0
votes

I am learning to work with PIC and I am trying to set up a PWM using CCP for PIC 18F45K22.

I follow steps as given in section 14.3.2 in the datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/40001412G.pdf . I calculated period for 8MHz FOSC and 5000Hz Fpwm.

My output remains low all the time. Any help as to what I might be doing wrong?

My code:

#if defined(__XC)
    #include <xc.h>        /* XC8 General Include File */
#elif defined(HI_TECH_C)
    #include <htc.h>       /* HiTech General Include File */
#elif defined(__18CXX)
    #include <p18cxxx.h>   /* C18 General Include File */
#endif

#if defined(__XC) || defined(HI_TECH_C)

#include <stdint.h>        /* For uint8_t definition */
#include <stdbool.h>       /* For true/false definition */

#endif

#include "system.h"        /* System funct/params, like osc/peripheral config */
#include "user.h"          /* User funct/params, such as InitApp */ 


void main(void)
{
    /* Configure the oscillator for the device */
    ConfigureOscillator();

    /* Initialize I/O and Peripherals for application */
    InitApp();

    /* TODO <INSERT USER APPLICATION CODE HERE> */
    
    OSCCONbits.IRCF = 0b110;     //8 MHz frequency selected
    
    TRISBbits.RB0 = 1;          // Disable CCPx pin output by setting
                                // the associated TRIS bit
    
    CCPTMRS0 = 0x00;               // Selected Timer 2 
    
    PR2 = 399;                  // PR2 register loaded with PWM period value
    
    CCP2CONbits.CCP2M3 = 1;     //CCP1CON bits configured to PWM mode
    CCP2CONbits.CCP2M2 = 1;
    
    CCP2CONbits.DC2B0 = 1;      // Load 2 LSB bits of PWM duty cycle
    CCP2CONbits.DC2B1 = 1;
    CCPR2L = 0b00011111;        // Load 8 SMB bits of PWM duty cycle
    
    
    TMR2 = 0x00;               //Clear timer 2    
    
    T2CON = 0b01000101;
    
    T2CONbits.T2CKPS = 0b00;    // 1:1 Pre-scaler
    T2CONbits.TMR2ON = 1;       //Enable timer 2
                  
    TRISBbits.RB0 = 0;          // Enable CCP output   
    
    while(1);
} 

Configuration bits:

#if defined(__XC)
    #include <xc.h>         /* XC8 General Include File */
#elif defined(HI_TECH_C)
    #include <htc.h>        /* HiTech General Include File */
#elif defined(__18CXX)
    #include <p18cxxx.h>    /* C18 General Include File */
#endif

 
// CONFIG1H
#pragma config FOSC = INTIO67   // Oscillator Selection bits (Internal oscillator block)
#pragma config PLLCFG = OFF     // 4X PLL Enable (Oscillator used directly)
#pragma config PRICLKEN = ON    // Primary clock enable bit (Primary clock is always enabled)
#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)
#pragma config IESO = OFF       // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)

// CONFIG2L
#pragma config PWRTEN = ON      // Power-up Timer Enable bit (Power up timer enabled)
#pragma config BOREN = SBORDIS  // Brown-out Reset Enable bits (Brown-out Reset enabled in hardware only (SBOREN is disabled))
#pragma config BORV = 190       // Brown Out Reset Voltage bits (VBOR set to 1.90 V nominal)

// CONFIG2H
#pragma config WDTEN = OFF       // Watchdog Timer Enable bits (WDT is always enabled. SWDTEN bit has no effect)
#pragma config WDTPS = 32768     // Watchdog Timer Postscale Select bits (1:32768)

// CONFIG3H
#pragma config CCP2MX = PORTC1  // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1)
#pragma config PBADEN = ON      // PORTB A/D Enable bit (PORTB<5:0> pins are configured as analog input channels on Reset)
#pragma config CCP3MX = PORTB5  // P3A/CCP3 Mux bit (P3A/CCP3 input/output is multiplexed with RB5)
#pragma config HFOFST = ON      // HFINTOSC Fast Start-up (HFINTOSC output and ready status are not delayed by the oscillator stable status)
#pragma config T3CMX = PORTC0   // Timer3 Clock input mux bit (T3CKI is on RC0)
#pragma config P2BMX = PORTD2   // ECCP2 B output mux bit (P2B is on RD2)
#pragma config MCLRE = EXTMCLR  // MCLR Pin Enable bit (MCLR pin enabled, RE3 input pin disabled)

// CONFIG4L
#pragma config STVREN = ON      // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset)
#pragma config LVP = ON         // Single-Supply ICSP Enable bit (Single-Supply ICSP enabled if MCLRE is also 1)
#pragma config XINST = OFF      // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))

// CONFIG5L
#pragma config CP0 = OFF        // Code Protection Block 0 (Block 0 (000800-001FFFh) not code-protected)
#pragma config CP1 = OFF        // Code Protection Block 1 (Block 1 (002000-003FFFh) not code-protected)
#pragma config CP2 = OFF        // Code Protection Block 2 (Block 2 (004000-005FFFh) not code-protected)
#pragma config CP3 = OFF        // Code Protection Block 3 (Block 3 (006000-007FFFh) not code-protected)

// CONFIG5H
#pragma config CPB = OFF        // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected)
#pragma config CPD = OFF        // Data EEPROM Code Protection bit (Data EEPROM not code-protected)

// CONFIG6L
#pragma config WRT0 = OFF       // Write Protection Block 0 (Block 0 (000800-001FFFh) not write-protected)
#pragma config WRT1 = OFF       // Write Protection Block 1 (Block 1 (002000-003FFFh) not write-protected)
#pragma config WRT2 = OFF       // Write Protection Block 2 (Block 2 (004000-005FFFh) not write-protected)
#pragma config WRT3 = OFF       // Write Protection Block 3 (Block 3 (006000-007FFFh) not write-protected)

// CONFIG6H
#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected)
#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)
#pragma config WRTD = OFF       // Data EEPROM Write Protection bit (Data EEPROM not write-protected)

// CONFIG7L
#pragma config EBTR0 = OFF      // Table Read Protection Block 0 (Block 0 (000800-001FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR1 = OFF      // Table Read Protection Block 1 (Block 1 (002000-003FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR2 = OFF      // Table Read Protection Block 2 (Block 2 (004000-005FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR3 = OFF      // Table Read Protection Block 3 (Block 3 (006000-007FFFh) not protected from table reads executed in other blocks)

// CONFIG7H
#pragma config EBTRB = OFF      // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)
1

1 Answers

0
votes

Fixed it - RB0 doesn't accept CCP2. Needed to change the pin to RC1