181 lines
3.8 KiB
C
181 lines
3.8 KiB
C
#include <stdlib.h>
|
|
#include <avr/io.h>
|
|
#include <avr/interrupt.h>
|
|
#include <avr/pgmspace.h>
|
|
#include <util/delay.h>
|
|
#include <string.h>
|
|
#include "utils.h"
|
|
#include "main.h"
|
|
#include "uart.h"
|
|
|
|
#define POWER_MIN 0
|
|
#define POWER_MAX 400
|
|
#define SERVO_STEPS 125
|
|
|
|
#define BUFSIZE 10
|
|
|
|
volatile uint16_t syscounter = 0;
|
|
volatile uint16_t power;
|
|
uint8_t data_count = 0;
|
|
char data_in[BUFSIZE];
|
|
|
|
|
|
void reset_input_buffer(void) {
|
|
data_count = 0;
|
|
memset(data_in, 0, BUFSIZE);
|
|
}
|
|
|
|
static void timer_init(void) {
|
|
// CTC Mode for Timer 1 (16Bit) with prescale of 64
|
|
TCCR1B |= _BV(WGM12) | _BV(CS11) | _BV(CS10);
|
|
OCR1A = 2250; // set Servo to max. position
|
|
TIMSK |= _BV(OCIE1A); // enable timer interrupt
|
|
TCCR1A |= _BV(COM1A0); // toggle OCR1A on overflow
|
|
|
|
// CTC Mode for Timer 0 (8Bit) with prescale of 1024
|
|
TCCR0B |= _BV(CS02) | _BV(CS00); // prescaler
|
|
TCCR0A |= _BV(WGM01); // CTC mode
|
|
TIMSK |= _BV(OCIE0A); // enable timer interrupt
|
|
|
|
OCR0A = 78; // gives us ~100ms interval
|
|
}
|
|
|
|
static void ports_init(void) {
|
|
DDRB |= _BV(PB3);
|
|
}
|
|
|
|
static void work_uart() {
|
|
uint16_t c = uart_getc();
|
|
|
|
if ( !(c & UART_NO_DATA) ) {
|
|
char cur = c & 0xff;
|
|
|
|
data_in[data_count] = cur;
|
|
//uart_print_uint8(cur);
|
|
|
|
data_count++;
|
|
if(data_count >= BUFSIZE) { // buffer overflow
|
|
reset_input_buffer();
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
for(uint8_t i=0;i<BUFSIZE;i++) {
|
|
uart_print_uint8(data_in[i]);
|
|
uart_putc('\r');
|
|
uart_putc('\n');
|
|
}
|
|
uart_puts_P(" -- \r\n");
|
|
#endif
|
|
|
|
if (cur == '\n' && data_count > 1) { // \n
|
|
|
|
power = atol(data_in);
|
|
if(power > POWER_MAX) power = POWER_MAX;
|
|
|
|
#ifdef DEBUG
|
|
uart_puts_P("power = ");
|
|
uart_print_uint16(power);
|
|
uart_puts_P("\r\n");
|
|
|
|
#endif
|
|
|
|
set_servo(power);
|
|
|
|
reset_input_buffer();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* \brief set the servo to a position calculated to given power
|
|
*
|
|
* \param display The power value from 0 to 400 (including bounds)
|
|
*/
|
|
void set_servo(uint16_t display) {
|
|
|
|
if( display > POWER_MAX ) display = POWER_MAX;
|
|
|
|
display = POWER_MAX-display; // invert the value / servo
|
|
|
|
display = display * 10; // *10 otherwise we need float
|
|
display = display / ((POWER_MAX * 10) / SERVO_STEPS);
|
|
display = display + SERVO_STEPS;
|
|
|
|
#ifdef DEBUG
|
|
uart_puts_P("display = ");
|
|
uart_print_uint16(display);
|
|
uart_puts_P("\r\n");
|
|
#endif
|
|
|
|
if( display < 125 ) display = 125; // just make sure, the timer
|
|
if( display > 250 ) display = 250; // is never out ouf 20ms grid
|
|
|
|
|
|
// check if timer is currently in the small pulse, then sleep here 2ms
|
|
// and do again
|
|
if(OCR1A < 2250) {
|
|
_delay_ms(2);
|
|
}
|
|
|
|
cli(); // read and write atomic
|
|
OCR1A = 2500-display;
|
|
sei();
|
|
}
|
|
|
|
|
|
/**
|
|
* \brief the method moves the servo one complete cycle
|
|
*/
|
|
static void demo_display(void) {
|
|
set_servo(0);
|
|
wait(100);
|
|
set_servo(400);
|
|
wait(100);
|
|
set_servo(0);
|
|
wait(100);
|
|
}
|
|
|
|
|
|
int main(void) {
|
|
|
|
sei();
|
|
ports_init();
|
|
timer_init();
|
|
uart_init(UART_BAUD_SELECT(38400,F_CPU));
|
|
reset_input_buffer();
|
|
demo_display();
|
|
|
|
|
|
while(1) {
|
|
work_uart();
|
|
|
|
if(syscounter >= 100) {
|
|
reset_input_buffer();
|
|
uart_putc('a'); // send a to receive values from master box
|
|
syscounter = 0;
|
|
|
|
#ifdef DEBUG
|
|
uart_puts_P("OCR1A = ");
|
|
uart_print_uint16(OCR1A);
|
|
uart_puts_P("\r\n");
|
|
#endif
|
|
}
|
|
}
|
|
|
|
return(0);
|
|
}
|
|
|
|
/**
|
|
* \brief this is our timer for PWM generation and system clock
|
|
* the system clock varies a bit, but this does not matter
|
|
*/
|
|
ISR(TIMER1_COMPA_vect) {
|
|
OCR1A = 2500-OCR1A; // Das Servosignal wird aus der Differenz von
|
|
// Periodenlänge (2500*0,008ms=20ms) und letztem
|
|
// Vergleichswert (OCR1A) gebildet
|
|
}
|
|
|
|
ISR(TIMER0_COMPA_vect) {
|
|
syscounter++;
|
|
}
|