JDM type programmer problem...

[bearpawz]

Well, the reason Im not entertaining purchasing another programmer is because Ive got a non existant budget right now. not for at least a few weeks... just started a new job after several months of unemployment...

Anyway, Here is the issue with the programmer:

Its constantly applying the +5 and ground, so once I have code in there that uses the internal oscilator it begins to run the code BEFORE the high voltage reaches the MCLR pin to enter programming mode. Here is what I have found with my meter hooked up in place of a pic...


When not trying to program:

VDD (pin 14) = ±5V
VSS (Pin 5) = 0V
MCLR (pin 4) = ±0V

Once I fire up programmer:

VDD = ±5V
VSS = ±0V
MCLR = ±13V

[Archangel]

Mr. bearpawz,
I do not know if you are looking for a long term solution, but why not sever the connection to the 5v terminal amd add a 5v regulator driven off the 13v line, would that work for you?

[mvs_sarma]

Well, the reason Im not entertaining purchasing another programmer is because Ive got a non existant budget right now. not for at least a few weeks... just started a new job after several months of unemployment...

Anyway, Here is the issue with the programmer:

Its constantly applying the +5 and ground, so once I have code in there that uses the internal oscilator it begins to run the code BEFORE the high voltage reaches the MCLR pin to enter programming mode. Here is what I have found with my meter hooked up in place of a pic...


When not trying to program:

VDD (pin 14) = ±5V
VSS (Pin 5) = 0V
MCLR (pin 4) = ±0V

Once I fire up programmer:

VDD = ±5V
VSS = ±0V
MCLR = ±13V

Oh!

fine readings Bearpawz,

i beleive a principle ,that one shold not purchase an nitem just cauz he /she has money-- we can use it for other purposes. likewise when we can use our knowledge and debug the faulty situation, why not -- every issue is an oppertunity from where we can gain experience. thus, you are right not to prchase-- even if you were in continuous emplyment. afterall there are thousands of users working on JDM versions.

coming to the point, can you post the schematic of your prog if your user manual has it? otherwise a dirct photo of the equipmrnt in .jpg form. it will help us to sort out the issue

[malc-c]

Its constantly applying the +5 and ground, so once I have code in there that uses the internal oscilator it begins to run the code BEFORE the high voltage reaches the MCLR pin to enter programming mode.

This is a common problem with some verions of the JDM programmer. There is a fix that is shown below.



Full details of this modification can be found at http://users.tpg.com.au/btkelly/jdm_b.htm

Another version can be found at http://www.janson-soft.de/pic/pic.htm

I use a commercial version of the JDM programmer from Olimex



which is based on the following schematic



Hope this helps

[bearpawz]

here is a picture of the programmer.. At least I think.. not quite sure how to insert a picture into this here message board so its attached...


It also seems that after playing around with the settings in IC-PROG I got it to work again. It seems like as long as I dont have to reboot Im ok. Just a couple of chips will not erase and they are probably blown or something.

[mvs_sarma]

here is a picture of the programmer.. At least I think.. not quite sure how to insert a picture into this here message board so its attached...


It also seems that after playing around with the settings in IC-PROG I got it to work again. It seems like as long as I dont have to reboot Im ok. Just a couple of chips will not erase and they are probably blown or something.

Hi Bearpawz,

That is comfortable. Doon't suspect the chips . they will also work. indicate their numbers.

next, in the user manual( if given) do you have the schematic? if so you may take a digital photo of that in a document mode with camerA SET TO LOWEST mPIXEL POSSIBLE. and save it in PC as prog.jpg
Keep a file copy ready at a known folder for uplinking. (say desk top)

now you know how to post it. ensure that the jpg is minimized by using 'stretch/skew of PAINT' in windows. there may be other methods.

[ardhuru]

Its constantly applying the +5 and ground, so once I have code in there that uses the internal oscilator it begins to run the code BEFORE the high voltage reaches the MCLR pin to enter programming mode.

While this is true, my parallel port based EPIC compatible has only 4 wires of ICSP (Gnd, Vpp, clock and data). So, when you connect it to a pic on a breadboard, the pic is constantly getting +5 volts from the target supply and the programmer has no way of controlling it. And yet, even with the internal osc. and MCLR disabled, a 12F6XX has no problems getting programmed over and over again.

I wonder how this can be explained?

Regards,

Anand

[mvs_sarma]

[QUOTE=ardhuru; While this is true, my parallel port based EPIC compatible has only 4 wires of ICSP (Gnd, Vpp, clock and data). So, when you connect it to a pic on a breadboard, the pic is constantly getting +5 volts from the target supply and the programmer has no way of controlling it. And yet, even with the internal osc. and MCLR disabled, a 12F6XX has no problems getting programmed over and over again.

I wonder how this can be explained?

Regards,

Anand[/QUOTE]

Hi Anand, EPIC and parallel port type you said. any circuit diagram for further discussion . or site where i could read a schematic please?