now swimming in standard JDM issues

[defred]

Hi all, I mounted a JDM module to burn the boostrap loader once for all in several 18F452 that I own. Guess what ? the 0000h stuff came to me. Amazing.

So I checked the whole circuit several times, read all the JDM related posts here, read the "ever the same" check  advices people gave, read also the weirds solution to specific problem.

The voltages I measure are correct. I've been doing and re-doing the whole procedure found in the JDM page. The circuit seems fine, solders ok, the 10k pulldown is "18f connected", icprog tried with various setting according to advices, screenshoot, clues...

Still no success. the whole thing is done under w98, tried on XP (with drivers ok, etc, etc), the same.

So I decided that I could have burnt the transistors while soldering. Replaced it carefully. nothing.

now a specific question : icprog seems to read the pic (but it seems also to read something when nothing is connected on the port !!), I get a load of zeros, is that the normal behavior or should I get only "FFFF"s like a blank buffer ? also should I "play" with the invert options ?

I'm not in a hurry, but I'm damn impatient for that thing to work to keep on building my box !!!

I know about all the vital checks to do, I guess I'm looking for a magical formulae.

Might the wizards show me the path ?

defred

[TK.]

So far as I remember you should read FFFF on a blank chip. But this can change from time to time, it depends on the flash process which is used on silicon.

The invert options won't help, the JDM works only with non-inverted signals.

What you could do: check the voltages during the burning procedure with a multimeter. Don't use a scope or any grounded instrument for this, because this will result to a short circuit.

Best Regards, Thorsten.

[pay_c]

Also a possible solution: Try the other serial connector on your PC (if you have two), JDM seems to work only with the first one.

[defred]

well,  thanx wizards ! Even TK the Grey came to support !  ;)

here are the readings I get from the JDM for now :

jdm standards test :

Mclr = 13.5 V

vcc = 5.2 V

clock = 4.9 V (peak)

data out = 4.7 V

during reading :

mclr = 13.5 V

vdd = 5.1 V

during programming

MCLR = 13.4 V

vdd = 5 V

It looked acceptable to me regarding the JDM page and posts on the forum. But not to my machine.

I've disabled one of my com port to be sure, but I'm not certain wether its the "hardware first" com port, I'll check that out.

New various questions :

Is that easy to destroy a pic using the JDM and a PC ?  ;D

Is that easy to check that a PIC is destroy ?  :-/

Does the "sample chip" from Microchip is really the same than the 9 euro one ?  :P

In the JDM page there's a quote about the Icprog hardware check : data in box enabling by itself when data out is enabled, is that bad if the data in box never toggles during my tests ?

Also a mysterious doubt in my blurry mind about the geometry of the bc347b, to be sure once for all : when facing the flat face of the transistor I got from left to right the collector(1), the base(2), the emitter(3) ?

To clear things up I'm burning several pic for the future projects I want to do with this hardware plateform. Also going to build right after mine, a midi box for my friend Vj that plays arkaos on stage with me. (And I was quite sure to destroy at least one)

Well thank you all anyway for your help and your marvellous MidiNerding activity.

defred

(I'm positive about cables, components seems ok, circuit seem ok checked many times but being resoldered here and there, it's a case pc...all looks fine... sniff sniff)

[defred]

I'm still confused about that "code protect" feature.

What I think I've understood is that the 10K pulldown that goes from Vss to RB5 (18F PICs) is here to disable this protection. Am I wrong ?

The LVP features and the code protect are the same ?

I read in some post that people "simply" turn off code protection, where/how can I simply do the same ?

thanks, I keep checking... but I think I'll soon try to find a MB fan here in france to burn my PICs... (hate to be delayed in my project, especially this one ! :)

defred, full of hope.

[TK.]

Hi Defred,

• no, it isn't so easy to destroy a PIC. I've (unintentionally! ;-) ) tortured it several times with Vdd > 10V or with shorts at the IO pins, but all of my PICs are still working. Thats one of the reason why I still prefer this chip in a hobbyist project :)
  
• I cannot give you a tip how to check if a PIC is working or not, since I don't own a damaged one. ;-)
  
• You will notice no difference between a sample and a purchased PIC
  
• "is that bad if the data in box never toggles during my tests": YES! This must be the error in your JDM circuit - check the signal paths between DTR/CTS and RTS. Check also your serial cable to the PC
  
• the pull up doesn't disable the code protection, but the LVP = low voltage programming mode. The JDM won't work in this mode, therefore the pull-up is required
  
• code protection is something completely different. It's just a flag in the config sector which has to be "burned" into the PIC. The flag is disabled in the .hex file of the bootstrap loader, so no reason to take care about it.
  
• however, if this would be the reason (but it isn't!), you could reset the code protection with the "blank" command
  

Best Regards, Thorsten.

FAQMARKER - since I don't want to repeat this info again and again ;-)

[defred]

okay, thanks for your time Thorsten, I'll be loosing it up a bit for the "foie gras" time.

I'll get back for a more conscious check of this JDM after Christmas.

So thanks, and merry christmas !!

defred

[defred]

PICs under groove contdition !!!  :D :D :D

Thanks a lot for the leads Thorsten, I couldn't wait so I tried at my father's house, changed the cable, under XP with icprog+correct driver = Successfully verified, Reading ok.

I might have missed something in my various cable test.

"Morale de cette histoire" : I'm not soldering that bad !

So happy Chrismas time, bring out the champaign !!!!!!! and a lot of thanks to all for the support, Im beggining to feel home in this community. Will post project bitmap soon.

Fiestas ! Chicas ! Y mas que todo MUSICA !!!!!!!!!!!

defred

[TK.]

gr@s! :-)

Best Regards, Thorsten.