PIC16f877 being detected as PIC16f84 in pic burner

Testing/Troubleshooting
1

Hey,

The subject is pretty descriptive as to what my problem is. 

This is the first pic I’ve ever tried to program and I also have no other ones (the same or different) to test if its just the pic or something with the programmer. 

I’m using PBreenerNG as software and the burner is detected fine and all the tests work as expected. I’ve tried to set the timings down but it had no effect. The pic is always detected as a pic16f84 when it should be showing up as a pic16f877. All the voltages look fine based on other peoples troubleshooting pages but I can post any voltages anyone might think important upon request.

I’ve also disabled all printer and scanner drivers. I’m not using a cable and put a female db25 connected to wires to the board for the parallel port. The port is 100% wired correctly which is (imo) confirmed by the fact the software does pick up the programmer and a chip, just not the right one. 

I also seem to be able to erase and blank check the chip (identified as a pic16f84) which both pass with no errors. I haven’t tried writing as I figured it wouldn’t work in the best of cases.

I’m at a loss as to where to go next.

I can’t easily get another computer to try it on and no local shops carry any pics (so I’d have to wait for new ones to be mailed to me) so I’m hoping for some ideas as to what I can check!     

thanks!!!

2

So far I remember, PBrennerNG handles the PIC as a PIC16F84 whenever no ID can be read. Probably because these old chips had no ID at all.

It could be, that the MCLR# voltage is not high enough for enabling programming mode, so that the correct ID cannot be read. The error could also be somewhere between the Data IO pin (RB7) and the data out line (Pin #10 of the Sub-D plug)

Best Regards, Thorsten.

3

You first assumption was the correct one.  I had replaced what I though was a blown out b337 with what I was told was a usable replacment (by my local electronic store sales person).  Needless to say it seems to be limited the voltage at MCLR# to 8.74 volts.   

I put back in the b337 I had still sitting around (thank god I didn’t throw it out) and it works beautifully. 13.1 at MCLR# now instead of the 8! 

Not sure why I didn’t clue in to the 8 instead of 13 but sometimes you just need someone else to make you rethink your steps :slight_smile:

burning the chip as we speak, and I am a happy camper!

mucho gracies for this amazing project!  Soon as I finish this drum controller I’m working on I’m building a SID!

:slight_smile:

thanks for the help