/****************************************************************************** Title: encoder -> PWM Author: rue_mohr Date: Aug 19 2005 Software: AVR-GCC 3.3 Hardware: atmega32 ATmega32 - 40 PIN DIP LAYOUT FOR DECODER AND PWM - _______________________ ALI <- [ 1]PB0 PA0[40] [ 2]PB1 PA1[39] [ 3]PB2 PA2[38] BHI <- [ 4]PB3 PA3[37] [ 5]PB4 PA4[36] [ 6]PB5 PA5[35] [ 7]PB6 PA6[34] [ 8]PB7 PA7[33] RESET -> [ 9]RST AREF[32] <- +5V VCC 5V VCC -> [10]VCC GND[31] <- GROUND GROUND -> [11]GND AVCC[30] <- +5V VCC 16 MHZ XTAL -> [12]XTAL1 PC7[29] 16 MHZ XTAL -> [13]XTAL2 PC6[28] [14]PD0 PC5[27] [15]PD1 PC4[26] Encoder 1 -> [16]PD2 PC3[25] Encoder 2 -> [17]PD3 PC2[24] [18]PD4 PC1[23] [19]PD5 PC0[22] [20]PD6 PD7[21] -> BLI ______________________ +5V -> AHI what this should do: when you turn the encoder one way, the motor shoudl go forward, at a variable speed when you turn the encoder the other way, the motor shoudl go backward, at a variable speed center is stopped, goes up as you get away from center when it rolls over, it will suddenly switch directions *******************************************************************************/ /****************************| INCLUDGEABLES |********************************/ #include #include #include /*****************************| DEFINIATIONS |********************************/ #define Forward 1 #define Reverse 0 #define OUTPUT 1 #define INPUT 0 /*****************************| VARIDABLES |********************************/ signed int position; // note that this is signed unsigned char oldstate; // for quadrature decoding #define ERROR 0 signed char offsets[] = { /* 0000 */ 0, /* 0001 */ +1, /* 0010 */ -1, /* 0011 */ ERROR, /* 0100 */ -1, /* 0101 */ 0, /* 0110 */ ERROR, /* 0111 */ +1, /* 1000 */ +1, /* 1001 */ ERROR, /* 1010 */ 0, /* 1011 */ -1, /* 1100 */ ERROR, /* 1101 */ -1, /* 1110 */ +1, /* 1111 */ 0 }; /************************| FUNCTION DECLARATIONS |*************************/ void pwm_init ( ); void SetPWM ( uint8_t channel, uint8_t value) ; void SetDir ( uint8_t dir ); void SetSpeed ( int Speed ); void setupEncoder ( void ); void updatePos ( void ); /****************************| CODE... |***********************************/ int main (void) { long error; DDRA = (INPUT << PA0 | INPUT << PA1 |INPUT << PA2 |INPUT << PA3 |INPUT << PA4 |INPUT << PA5 |INPUT << PA6 |INPUT << PA7); DDRB = (OUTPUT << PB0 | INPUT << PB1 |INPUT << PB2 |OUTPUT << PB3 |INPUT << PB4 |INPUT << PB5 |INPUT << PB6 |INPUT << PB7); DDRC = (INPUT << PC0 | INPUT << PC1 |INPUT << PC2 |INPUT << PC3 |INPUT << PC4 |INPUT << PC5 |INPUT << PC6 |INPUT << PC7); DDRD = (INPUT << PD0 | INPUT << PD1 |INPUT << PD2 |INPUT << PD3 |INPUT << PD4 |INPUT << PD5 |INPUT << PD6 |OUTPUT << PD7); pwm_init(); setupEncoder(); sei(); while(1) { error = position; if (error > 255) error = 255; if (error < -255) error = -255; SetSpeed ( error ); } } //------------------------| FUNCTIONS |------------------------ void SetSpeed ( int Speed ) { if (Speed > 0) { SetDir( Forward ); // set direction SetPWM( 0, Speed); // set other side } else { SetDir( Reverse ); SetPWM( 0, -Speed); } } void _SetSpeed ( int Speed ) { if (Speed > 0) { SetPWM( 0, 0); // make sure one side is stopped SetDir( Forward ); // set direction SetPWM( 1, Speed); // set other side } else { SetPWM( 1, 0); SetDir( Reverse ); SetPWM( 0, -Speed); } } void SetDir ( uint8_t dir ) { if (dir == 0) { PORTB |= 0x01; TCCR0 = 0 << FOC0 | 1 << WGM00 | /* fast pwm */ 1 << COM01 | /* inverted */ 0 << COM00 | /* this bit 1 for inverted, 0 for normal */ 1 << WGM01 | /* fast pwm */ 1 << CS02 | /* prescale by 1024 */ 0 << CS01 | 1 << CS00 ; } else { PORTB &= (~0x01); TCCR0 = 0 << FOC0 | 1 << WGM00 | /* fast pwm */ 1 << COM01 | /* inverted */ 1 << COM00 | /* this bit 1 for inverted, 0 for normal */ 1 << WGM01 | /* fast pwm */ 1 << CS02 | /* prescale by 1024 */ 0 << CS01 | 1 << CS00 ; } } void SetPWM( uint8_t channel, uint8_t value) { if (channel == 0) OCR0 = value; if (channel == 1) OCR2 = value; } void pwm_init() { // clear pwm levels OCR0 = 0; OCR2 = 0; // set up WGM, clock, and mode for timer 0 TCCR0 = 0 << FOC0 | 1 << WGM00 | /* fast pwm */ 1 << COM01 | /* inverted */ 0 << COM00 | /* this bit 1 for inverted, 0 for normal */ 1 << WGM01 | /* fast pwm */ 1 << CS02 | /* prescale by 1024 */ 0 << CS01 | 1 << CS00 ; // set up WGM, clock, and mode for timer 2 TCCR2 = 0 << FOC2 | 1 << WGM20 | 1 << COM21 | 0 << COM20 | /* this bit 1 for inverted, 0 for normal */ 1 << WGM21 | 1 << CS22 | 0 << CS21 | 1 << CS20 ; } void setupEncoder() { // clear position position = 0; // we need to set up int0 and int1 to // trigger interrupts on both edges MCUCR = (1<> 2; }