f_11_8_pottst.c

PIC_Hi-Tech_C_Mike_Pearces_I2C_routines Microchi PIC_Hi-Tech C_I2C_for_EEPROM_24LC01B Code

#include "config.h"
#include "serial.c"
#include "serio.c"

void spi_setpotmtr(unsigned char c);
 
#define POTCS 4  //RB4 is select for potentiometer

void spi_setpotmtr(unsigned char c){
  bitclr(PORTB, POTCS);  // select potmtr
  SSPBUF = 0x11; // write command
  while(!SSPIF); // wait until transmitted
  SSPIF = 0;     // reset
  SSPBUF = c;    // write data
  while(!SSPIF); // wait until transmitted
  SSPIF = 0;     // reset
  bitset(PORTB, POTCS);  // deselect potmtr
}

#if defined(__18CXX)
void my_gets (char *s);
//return a string from the console
void my_gets (char *s){
 char c;
 
 do {
  c = getche();
  *s = c;
  s++;
  } while (c != '\r');
}
#endif

void main(void){
  unsigned char pv;

  // set select line for output
  bitclr(TRISB,POTCS);
  bitset(PORTB, POTCS);  // deselect pot

  serial_init(95,1); // 19200 in HSPLL mode, crystal = 7.3728 MHz

  // configure SPI port for potentiometer
  CKE = 1; // data transmitted rising edge of SCK
  CKP = 0; // clk idle is low
  bitclr(TRISC,3);  //SCK, output
  bitclr(TRISC,5);  // SDO, output
  bitset(TRISC,4);  // SDI pin is input, unused

  // SPI Master Mode FOSC/16
  SSPM3 = 0;  SSPM2 = 0; SSPM1 = 0;  SSPM0 = 1;
  SSPEN = 0; // reset Sync Serial port
  SSPEN = 1; // enable Sync Serial port
  SSPIF = 0;  // clear SPIF bit
  pcrlf();  printf("Potentiometer test started");  pcrlf();

  while(1) {
    printf("Input value (0-255): ");
#if defined(HI_TECH_C)	
    scanf("%d", &pv);
#endif
#if defined(__18CXX)
    {// MCC18 does not have scanf, just get string from console, use atoi
	  char buf[30];
	  my_gets(buf);  // get a string from console
	  pv = atoi(buf);  // convert string to integer
	}
#endif
    pcrlf();
    printf("Sending %d to pot.",pv);
    pcrlf();
    spi_setpotmtr(pv);
  }
}