// // // hello.ftdi.44.echo.interrupt.c // // 115200 baud FTDI character echo, interrupt version // // set lfuse to 0x7E for 20 MHz xtal // // Neil Gershenfeld // 12/8/10 // // (c) Massachusetts Institute of Technology 2010 // Permission granted for experimental and personal use; // license for commercial sale available from MIT. // #include #include #include #include #define output(directions,pin) (directions |= pin) // set port direction for output #define input(directions,pin) (directions &= (~pin)) // set port direction for input #define set(port,pin) (port |= pin) // set port pin #define clear(port,pin) (port &= (~pin)) // clear port pin #define pin_test(pins,pin) (pins & pin) // test for port pin #define bit_test(byte,bit) (byte & (1 << bit)) // test for bit set #define bit_delay_time 100// with 9600 baud rate //8.5 // bit delay for 115200 with overhead #define bit_delay() _delay_us(bit_delay_time) // RS232 bit delay #define half_bit_delay() _delay_us(bit_delay_time/2) // RS232 half bit delay #define char_delay() _delay_ms(10) // char delay #define position_delay() _delay_ms(1000) #define serial_port PORTA #define serial_direction DDRA #define serial_pins PINA #define serial_pin_in (1 << PA0) #define serial_pin_out (1 << PA1) #define serial_interrupt (1 << PCIE0) #define serial_interrupt_pin (1 << PCINT0) #define bridge_port PORTA // H-bridge port #define bridge_direction DDRA // H-bridge direction #define IN1 (1 << PA2) // IN1 #define IN2 (1 << PA3) // IN2 #define PWM_direction DDRA #define PWM_port PORTA #define PWM1 (1 << PA5) #define PWM2 (1 << PA6) volatile unsigned char chr = (char)175; volatile int speedfor = 0; // 136 (w 2 pretty full 9V batteries) is lowest speed that will overcome static friction. volatile int speedback = 0; // 136 (w 2 pretty full 9V batteries) is lowest speed that will overcome static friction. void get_char(volatile unsigned char *pins, unsigned char pin, char *rxbyte) { // // read character into rxbyte on pins pin // assumes line driver (inverts bits) // *rxbyte = 0; while (pin_test(*pins,pin)) // // wait for start bit // ; // // delay to middle of first data bit // half_bit_delay(); bit_delay(); // // unrolled loop to read data bits // if pin_test(*pins,pin) *rxbyte |= (1 << 0); else *rxbyte |= (0 << 0); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 1); else *rxbyte |= (0 << 1); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 2); else *rxbyte |= (0 << 2); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 3); else *rxbyte |= (0 << 3); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 4); else *rxbyte |= (0 << 4); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 5); else *rxbyte |= (0 << 5); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 6); else *rxbyte |= (0 << 6); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 7); else *rxbyte |= (0 << 7); // // wait for stop bit // bit_delay(); half_bit_delay(); } void get_char_quick(volatile unsigned char *pins, unsigned char pin, char *rxbyte) { // // read character into rxbyte on pins pin // assumes line driver (inverts bits) // *rxbyte = 0; /* int n = 1; */ /* int p = 0; */ /* while (n>0) { */ /* p = (!(pin_test(*pins,pin))); */ /* if (p) { */ /* n = 0;} */ /* n = n-1;} */ /* if (p) { */ // // wait for start bit // // // delay to middle of first data bit // half_bit_delay(); bit_delay(); // // unrolled loop to read data bits // if pin_test(*pins,pin) *rxbyte |= (1 << 0); else *rxbyte |= (0 << 0); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 1); else *rxbyte |= (0 << 1); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 2); else *rxbyte |= (0 << 2); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 3); else *rxbyte |= (0 << 3); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 4); else *rxbyte |= (0 << 4); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 5); else *rxbyte |= (0 << 5); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 6); else *rxbyte |= (0 << 6); bit_delay(); if pin_test(*pins,pin) *rxbyte |= (1 << 7); else *rxbyte |= (0 << 7); // // wait for stop bit // bit_delay(); half_bit_delay(); }//} void put_char(volatile unsigned char *port, unsigned char pin, char txchar) { // // send character in txchar on port pin // assumes line driver (inverts bits) // // start bit // clear(*port,pin); bit_delay(); // // unrolled loop to write data bits // if bit_test(txchar,0) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,1) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,2) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,3) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,4) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,5) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,6) set(*port,pin); else clear(*port,pin); bit_delay(); if bit_test(txchar,7) set(*port,pin); else clear(*port,pin); bit_delay(); // // stop bit // set(*port,pin); bit_delay(); } void put_string(volatile unsigned char *port, unsigned char pin, PGM_P str) { // // send character in txchar on port pin // assumes line driver (inverts bits) // static char chr; static int index; index = 0; do { chr = pgm_read_byte(&(str[index])); put_char(port, pin, chr); ++index; } while (chr != 0); } void delay_us(int n) { while(n--) { _delay_us(1); } } void delay_ms(int n) { while(n--) { _delay_ms(1); } } // This rotates the wheel either void rotate_wheel(int *to_move, int *to_not_move) { int n_tries = 10; int is_start_bit = 0; while (n_tries>0) { is_start_bit = (!(pin_test(serial_pins, serial_pin_in))); if (is_start_bit) { n_tries = 0;} n_tries = n_tries-1;} if (is_start_bit) { get_char_quick(&serial_pins, serial_pin_in, &chr); *to_move = (int)chr; *to_not_move = 0; } /* clear(bridge_port,IN2); */ /* clear(bridge_port, IN1); */ /* delay_ms(1000); */ } int main(void) { // // set clock divider to /1 // CLKPR = (1 << CLKPCE); CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0); // // initialize output pins // set(serial_port, serial_pin_out); input(serial_direction, serial_pin_out); // // initialize H-bridge pins // clear(bridge_port, IN1); output(bridge_direction, IN1); clear(bridge_port, IN2); output(bridge_direction, IN2); // // set up timer 1 // TCCR1A = (1 << COM1A1) | (0 << COM1A0); // clear OC1A on compare match TCCR1A |= (1 << COM1B1) | (0 << COM1B0); // clear OC1B on compare match TCCR1B = (0 << CS12) | (1 << CS11) | (0 << CS10) | (1 << WGM13); // prescaler /8, phase and frequency correct PWM, ICR1 TOP ICR1 = 255; // ~20 ms frequency // // set PWM pin to output // clear(PWM_port, PWM1); output(PWM_direction, PWM1); clear(PWM_port, PWM2); output(PWM_direction, PWM2); // // main loop // OCR1A = 0; while (1) { get_char(&serial_pins, serial_pin_in, &chr); if ((chr == 'p')) { // p for left, n for right /* get_char(&serial_pins, serial_pin_in, &chr); */ /* get_char(&serial_pins, serial_pin_in, &chr); */ get_char(&serial_pins, serial_pin_in, &chr); OCR1A = 1*(int)chr; OCR1B = 0; /* get_char(&serial_pins, serial_pin_in, &chr); */ /* OCR1B = 100*(int)chr; */ /* get_char(&serial_pins, serial_pin_in, &chr); */ /* get_char(&serial_pins, serial_pin_in, &chr); */ } if ((chr == 'o')) { // o for left, m for right get_char(&serial_pins, serial_pin_in, &chr); OCR1B = 1*(int)chr; OCR1A = 0; } } }