1wire-tester/main.c

#include <avr/io.h>          // register definitions
#include <avr/pgmspace.h>    // storing data in program memory
#include <avr/interrupt.h>   // interrupt vectors
#include <util/delay.h>      // delay functions

#include <stdint.h>          // C header for int types like uint8_t
#include <stdbool.h>         // C header for the bool type
#include <stdlib.h>
#include <stdio.h>

// Include stuff from the library
#include "lib/iopins.h"
#include "lib/usart.h"
#include "lcd.h"
#include "onewire.h"


// Pins
#define LED 13

#define OW_PIN D9

void _lcd_wait_bf();
void _lcd_write_byte(uint8_t bb);

#if 0
// UART receive handler
ISR(USART_RX_vect)
{
	// "ECHO" function:
	uint8_t b = usart_rx();
	usart_tx(b); // send back
}
#endif

void main()
{
#if 0
	usart_init(BAUD_115200);
	usart_isr_rx_enable(true); // enable RX interrupt handler
#endif

	// configure pins
	as_output(LED);

	lcd_init();

    lcd_clear();
    lcd_puts("");

	// globally enable interrupts (for the USART_RX handler)
	sei();

	uint8_t addr[8];
	char charbuf[21];

	int dots = 0;
	bool signal = false, last_signal;
	while (1) {
        last_signal = signal;
        signal = ow_reset(OW_PIN);
        if (!signal) {
            if (last_signal) {
                lcd_clear();
            }
            lcd_puts_xy(0,0,"No 1-Wire detected..");
            dots = 0;
        } else {
            if (!last_signal) {
                lcd_clear();
            }

            ow_write(OW_PIN, 0x33);
            ow_read_arr(OW_PIN, addr, 8);

            // Show chip type
            switch (addr[0]) {
                case 0x10:
                    sprintf(charbuf, "18S20  ");
                    break;

                case 0x28:
                    sprintf(charbuf, "18B20  ");
                    break;

                case 0x01:
                    sprintf(charbuf, "iButton");
                    break;

                default:
                    sprintf(charbuf, "UNKNOWN");
                    break;
            }
            lcd_puts_xy(12, 0, charbuf);

            // Show address
            char *p = charbuf;
            for(uint8_t i = 0; i < 4; i++) {
                p += sprintf(p, "%02X", addr[i]);
                if (i < 3) *p++ = ':';
            }
            lcd_puts_xy(0, 0, charbuf);


            p = charbuf;
            for(uint8_t i = 0; i < 4; i++) {
                p += sprintf(p, "%02X", addr[4+i]);
                if (i < 3) *p++ = ':';
            }
            lcd_puts_xy(0, 1, charbuf);

            // Measure temperature
            int16_t cels;
            if (addr[0] == 0x10 || addr[0] == 0x28) {
                ds18x20_single_measure(OW_PIN);
                if (addr[0] == 0x10) {
                    // 18S20
                    cels = ds18s20_read_temp_c(OW_PIN);
                } else {
                    // 18B20
                    cels = ds18b20_read_temp_c(OW_PIN);
                }

                if (cels == TEMP_ERROR || cels == 850) {
                    lcd_xy(12, 1);
                    for (uint8_t i = 0; i <= dots; i++) {
                        lcd_putc('.');
                    }
                    dots = (dots + 1) % 3;
                }
                else {
                    p = charbuf;

                    if (cels < 0) {
                        *p++ = '-';
                        cels = -cels;
                    }

                    p += sprintf(p, "%d", cels / 10);
                    *p++ = '.';
                    p += sprintf(p, "%d", cels % 10);
                    *p++ = 0xDF; // ring symbol
                    *p++ = 'C';
                    *p++ = ' '; // padding to prevent artifacts if the number shrinks (we're not clearing screen when 1w is connected)
                    *p++ = ' ';
                    *p++ = ' ';
                    *p = 0;

                    lcd_puts_xy(12, 1, charbuf);
                }
            }
        }

		pin_toggle(13); // blink the LED
        _delay_ms(100);
	}
}