我使用 PIC 18 微控制器通过 PWM 控制直流电机的速度。我已经设法使用下面的代码让它旋转。我已经测试过我的H桥是100%功能的。
但是，当我打开电路时，12V 到电机，5V 到逻辑，我使用我的 RS232 通信模块向电路发送命令（我已经测试过并且它正确接收和传输），程序重置，工作台电源上的电流降至 0A。有时电机会轻微抽搐，几乎就像它试图旋转一样，但随后停止了。
有什么想法我可能出错吗？
/*
* File: serial.c
* Author: Chris Lombaard
*
* Created on September 13, 2013, 2:39 PM
*/
#pragma config FOSC = INTIO7 // Oscillator Selection bits (Internal oscillator block, CLKOUT function on OSC2)
#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)
#pragma config PWRTEN = OFF // Power-up Timer Enable bit (Power up timer disabled)
#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)
#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)
#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)
#pragma config STVREN = ON // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset)
#pragma config LVP = OFF // 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))
#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)
#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)
#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)
#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)
#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)
#pragma config EBTRB = OFF // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)
#include <P18F45K22.h>
#include <xc.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#define _XTAL_FREQ 4000000
#define length(x) (sizeof(x) / sizeof(x[0])) //Length of array
void writeUART(const unsigned char string[]);
void setup(void);
void inputCheck(void);
void stepF(void);
void stepB(void);
unsigned char buffer[8] = {' '};
unsigned char prevPos = 0;
unsigned char currPos = 0;
unsigned char bufferLength;
unsigned char direction = 0;
unsigned char speed = 0;
unsigned char isSetup = 0;
char main(void){
if(isSetup == 0){
setup();
writeUART("ERD 320 Practical 2 ----- Group 1n");
writeUART("JC Lombaard - 11028786n");
writeUART("VFDC Henriques - 11100232n");
writeUART("William Reeler - 11228866n");
writeUART("FAN POSITION: 1");
PORTDbits.RD1 = 1;
PORTDbits.RD0 = 0;
PORTCbits.RC3 = 0;
PORTCbits.RC0 = 0;
PORTAbits.RA6 = 0;
}
while(1){
if(PORTEbits.RE1 == 1)
stepB();
if(PORTEbits.RE0 == 1){
writeUART("nFan calibrated!n");
break;
}
}
bufferLength = 0;
while (1);
return (EXIT_SUCCESS);
}
void interrupt high_priority isr_high(void) {
if(PIR1bits.RC1IF == 1){
if(RCREG1 == 'n'){
buffer[bufferLength++] = ' ';
bufferLength = 0;
inputCheck();
}else{
buffer[bufferLength++] = RCREG1;
PIR1bits.RC1IF = 0;
}
}
}
void interrupt low_priority isr_low(void){
PIR1bits.TMR2IF = 0;
TMR2 = 0;
}
void inputCheck(void) {
const unsigned char commands[11][3] = {"S0", "S1", "S2", "S3", "S4", "P1", "P2", "P3", "P4", "R", "F"};
unsigned char choice = 0;
for(; choice < 11; choice++)
if (strcmp(buffer, commands[choice]) == 0){
break;
}
switch(choice){
case 0:
writeUART("FAN SPEED: 0% DC");
PORTA = 0b00111111;
speed = 0;
if(direction == 0){
CCPR1L = 0x00;
}else{
CCPR2L = 0x00;
}
break;
case 1:
writeUART("FAN SPEED: 10% DC");
PORTA = 0b00000110;
speed = 0b01101110 ;
if(direction == 0){
CCPR1L = 0b11010000 ;
__delay_ms(100);
CCPR1L = 0b01101110 ;
}else{
CCPR2L = 0b11010000 ;
__delay_ms(100);
CCPR2L = 0b01101110 ;
}
break;
case 2:
writeUART("FAN SPEED: 30% DC");
PORTA = 0b01011011;
speed = 0b10001100;
if(direction == 0){
CCPR1L = 0b11010000;
__delay_ms(100);
CCPR1L = 0b10001100;
}else{
CCPR2L = 0b11010000 ;
__delay_ms(100);
CCPR2L = 0b10001100 ;
}
break;
case 3:
writeUART("FAN SPEED: 60% DC");
PORTA = 0b01001111;
speed = 0b10101101;
if(direction == 0){
CCPR1L = 0b11010000 ;
__delay_ms(100);
CCPR1L = 0b10101101 ;
}else{
CCPR2L = 0b11010000 ;
__delay_ms(100);
CCPR2L = 0b10101101 ;
}
break;
case 4:
writeUART("FAN SPEED: 90% DC");
PORTA = 0b01100110;
speed = 0b11010000 ;
if(direction == 0){
CCPR1L = 0b11010000;
}else{
CCPR2L = 0b11010000;
}
break;
case 5:
currPos = 1;
