how to use external crystal?

[towlerg]

Deleted...........

[Dave]

tbarania, How are you loading the program into the PIC? If you are using a bootloader the " __config1 _FOSC_HS & _WDTE_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOREN_ON & _IESO_ON & _FCMEN_ON & _LVP_OFF & _WRT_OFF" statement is NOT being executed.

[richard]

I have a bunch of 20MHZ low profile xtals that are happiest with _FOSC_XT an 22pF caps , had me guessing for a bit

[tbarania]

I've tried

#config
__config1 _FOSC_HS & _WDTE_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOREN_ON & _IESO_ON & _FCMEN_ON & _LVP_OFF & _WRT_OFF
#endconfig

at the top the basic program. I compile and load the hex file into MPLAB and program the chip using the PICSTART Plus. I leave the configuration bits "set in code" since I'm assuming that is what the above is supposed to take care of. Apparently it doesn't, rather the PIC reverts to the 4MHz internal oscillator. I also set the OSCCON to %01101000 which is supposed to use bits FOSC 0-2 to set the oscillator choice.

I also tried defining the config1 register to set it up to use the external crystal: DEFINE CONFIG1 $EFC2 Maybe defining is not the right approach and I need to do some sort of assembly code snippet.

I can select the 8MHz internal oscillator by setting OSCCON, so I don't know why it won't let me select an external crystal.

[AvionicsMaster1]

I wonder if #config/#endconfig is case sensitive like DEFINE? I know to say define osc 8 won't work but DEFINE OSC 8 does.

The manual shows how to do some conditional compiles but the CONFIG item is in caps.

[Archangel]

I wonder if #config/#endconfig is case sensitive like DEFINE? I know to say define osc 8 won't work but DEFINE OSC 8 does.

The manual shows how to do some conditional compiles but the CONFIG item is in caps.

Pretty sure define OSC 8 works too

[AvionicsMaster1]

I'm sure there are many variations and I appreciate you adding one. My point was that the config statement

#config
__config1 _FOSC_HS & _WDTE_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOREN_ON & _IESO_ON & _FCMEN_ON & _LVP_OFF & _WRT_OFF
#endconfig

doesn't look like the one in the manual. There are space at the beginning of the line __config and after each & that are not in the config statement above. I realize the config statement is ASM and therefore only the fuse is case sensitive but I thought it at least worth the effort.

The manual also shows #CONFIG/#ENDCONFIG in caps. Just sayin'.

[richard]

for pbp3
#CONFIG
__config _CONFIG1, _HS_OSC & _WDT_ON & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOR_ON & _IESO_ON & _FCMEN_ON & _LVP_OFF & _DEBUG_OFF
__config _CONFIG2, _BOR40V & _WRT_OFF
#ENDCONFIG


for pbp 2.6
ASM
__config _CONFIG1, _HS_OSC & _WDT_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOR_ON & _IESO_ON & _FCMEN_ON & _LVP_OFF & _DEBUG_OFF
__config _CONFIG2, _BOR40V & _WRT_OFF
ENDASM

I tried #CONFIG/#ENDCONFIG and #config/#endconfig and both work therefore its not case sensitive


this is just wrong for a PIC16F886

#config
__config1 _FOSC_HS & _WDTE_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOREN_ON & _IESO_ON & _FCMEN_ON & _LVP_OFF & _WRT_OFF
#endconfig

ps
I'm surprised it can compile