V2 Development Board with 16f877A

[JohnnysTubeAmps]

Dear Guys,

I am able to program a 16f84A no problem, but when trying to program a 16f877A i get the following message;

"The program has NOT been sent correctly (Note: if the PIC is code-protected this message will be displayed even if the program has been sent correctly)"

The Config word I am using is 3F3B, which I believe has all code protection disabled.

Is the 16f877A compatible with the V2 development board?

If it is not compatible, would I get better results with a 16f873A?

Thanks in advance for your help...

Regards,

JC

[Benj]

Hello

The 16F877A is compatible with the V2 Dev board. It could be that in a previous program you have set one or some of the write protection bits in the configuration and this has now locked you out from re-programming the device. Another alternative is that the device is damaged. Do you have a second 16F877A that you can test to make sure it is not the chip at fault.

Your config value of 3F3B looks correct for the RC oscillator with no code protection.

[JohnnysTubeAmps]

Dear ben,

Thanks for your reply. I have since tried 2 new 16f877As and a new 16f873A, all with the config word of 3F3B, and I am still getting the code protection error on all of these.

However, I can still program my 16f84A no problem. Is there anything else I can try, or do you think there is a problem with my development board?

Just to reiterate, I am using a Version 2 development board hooked up to a Win 98 computers parallel port. Using ASM:IDE to prog.

Kind Regards

JC

[JohnnysTubeAmps]

Ben, have also noticed that my unregulated 12v DC supply is giving me around 17 volts onto the development board.

I think that MCLR to Vss is somewhere around 14v max, do you think the 17 volts could be frying the chips ? (however, the 16f84A is still OK).

Thanks in advance for your help....

Regards

JC

[JohnnysTubeAmps]

HI Ben,

Sorry to keep coming back with more info. I am trying to use ASM-IDE version 1.0 . Should I be using a later version, or does it not matter?

If so, do you have a later version available?

Regards

JC

[Benj]

Hello

The unregulated supply giving 17V sounds like it may be the cause of the problem. The programming voltage should be around 12V. On our newer boards we use a 13.5V power supply to allow for a bit of a voltage drop across the bridge rectifier. Strange how it works with the 16F84 though, perhaps these chips are a little more tolerant.

There also shouldn't be any problems with you using the ASM-IDE v1. We do have newer versions but they are packaged with updated versions of the assembler course.

The only thing I can suggest is to try and sort out your supply or find another supply that will provide a nice 12V DC input.

Perhaps a new ECIO or EB006 could be the answer to your problems if you are getting back into micros again.

[Benj]

According to the datasheet the maximum voltage that can go onto the programming MCLR pin without damage is 14V. Therefore the 17V may have damaged your devices making them unusable. It might be worth just seeing if they come back to life with a workable PSU.

[JohnnysTubeAmps]

Thanks for your help Ben,

I'll try a new supply...

Regards

JC