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jholden
Joined: 04 Nov 2007
Posts: 2
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| setting 18f8722 to all digital |
 Posted: Mon Nov 05, 2007 1:58 pm |
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This is my first time using the 18f8722 and I am having trouble setting a few pins for digital I/O.
I am running the PIC at 5 volts.
when running the code below the pins RG0, RG3, RG4, RE4, RJ5 all spike to 1.6-2.3 volts then decay to ground in about 1ms. All other pins function correctly.
I read elsewhere that this PIC has a rather large amount of registers that need to be set to use digital IO.
I'm using compiler version 3.222 which may be the problem but it does have the 18f8722 header file so I would assume it would support this PIC
In case you're wondering this program isn't the purpose of the PIC it was simply to test the soldering connections. I soldered a second PIC to rule out any soldering damage both PICs behave the same.
| Code: |
#include <18F8722.h>
#fuses INTRC,NOPUT,NOLVP,NOBROWNOUT,NOPROTECT,NOWDT
#use delay (clock=4000000)
//disable intterupts,CCP,ADC,timers, and PSP
SETUP_CCP1(CCP_OFF);
SETUP_CCP2(CCP_OFF);
SETUP_CCP3(CCP_OFF);
SETUP_CCP4(CCP_OFF);
SETUP_CCP5(CCP_OFF);
DISABLE_INTERRUPTS(GLOBAL);
DISABLE_INTERRUPTS(INT_RTCC);
DISABLE_INTERRUPTS(INT_TIMER0);
DISABLE_INTERRUPTS(INT_TIMER1);
DISABLE_INTERRUPTS(INT_TIMER2);
DISABLE_INTERRUPTS(INT_TIMER3);
DISABLE_INTERRUPTS(INT_EXT);
DISABLE_INTERRUPTS(INT_EXT1);
DISABLE_INTERRUPTS(INT_EXT2);
DISABLE_INTERRUPTS(INT_EXT3);
DISABLE_INTERRUPTS(INT_RB);
DISABLE_INTERRUPTS(INT_PSP);
DISABLE_INTERRUPTS(INT_AD);
DISABLE_INTERRUPTS(INT_RDA);
DISABLE_INTERRUPTS(INT_TBE);
DISABLE_INTERRUPTS(INT_SSP);
DISABLE_INTERRUPTS(INT_CCP1);
DISABLE_INTERRUPTS(INT_CCP2);
DISABLE_INTERRUPTS(INT_BUSCOL);
DISABLE_INTERRUPTS(INT_LOWVOLT);
DISABLE_INTERRUPTS(INT_COMP);
DISABLE_INTERRUPTS(INT_EEPROM);
DISABLE_INTERRUPTS(INT_RDA2);
DISABLE_INTERRUPTS(INT_TBE2);
DISABLE_INTERRUPTS(INT_TIMER4);
DISABLE_INTERRUPTS(INT_CCP3);
DISABLE_INTERRUPTS(INT_CCP4);
DISABLE_INTERRUPTS(INT_CCP5);
DISABLE_INTERRUPTS(INT_OSCF);
SETUP_ADC( ADC_OFF );
SETUP_ADC_PORTS(NO_ANALOGS);
SETUP_PSP(DISABLED);
SETUP_TIMER_0(RTCC_OFF);
SETUP_TIMER_1(T1_DISABLED);
SETUP_TIMER_2(T2_DISABLED);
SETUP_TIMER_3(T3_DISABLED);
SETUP_TIMER_4(T4_DISABLED);
void main()
{
int ryt;
int rit,rot,rpt;
rit = 31780;
while(1)
{
output_A(0x00);
output_B(0x00);
output_C(0x00);
output_D(0x00);
output_E(0x00);
output_F(0x00);
output_H(0x00);
output_J(0x00);
delay_ms(500);
output_A(0xFF);
output_B(0xFF);
output_C(0xFF);
output_D(0xFF);
output_E(0xFF);
output_F(0xFF);
output_H(0xFF);
output_J(0xFF);
delay_ms(500);
}
}
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Nov 05, 2007 2:10 pm |
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1. You don't need those statements to disable interrupts. They are all
disabled upon power-on reset anyway. Those statements just clutter up
your program. Same thing for the CCP modules.
2. See this post about disabling the External Memory Interface.
http://www.ccsinfo.com/forum/viewtopic.php?t=23622
3. There are no lines in your program to toggle the Port G pins. |
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jholden
Joined: 04 Nov 2007
Posts: 2
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| Posted: Mon Nov 05, 2007 7:42 pm |
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| Thanks, but I still can't get Pin E4 to function as a digital IO. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Tue Nov 06, 2007 3:05 am |
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| Code: | int rit,rot,rpt;
rit = 31780; |
Note that in the CCS compiler the integers have an 8 bit size by default, the value of 31780 doesn't fit. In order to avoid errors like this it is good practice to use the variable types int8, int16, int32, etc., this make your program also easier to port to another compiler.
Then there is a combination of two bugs:
1) All your program code _must_ be included inside a function, i.e. the CCP, timer and interrupt functions can not be placed in the 'open' like you have now. Check the list file (*.lst) and you will see no code is generated for these lines.
2) The compiler not complaining about (1) is a compiler bug.
Having moved your initialisation code into the main function I got an error for | Code: | | SETUP_PSP(DISABLED); |
DISABLED is unknown and is to be replaced by PSP_DISABLED.
Timer2 and 4 setup contain a syntax error, there are missing parameters.
Not tested, but at least an improvement: | Code: | #include <18F8722.h>
#fuses INTRC,NOPUT,NOLVP,NOBROWNOUT,NOPROTECT,NOWDT
#use delay (clock=4000000)
#byte MEMCON = 0xF9C
#bit EBDIS_BIT = MEMCON.7
void main()
{
EBDIS_BIT = 1; // Disable external memory interface
// disable interupts,CCP,ADC,timers, and PSP
SETUP_CCP1(CCP_OFF);
SETUP_CCP2(CCP_OFF);
SETUP_CCP3(CCP_OFF);
SETUP_CCP4(CCP_OFF);
SETUP_CCP5(CCP_OFF);
DISABLE_INTERRUPTS(GLOBAL);
SETUP_ADC( ADC_OFF );
SETUP_ADC_PORTS(NO_ANALOGS);
SETUP_PSP(PSP_DISABLED);
SETUP_TIMER_0(RTCC_OFF);
SETUP_TIMER_1(T1_DISABLED);
SETUP_TIMER_2(T2_DISABLED,0,1);
SETUP_TIMER_3(T3_DISABLED);
SETUP_TIMER_4(T4_DISABLED,0,1);
while(1)
{
output_A(0x00);
output_B(0x00);
output_C(0x00);
output_D(0x00);
output_E(0x00);
output_F(0x00);
output_G(0x00);
output_H(0x00);
output_J(0x00);
delay_ms(500);
output_A(0xFF);
output_B(0xFF);
output_C(0xFF);
output_D(0xFF);
output_E(0xFF);
output_F(0xFF);
output_G(0xFF);
output_H(0xFF);
output_J(0xFF);
delay_ms(500);
}
} |
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