Read the newbee threads, 16F877A no go.

[NavMicroSystems]

Bobby,

I guess it is a matter of setting the configuration bits.

with a 12 MHz crystal you should select HS Oscillator.
and do you have a 4k7 pullup on the MCLR Pin?

have a look at this Thread

[BobbyA]

Hi Ralph, Thanks for taking the time to respond.
I do have the pull up in, and saw Melanie's post on configuration fuses.

Her thread wasn't completely clear to me as to where those lines would be entered. The Microcode Studio doesn't provide for switches, nor did the MPASM I tried selecting within Studio.

I did see another thread on editing the .inc file, and I changed it from xt to hs in two places. Hoping that was what he had in mind.

From some other posts it appears that the configuration switches end up embedded in the .hex file. I hope this is correcct as it should be easy to read them out of the file resulting from compiling the short example program in the first msg. I just have to find out what the bits (placement) of that line is supposed to read.

I'm ok with BASIC, but trying to learn PICs and PBP.


Best Regards,
Bobby

[BobbyA]

Looking further into the configuration bits only confuses things more. From Melanie's thread on setting them up, I looked at the .inc for entries matching the datasheet's Special Features section. The datasheet calls out many configuration bit switches that are not addressed in the .inc file.
I'm really hoping these bits are not important to be set or cleared, otherwise it doesn't inspire confidence. I still have little idea on what the configuration bits should be set to. Learning more every day...

Bobby

[mister_e]

Did you read the whole thread??? I post some info myself too
here

So can we assume that something is working now on your side???

[BobbyA]

The short test program included in my first email will run now.
A number of changes were made, including editing the \PBP\xxxxxx.inc file.
Also turned off the watchdog timer, I may turn it back on to check effect.
Somewhere along the way I've hosed up the MPASM configuration and now
will have to get it working again. But hey this is a learning process right ?

Thank you for the help.
Bobby

[BobbyA]

I switched the wdt_ configuration back to on, and the toggle program still runs.
The larger program even executes, more or less.
The less part is that I'm required to press the reset button to get my program to run, where the original development board firmware executes on powerup.
Any suggestions where to start looking ?

Thanks,
Bobby

[mister_e]

ARGH, are you using some kind of bootloader??? if so add
DEFINE LOADER_USED 1

[Archangel]

The less part is that I'm required to press the reset button to get my program to run, where the original development board firmware executes on powerup.
Any suggestions where to start looking ?

Thanks,
Bobby

Hi Bobby A,
I agree with you about the books and manuals ability to convey everything a newbie needs to learn, they basicly blow! This forum is very helpful, very many smart people here!
For the problem above try putting a capacitor of say 1uf from the reset pin to ground. the time it takes to charge through the resistor you have going to B+ will allow the PIC to stabalize on start up. It seems some individual pic chips need this, I do not know why . . . maybe est damaged? Just curious are the chips you are using samples?
JS