PIC12F675 code doesnt work

[Flyback]

Hello

Do you know why this C code for PIC12F675 doesn’t work?

Its using XC8 C

All it does is make GP0 = 0 if the ADC reads the ‘busvoltage’ variable as being greater than 0x19. If the ‘busvoltage’ variable is less than 0x19 then it should make GP0 = 1;


However, it does not work.

I think its the ADC function doADC(); ...but i am not sure.


When i don’t call the doADC function i have got it able to oscillate the GP0 output. (but i don’t want the code to do that, we want the code to read ADC and act accordingly.)

//Main for the crammed long PCB

//Each Buckboost has a PIC12F675 to control it.


// PIC12F675 Configuration Bit Settings
// 'C' source line config statements

// CONFIG
#pragma config FOSC = INTRCIO // Oscillator Selection bits (INTOSC oscillator: I/O function on GP4/OSC2/CLKOUT pin, I/O function on GP5/OSC1/CLKIN)
#pragma config WDTE = OFF // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF // Power-Up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF // GP3/MCLR pin function select (GP3/MCLR pin function is digital I/O, MCLR internally tied to VDD)
#pragma config BOREN = OFF // Brown-out Detect Enable bit (BOD disabled)
#pragma config CP = OFF // Code Protection bit (Program Memory code protection is disabled)
#pragma config CPD = OFF // Data Code Protection bit (Data memory code protection is disabled)

// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.

#include <xc.h>
#include <stdint.h>
#include <pic12f675.h>

#define _XTAL_FREQ 4000000
//#define driversOff GP0 = 1
//#define driversOn GP0 = 0
//#define udhigh GP2 = 1
//#define udlow GP2 = 0
//#define cshigh GP5 = 1
//#define cslow GP5 = 0


uint8_t count;
uint8_t count1;
uint8_t count2;
uint8_t busvoltage;

void zeropot(void);
void decrement(void);
void increment(void);
void doADC(void);
void up5steps (void);
void up35steps (void);
void up64steps (void);

void up5steps (void) {
for (count=5; count=0; count--) {
__delay_us(100);
GP2 = 0; //UD = low
__delay_us(100);
GP2 = 1; //UD = high
__delay_us(100);
}
return;
}

void up35steps (void) {
for (count=35; count=0; count--) {
__delay_us(100);
GP2 = 0; //UD = low
__delay_us(100);
GP2 = 1; //UD = high
__delay_us(100);
}
return;
}

void up64steps (void) {
for (count=64; count=0; count--) {
__delay_us(100);
GP2 = 0; //UD = low
__delay_us(100);
GP2 = 1; //UD = high
__delay_us(100);
}
return;
}

void doADC(void) {
//Initiate ADRESH, ADRESL
busvoltage = 0x00;
ADRESL = 0x00;
__delay_us(100);
ADON = 1; //Turn on ADC module
__delay_ms(1);
GO_DONE = 1; //start conversion
while (GO_DONE) {;} //Wait for conversion to finish
__delay_us(100);
busvoltage = ADRESL;
ADON = 0; //Turn off ADC module
__delay_us(100);
return;
}

void increment(void) { //GET DIGIPOT READY FOR INCREMENT
__delay_us(100);
GP5 = 1; //CS HIGH
__delay_us(100);
GP2 = 0; //UD low
__delay_us(100);
GP2 = 1; //UD high
__delay_us(100);
GP5 = 0; //CS LOW ....NOW inCREMENT
__delay_us(100);
return;
}

void decrement(void) { //GET DIGIPOT READY FOR DECREMENT
__delay_us(100);
GP5 = 1; //CS HIGH
__delay_us(100);
GP2 = 1; //UD high
__delay_us(100);
GP2 = 0; //UD low
__delay_us(100);
GP5 = 0; //CS LOW ....NOW DECREMENT
__delay_us(100);
return;
}

void zeropot(void) { //get wiper to bottom of resistor ladder, ie GND
//ZERO THE DIGI POT
__delay_us(100);
GP5 = 1; //CS HIGH
__delay_us(100);
GP2 = 1; //UD HIGH
__delay_us(100);
GP2 = 0; //UD LOW
__delay_us(100);
GP5 = 0; //CS LOW ....NOW DECREMENT
__delay_us(100);
//Now decrement 64 times
for (count = 65; count = 0; count--) {
__delay_us(100);
GP2 = 1;
__delay_us(100);
GP2 = 0;
__delay_us(100);
} //Now wiper is at the bottom.
return;
}



void main(void) {
//Setup ports
//GP0 = OP SHUTDOWN; High is shutdown
//GP1 = OP UNUSED OUTPUT
//GP2 = OP U/D MCP4013
//GP3 = IP MCLR
//GP4/AN3 = IP ADC input from input rail
//GP5 = OP CS MCP4013

//To increment CS LOW, AFTER UD high
//To decrement CS lOW AFTER UD LOW

//HW SETUP
GP0 = 1; //SHUTDOWN
GP1 = 0; //UNUSED
GP2 = 0; //UD LOW
//GP3 = INPUT
//GP4 = ADC INPUT
GP5 = 1; //CS HIGH
TRISIO = 0x18; //ADC IN
INTCON = 0x00;
OPTION_REG = 0xD7;
CMCON = 0x07;
ADCON0 = 0x0C; //0000-1100 ADCoff_noconv; ch AN3; VREF=VDD;ADON is OFF//L just
ANSEL = 0x68; //fosc/64, AN3,

//5 second delay
for (count=1;count<=10;count++) {
__delay_ms(1);
}

GP0 = 1; //Shutdown the led drivers
zeropot();
increment();
up64steps();

GP0 = 0; //Turn on LEDs

doADC();
if (busvoltage >= 0x19) {GP0 = 1;}


while(1) {;}


/* while(1) {
GP0 = 1; //driversOff;
for (count=1;count<=10;count++) {
__delay_ms(100); }
GP0 = 0; //driversOn;
for (count=1;count<=10;count++) {
__delay_ms(100); }

} */



return;

}

 

[Pommie]

You seem to have the ADC set to left justify but only read the low byte of ADRES. This means you only read two bits.

Mike.

 

[hexreader]

for (count=35; count=0; count--) {

This looks completely wrong to me. Try...

for (count = 35 ; count > 0; count--) {

And same change for the other similar functions.

 

[Pommie]

You also need to check CS. In zeropot you leave it low and dont set it high in your various other routines.

Mike.