and dirty cheap way to "erase" the pic back to default?

Im using 16F818 BTW

PGM pin pulled down (or up?), don't remember which? Shouldn't matter using HV on MCLR, but you never know.

[bearpawz]

Ok, well its very clear now that this JDM programmer just is not going to erase a chip with my configuration. For the record it has no power supply... just runs off the serial port and there is some issue with it running code before the programmer can get to it so...

Instead of trying to build a whole new programmer... I would like to just sacrifice maybe one of my chips to build a down and dirty simple "bulk eraser". My thoughts are this:

Use one pin for a push button to start the whole procedure...

Once button is pushed it will activate a transistor to bring MCLR high and initiate programming mode all from the one PIC chip. So one transistor would be the only other component... the rest would just be using PIC to PIC pinout...

So now my question is... does anyone know the exact specification for bulk erasing a pic?

[skimask]

Ok, well its very clear now that this JDM programmer just is not going to erase a chip with my configuration. For the record it has no power supply... just runs off the serial port and there is some issue with it running code before the programmer can get to it so...

Instead of trying to build a whole new programmer... I would like to just sacrifice maybe one of my chips to build a down and dirty simple "bulk eraser". My thoughts are this:

Use one pin for a push button to start the whole procedure...

Once button is pushed it will activate a transistor to bring MCLR high and initiate programming mode all from the one PIC chip. So one transistor would be the only other component... the rest would just be using PIC to PIC pinout...

So now my question is... does anyone know the exact specification for bulk erasing a pic?

If you're thinking the JDM programmer is having issues with power, why not cut the trace to the power pins and add your own power?

As far as making your own bulk eraser...each different family of PICs has it's own method of talking when doing programming/erasing. So unless you are only going to use one family of PICs...ever, I don't think it's worth the time.

Why not go to Microchip's website and check out the PICKIT2? USB, upgradable, $35USD, and a good deal at that. Actually, Microchip is out of stock, but Digikey has a load of them at the same price. I've got it on good authority (thanks to mister_e) that these PICKIT2's are good programmers and I'm going to buy 2 of them very soon. My old Warp13a is over 8 years old...good programmer, but I want a new one.

[mvs_sarma]

Hi Bearpawz,

if you are using a new PC with low voltage working, the VPP is an issue. as you are not using an external power supply, try to check out what are the measured values of Vcc and VPP by suitably inverting the concerned pins theo winpic800 program. if the pin4 doen't get 13V or little above programming doent take place. also the dellay could be set to 20 instead of 10 or 15. If the eBay has provided the schematic, try to to put it on the post and it will help us disgonose what is really happening-- in all probabilities, low voltages or noice on these voltages is the reason.

eg., one maunufacturer has used MC34063A to derive Vpp from the Vcc obtined from the COM port. if you have only a charged cap as Vpp supply and the PC is of low votage(modern), then you may have to improvise it. afterall prchasing another will not assue trouble free-- we have to study and sort out the issue.

Incidentally if the programmer that you got is of FENG3 ver5.2 rev8
the designer clearly says not to connect the PC's ground to the programmer ground. please check that. if you want you can see the scmatic of FENG3 at http://hamradioindia.org/circuits/feng.php#mods


please inform developments--