PIC unresponsive after programming

I'm somewhat new to programming PICs but I have a very good background in z80 assembly. I've been working on a pic10f200 to be used as a mod chip in an Xbox controller. Everything was going great, I got the full-auto complete, then I got the burst mode complete, but when I went to link it all together with menus. My chip became unprogrammable.

Here is what happened. I sent my program to the pic10f200. The chip worked just like it is supposed to when I hooked it up and test it. But when I went to reprogram it, it was unresponsive. I figured that maybe it fried or something, so I grabbed another chip, programmed it and tested it. It worked fine, but again, I couldn't reprogram it. So my final test was to take another brand new chip, write the program, and then read it back. Even this test failed. So I have no idea.

Some specifics:
-pic10f200
-JDM programmer
-winPic800
-The chips can't be read from or written to
-The chip still functions even though it can't be programmed.
-The problem appears to have started when the program size exceeded 160 words (0xA8 ) or close to it. I would test this further but I'm out of chips
-I don't think that it is the code protection as that lets the first 64 byte read back while the rest are 0's. Mine are all just 3FFF's
-It is not caused by anything other than programming it

Here is the source I'm using.

Can anyone help me?

sounds like the chip continues to function. it is just that you cannot reprogram it with the jdm programmer?

is it possible that the issue is with either your programmer or your way of programming it? have you tried with a real programmer (pickit2/3 for example)?

Yes, the chip functions from the last time I programmed it. It just now is completely unrecognized by the programmer.

I haven't tried using a real programmer because I don't have one. They are a little too expensive. Is it possible that the JDM is just not doing the job.

I don't mean to sound rude, but for pete's sake, just buy a Pickit2 programmer ($35). You posted a similar problem with this programmer/microcontroller combination in March 2010. How much is your time worth? For the price of a couple of pizzas you could get rid of these headaches.

I'm all for DIY, but geez, is it really worth it if it's this frustrating? Bite the bullet and buy the programmer (you think $35 is bad, the previous generation of Microchip programmers cost $200+).

Just do it! ;-)

in my experience, the jdm programmer I have used isn't reliable at all.

I agree with Nick C that it is much cheaper to buy a more expensive pickit2.

millwood said:

in my experience, the jdm programmer I have used isn't reliable at all.

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It had its day, but the JDM design goes back to the late 90's, so it's going on 15 years old. Much has changed since the 16F84 was king, and Microchip doesn't make things any easier with all of their little programming idiosyncrasies that crop up as parts evolve.

To the OP - it's time to take the old fella out back, shoot it, and move on.

Oh, I didn't realize that the JDM sucked so bad. If I knew that I probably wouldn't have gotten it. I thought that it didn't really matter what programmer you had.

I'll have to get a pickit. I thought that they cost $200, but I didn't look that hard. If that solves my problem then all is good.

thepenguin77 said:

Oh, I didn't realize that the JDM sucked so bad. If I knew that I probably wouldn't have gotten it. I thought that it didn't really matter what programmer you had.

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The JDM was always a bit troublesome because it derived its power from the RS-232 port, and as the years went by it seems as if PC manufacturers strayed further and further away from the established RS-232 electrical specifications. I always had better luck with parallel port "Tait" programmers. I keep a generic Tait and an old MELABS one around for programming the old OTP parts that the newer programmers aren't capable of programming.

I'll have to get a pickit. I thought that they cost $200, but I didn't look that hard. If that solves my problem then all is good.

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I think that's your best bet. Now you just have to decide if you want to go with a Pickit2 or Pickit3. I don't know why Microchip has to make things so difficult.

The Pickit2 comes with neat logic and UART analyzer functions, which have been dropped in the Pickit3. However, the Pickit2 is no longer being updated for newly released microcontrollers. So you've got a decision to make. Here are a couple of videos that hopefully will help you to decide.

Any pic that requires a Vpp-before-Vdd algorithm to program, and has MCLR disabled, internal oscillator will have problems with the JDM, as JDM cannot control the Vdd.

There's a work around to this in a JDM derivative on the net, but like everyone else suggests do get a Pickit2, it will resurrect your locked chips.

Alternately, try another chip, this time with MCLR enabled (as long as you arent using this pin in your design) and see if the problem gets solved.

Regards,

Anand Dhuru

Here are a couple of videos that hopefully will help you to decide.

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the last one is funny,

yeah, I never understood what microchip was trying to do with pickit3, and their refusal to provide continued support for pickit2 (a perfect programmer in my view).

ard said:

Any pic that requires a Vpp-before-Vdd algorithm to program, and has MCLR disabled, internal oscillator will have problems with the JDM, as JDM cannot control the Vdd.

There's a work around to this in a JDM derivative on the net, but like everyone else suggests do get a Pickit2, it will resurrect your locked chips.

Alternately, try another chip, this time with MCLR enabled (as long as you arent using this pin in your design) and see if the problem gets solved.

Regards,

Anand Dhuru

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Yes, Anand, the thepenguin need to use Vpp first programming. I know of TWO JDM designs that provide for this facility.

1. Multi Pic Programmer a by FENG at www. hamradio.in,
2. DL4YHF programmer with external power supply this has facility for Vpp first.

Another main issue is that the COM port should support +/-12V supply, as it helps derive the Vpp from the said voltage. Some Modern Desk tops and many old laptop give a lower supply at COM port pins.

Thanks for showing me the difference between PICkit 2 and 3. It looks like 2 works better for my purposes. I also see a lot of benefits to it. Mostly the fact that I just got a new laptop and usb powered will make it a lot easier.

I'm sure my computer puts out the right voltage because I checked it a long time ago and it was just slightly less than 13. It is also not one of those newer desktops, it's ancient.

a pickit2/3 is the way to go, if you are already onto the pic route.

if not, there are much simpler solutions: like the stm8s discovery (<$10, available now) that provides you with a dev board, a programmer, a debugger, and some ancillary devices; the LPCxpresso ($30? that's dev board/programmer/debugger in one), or the upcoming stm32 discovery (<$10, 32-bit Cortex-M chips, programmer/dev board/debugger in one). and Luminary has a similar design as well.

in my view, investing in a PIC now does not make good sense.

millwood said:

yeah, I never understood what microchip was trying to do with pickit3, and their refusal to provide continued support for pickit2 (a perfect programmer in my view).

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It wouldn't surprise me if these missing features miraculously appear in the PICkit3 immediately after Microchip runs out of PICkit2 inventory.

Well, my picKit 2 came in the mail today. And it worked!!! Thank you so much for getting me to buy this. Now I can finally finish this project almost a year later.

And it worked!!!

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congratulations!

I have always said this: free tools are generally too expensive.