Internal oscillator with PIC18f4520

[globalsys]

Hi gents,
I'm using a PIC18f4520 with an external oscillator of 7.32Mhz, i would like to replace it with the internal 8Mhz oscillator.
I don't know how to enable the internal oscillator and disable the external.

I don't know which Fuse use on my header file.
I'm using CCS complier 3.249

Thanks
Bruno

[PCM programmer]

Look at the list of fuses near the top of the 18F4520.h file.
The internal oscillator fuses have "INT" at the beginning.

[globalsys]

Hi, it's working i use the following fuses :
#FUSES INTRC

and the this function : setup_oscillator( OSC_8MHZ );

it's working when programming with MPlab, but i'm using tiny bootloader to program the PIc trough the serial port, and it's not working due to the configuration bits of the bootloader software, and i can't change them.

Thanks
Bruno

[Ttelmah]

I'm afraid there is no answer then.
Though the oscillator can be changed once the chip is running. The chip must actually start running, and get to the line where the oscillator changes. If the bootloader has got (for example) HS selected, then the chip won't start, unless there is a crystal (or similar resonator) present on the pins. If the bootloader is set up to use an external resonator, then one has to be there....

Best Wishes

[globalsys]

Ok, maybe on my application use a bootloader is not a so good idea.
Thanks
Bruno

[globalsys]

I have another problem, on my Pin A7 i have 2Mhz clock, and i want to use this pin has an output.
Do i need to change my #FUSES INTRC ?
Or add another one?

thanks
Bruno

[Ttelmah]

Er. I hope you mean RA6, not RA7. The behaviour of INTRC, is normal port operation on RA7, Fosc/4 out on RA6. RA7, should not have a clock on it, unless there is a connection on the board, linking the signal from RA6 to it...
INTRC_IO, gives port operation on both RA6, and RA7, but if you are seeing a signal on RA7, you need to work out how it is getting there first...

Best Wishes

[globalsys]

Hi gents, I finally find a good bootloader for my PIC, without oscillator the software is working fine. But I don't know why, I'm using a display, and when I connect the display the PIC is not starting...
Can someone check my Pic configuration and tell me if there is something strange?

[nicorosen]

Hi globalsys, i read your posts and i'm not even close to your problems.
I'm also using a PIC18F4520, but the very first problem that i have, is that i can't get the CCS to compile the bootloader program. I would like if you could help me, by sharing your CCS code of the program of the bootloader for PIC18F4520, that worked for you.
I would really appreciate your help!
Thank you very much,

Nicolas

PD: for INTERNAL OSCILLATOR, i use the following lines:

#FUSES INTRC_IO //RA6, RA7 --> Normal I/O ports
#USE delay(internal=32mhz)