c - 无法让 PWM 在 PIC16F877 (PICC) 上工作

Question

我一直在尝试在 PIC16F877 MCU 上使用 PWM 模块，但我得到的只是 CCP1/CCP2 引脚上的平坦低电平。

配置和启动 PWM 模块的代码如下。

// Configure PWM
// Timer 2 (PWM timebase)
TMR2 = 0;    //Clear timer
TOUTPS0 = 0;
TOUTPS1 = 0;
TOUTPS2 = 0;
TOUTPS3 = 1; //Postscaler -> 8 (previously set to 0)
T2CKPS0 = 0;
T2CKPS1 = 1; //Prescaler -> 16
TMR2IF  = 0;
TMR2IE  = 1; //Interrupt
PR2 = 233;   //~2.5ms

//PWM1 config
CCPR1L = 0x0F;
CCP1X = 0;
CCP1Y = 0; //PWM1 duty cycle 
TRISB2 = 0;  //CCP1 pin is output (Error is here, see below)
TMR2ON = 1;  //Enable timer 
CCP1CON = 0x0c; //CPP1 is a PWM

任何可以在 pic16 设备上成功启动 PWM 的代码 (PICC) 都会很有用。

Answer 1

CCP1 引脚未正确设置。“TRISB2 = 0”应该是“TRISC2 = 0”

// Timer 2 (PWM timebase)
TMR2 = 0;    //Clear timer
TOUTPS0 = 0;
TOUTPS1 = 0;
TOUTPS2 = 0;
TOUTPS3 = 1; //Postscaler -> 8
T2CKPS0 = 0;
T2CKPS1 = 1; //Prescaler -> 16
TMR2IF  = 0;
TMR2IE  = 1; //Interrupt
PR2 = 233;   //~2.5ms

//PWM1 config
CCPR1L = 0xFF;
CCP1X = 1;
CCP1Y = 1; //PWM1 duty cycle 
TRISC2 = 0; //Previously was TRISB2
TMR2ON = 1;
CCP1CON = 0x0c; //CPP1 is a PWM