Problem with rewriting 12f675

Thread Starter

vane

Joined Feb 28, 2007
189
My Dad got me some PIC 12f675s and they came today. Uploaded a .HEX to one, it did work, then i put it back on the writer and went to write another version to it, now it says an error saying there is either not a PIC on the programmer board, it isn't in program mode or PIC type os mismatched with software, i am wondering whether there is a problem with erasing.

I tried another PIC and it only wrote to it once, then it gives the error, to my knowledge they are not single use PICs, i certainly didn't mean to get single use PICs.

I have the velleman K8048 programmer board if that helps.
 

Markd77

Joined Sep 7, 2009
2,806
Have a look at thread "Fighting a 12F675..." which is about 20 posts down and see if that answers your questions.
 

Thread Starter

vane

Joined Feb 28, 2007
189
Well thats just bloomin great :( the programmer i get turns out to have a quite serious bug, do you know if this works?

I recalled enough of it to remember that some people suggested holding the base of one transistor (T4) low by shorting out a diode (D7).This seemed to work - the pic was recognisable again. Some people have soldered a line in to do this at will, or added a little resistor/capacitor pair to enable VPP before VDD...
Buying a new programmer will be a 100% no no due to lack of funds :(
 
Last edited:

Thread Starter

vane

Joined Feb 28, 2007
189
99% sure it aint the code protection, it doesn't code protect my 16f84A when that is written to

Is there a configuration in picprog2 for disabling the code protection?
 

Thread Starter

vane

Joined Feb 28, 2007
189
From what i have heard i need to supply 13.5 volts to MCLR then put power to VDD to get it into programming mode :s Can anyone speculate on anything i have said?
 

Thread Starter

vane

Joined Feb 28, 2007
189
OK, i have tried doing the manual 13.5 volts to MCLR then erasing the data, now i just get errors like:

wrote: 2804
Read: 2004
 

n9352527

Joined Oct 14, 2005
1,198
I've seen this problem in many different programmers, not only Velleman. There was a guy in this thread experiencing the same problem. He was using a JDM clone. There were also reports of the same problem with Mchp ICD2 programmers. I noticed this problem first when I was working with a MatrixMultimedia dev board.

Maybe you could try the solution that I used, see in the above thread.
 
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