Pickit 3 help

[diag7919]

Hi guys, wonder if anyone can help. I bought a pickit 3, installed the software in the hope I can read the contents of a 16f676 out of a field energizer. It keeps saying invalid code. So I purchased a new 16f676 and it identifies it just fine. I'm not sure what's going on. I toasted pin 2 and now the device doesn't power up, I would order another device if only I can get code out the old. I'm thinking That the read protect but is set but wouldn't the software just say the chips protected, you ain't reading it's contents or does it refuse any read requests which might explain why I keep getting this chip I'd error... Next step is to microscope it's ‼️ mgs but I was pretty sure it was a 16f676..


Bit lost

[wilfred]

Did you buy a genuine Microchip one? There are clones like a rash all over Ebay.
By coincidence I saw this video a few days ago that talks about one guys experience and it sounds similar to yours.


I bought a Pickit 3 over 10 years ago, does Microchip even still sell them? Are all PK3's clones now?

[jpanhalt]

The most likely reason is that the chip is read protected.  Microchip PIC MCU's have what they call "fuses."  When a chip is programmed, the programmer can be set to make the chip non-readable.  I do not know what error PK3 returns when facing such a chip.

If you go on the Internet, there are ways code pirates use to try to get around code protect.  I doubt that would be economically feasible for a one off. 

Such protected chips and be erased and reprogrammed in most instances, but obviously, that is not what what you are trying to do.

[Hella_Wini22]

Which software are you using ?
MC  has stopped supporting it on MPLABX some year or more ago.

MPLABX didn't nag about it or anything, just programming failed.

MC somewhat patched it but stated that from there on pPickit3 may or may not work and they aren't going to bother caring for it.

Just about a month ago they stopped caring about MPLABX mess as a whole and ported everything into VSCODE extension modules.

So now Pickit4/5 are supposed to work with VSCODE.

Actually, your problem might be two-fold:

   * support of your MPLABX for Pickit3
   * support of Pickit4/5 for your prehistoric PIC. It should work, but did anyone bother to check ? 🙄

[Ian.M]

On older 8 bit FLASH PICs, read protection simply forced the returned program memory data to all zeros (NOP).  No errors, no warnings just an unusable read!

Also on most PICs the /MCLR (Reset) pin can be disabled and used as an ordinary input pin.  If its disabled, and the PIC is using an internal oscillator and the code in the PIC set the programming pins ICSPCLK and/or ICSPDAT as outputs near the start of the code, depending on their levels, the programmer cant set the required conditions for program mode entry due to level contention, and it can fail to detect the PIC or if detected, can fail to read or reprogram any memory area.

[Postal2]

The problem is known. Pickit 3 will lock your mcu if you foolishly connected power to the target mcu when pickit was first detected (this is demonstrated in the video above).

I bought my Pickit 3 on Aliexpress in 2019 ~$10, works great. There is no sticker on the back.

[MikeK]

If you think the old PIC is code protected, then simply code protect the new PIC you bought and see what the PK3 says.

[radiolistener]

Did you buy a genuine Microchip one? There are clones like a rash all over Ebay.
By coincidence I saw this video a few days ago that talks about one guys experience and it sounds similar to yours.

I bought pickit3 from aliexpress, it looks the same as on your video. It works good.

Regarding the topic starter's issue, it looks like the MCU is protected from reading. There are some hacks that allow bypassing this protection, but I haven't used PIC MCUs in a long time, so I can't provide details. However, as mentioned above, hacking it just to clone one instance isn't worth the effort. It's easier and cheaper to buy a new device.