if(prevPos > currPos){
for(int i = prevPos+1; i > currPos; i--)
stepB();
}else{
}
writeUART("FAN POSITION: 1");
PORTDbits.RD1 = 1;
PORTDbits.RD0 = 0;
PORTCbits.RC3 = 0;
PORTCbits.RC0 = 0;
prevPos = currPos;
break;
case 6:
prevPos = currPos;
currPos = 2;
if(prevPos > currPos){
for(int i = prevPos+1; i > currPos; i--)
stepB();
}else{
for(int i = currPos+1; i > prevPos; i--)
stepF();
}
writeUART("FAN POSITION: 2");
PORTDbits.RD1 = 0;
PORTDbits.RD0 = 1;
PORTCbits.RC3 = 0;
PORTCbits.RC0 = 0;
prevPos = currPos;
break;
case 7:
prevPos = currPos;
currPos = 3;
if(prevPos > currPos){
for(int i = prevPos+1; i > currPos; i--)
stepB();
}else{
for(int i = currPos+1; i > prevPos; i--)
stepF();
}
writeUART("FAN POSITION: 3");
PORTDbits.RD1 = 0;
PORTDbits.RD0 = 0;
PORTCbits.RC3 = 1;
PORTCbits.RC0 = 0;
prevPos = currPos;
break;
case 8:
prevPos = currPos;
currPos = 4;
if(prevPos > currPos){
for(int i = prevPos+1; i > currPos; i--)
stepB();
}else{
for(int i = currPos+1; i > prevPos; i--)
stepF();
}
writeUART("FAN POSITION: 4");
PORTDbits.RD1 = 0;
PORTDbits.RD0 = 0;
PORTCbits.RC3 = 0;
PORTCbits.RC0 = 1;
prevPos = currPos;
break;
case 9:
direction = 1;
CCP1CON = 0b00000000;
CCP2CON = 0b00111100;
CCPR2L = speed;
writeUART("FAN DIRECTION: REVERSED");
break;
case 10:
direction = 0;
CCP1CON = 0b00111100;
CCP2CON = 0b00000000;
CCPR1L = speed;
writeUART("FAN DIRECTION: FORWARD");
break;
default:
break;
}
}
void stepF(void){
for(int i = 0; i < 1; i++){
PORTB = 0b0001;
__delay_ms(100); //Delay between transitions
PORTB = 0b0010;
__delay_ms(100); //Delay between transitions
PORTB = 0b0100;
__delay_ms(100); //Delay between transitions
PORTB = 0b1000;
__delay_ms(100); //Delay between transitions
}
}
void stepB(void){
for(int i = 0; i < 1; i++){
PORTB = 0b1000;
__delay_ms(100); //Delay between transitions
PORTB = 0b0100;
__delay_ms(100); //Delay between transitions
PORTB = 0b0010;
__delay_ms(100); //Delay between transitions
PORTB = 0b0001;
__delay_ms(100); //Delay between transitions
}
}
void defaultPos(void){
PORTB = 0b1000;
__delay_ms(100); //Delay between transitions
PORTB = 0b0100;
__delay_ms(100); //Delay between transitions
PORTB = 0b0010;
__delay_ms(100); //Delay between transitions
PORTB = 0b0001;
__delay_ms(100); //Delay between transitions
}
void writeUART(const unsigned char string[]){
for(unsigned char j = 0; j < strlen(string); j++){
TXREG1 = string[j];
__delay_us(1000);
}
}
void setup(void){
isSetup = 1;
//PORTC
PORTC = 0x00;
LATC = 0x00;
TRISC = 0xC0; //Set RC6 & RC7 as inputs for EUSART
TRISCbits.RC6 = 0;
TRISCbits.RC7 = 1;
ANSELC = 0x00;
//PORTD
PORTD = 0x00;
LATD = 0x00;
TRISD = 0x00;
ANSELD = 0x00;
//PORTE
PORTE = 0x00;
LATE = 0x00;
TRISEbits.RE0 = 1;
TRISEbits.RE1 = 1;
ANSELE = 0x00;
//PORTB
PORTB = 0x00;
LATB = 0x00;
TRISB = 0x00;
ANSELB = 0x00;
PORTA = 0x00;
LATA = 0x00;
TRISA = 0x00;
ANSELA = 0x00;
//Oscillator
OSCCON = 0b01011100; //4 MHz oscillator
//EUSART
TXSTA1bits.BRGH = 1; //Highspeed baudrate
BAUDCON1bits.BRG16 = 0;
SPBRG1 = 12; //Baudrate of 19230 (FOSC = 4 MHz, BRGH = 1, BRG16 = 0)
TXSTA1bits.SYNC = 0; //Asynchronous
RCSTA1bits.SPEN = 1; //Enable rx & tx pins as serial pins
RCSTA1bits.CREN = 1; //Enable continuous reception, enable receiver
TXSTA1bits.TXEN = 1; //Enable transmitter
TXREG1 = 0x00;
RCREG1 = 0x00;
//Interrupts
RCONbits.IPEN = 1; //Enable priorities
INTCONbits.GIE_GIEH = 1; //Enable high priority interrupts
INTCONbits.PEIE_GIEL = 1; //Enable low priority interrupts
PIE1bits.TMR2IE = 1;
IPR1bits.TMR2IP = 0;
PIE1bits.RC1IE = 1; //Enable RX interrupt
PIR1bits.RC1IF = 0; //Clear interrupt flag
IPR1bits.RC1IP = 1; //High priority for RX interrupts
//PWM
PR2 = 0b11111001 ;
T2CON = 0b00000100; //1 KHz pulse frequency on CCP1 pin
CCPR1L = 0x00;
CCPR2L = 0x00;
CCP1CON = 0b00111100;
CCP2CON = 0b00000000;
TMR2 = 0;
}
一些建议，
- 示波器？
- 使用灯泡而不是直流电机进行测试，电流和电压降更小
- 这闻起来像硬件问题