// // // 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 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 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 volatile int temp = 0; volatile char chr = '0'; 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 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); } } /* ISR(PCINT0_vect) { */ /* // */ /* // pin change interrupt handler */ /* // */ /* get_char(&serial_pins, serial_pin_in, &chr); */ /* temp = chr - '0'; */ /* output(serial_direction, serial_pin_out); */ /* put_char(&serial_port, serial_pin_out, chr); */ /* input(serial_direction, serial_pin_out); */ /* /\* static char message[] PROGMEM = "hello.ftdi.44.echo.interrupt.c: you typed "; *\/ */ /* /\* put_string(&serial_port, serial_pin_out, (PGM_P) message); *\/ */ /* /\* put_char(&serial_port, serial_pin_out, chr); *\/ */ /* /\* put_char(&serial_port, serial_pin_out, '!'); *\/ */ /* /\* put_char(&serial_port, serial_pin_out, 10); // new line *\/ */ /* } */ 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); // // set up pin change interrupt on input pin // /* set(GIMSK, serial_interrupt); */ /* set(PCMSK0, serial_interrupt_pin); */ /* sei(); */ // // initialize H-bridge pins // clear(bridge_port, IN1); output(bridge_direction, IN1); clear(bridge_port, IN2); output(bridge_direction, IN2); // // main loop // while (1) { get_char(&serial_pins, serial_pin_in, &chr); temp = chr - '0'; //put_char(&serial_port, serial_pin_out, chr); //_delay_ms(100); if (chr == 'm') { clear(bridge_port, IN1); set(bridge_port, IN2); get_char(&serial_pins, serial_pin_in, &chr); temp = chr - '0'; //stop motor 1 delay_ms(1000); clear(bridge_port, IN2); clear(bridge_port,IN1);} if (chr == '0') { clear(bridge_port, IN2); clear(bridge_port,IN1);} if (temp == 1) { //motor 1 forward clear(bridge_port, IN2); set(bridge_port, IN1);} if (temp == 2) { //motor 1 backwards clear(bridge_port, IN1); set(bridge_port, IN2);} // Switch to the following for the other motor: /* if (temp == 3) { */ /* //stop motor 2 */ /* clear(bridge_port, IN1); */ /* clear(bridge_port, IN2);} */ /* if (temp == 4) { */ /* //motor 2 forward */ /* clear(bridge_port, IN2); */ /* set(bridge_port, IN1);} */ /* if (temp == 5) { */ /* //motor 2 backwards */ /* clear(bridge_port, IN1); */ /* set(bridge_port, IN2);} */ // wait for interupt ; } }