4 Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
6 This file is part of simavr.
8 simavr is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 simavr is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with simavr. If not, see <http://www.gnu.org/licenses/>.
24 #include <avr/interrupt.h>
25 #include <util/delay.h>
26 #include <avr/sleep.h>
29 * This demonstrate how to use the avr_mcu_section.h file
30 * The macro adds a section to the ELF file with useful
31 * information for the simulator
33 #include "avr_mcu_section.h"
34 AVR_MCU(F_CPU, "atmega644");
35 AVR_MCU_VOLTAGES(3300, 3300, 3300); // 3.3V VCC, AVCC, VREF
37 static int uart_putchar(char c, FILE *stream) {
39 uart_putchar('\r', stream);
40 loop_until_bit_is_set(UCSR0A, UDRE0);
45 static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,
48 volatile uint16_t adc_val[8];
52 uint8_t mux = ADMUX, l = ADCL, h = ADCH;
54 adc_val[i] = l | (h << 8);
56 ADMUX = (mux & 0xF0) | i;
58 ADCSRA |= (1 << ADSC); // restart one now on the new channel
64 ADMUX = (1 << REFS0); // use internal AVCC (3.3)
65 // enable ADC, start a conversion, with the interrupt
66 // and with a /128 integration clock
67 ADCSRA = (1 << ADEN) | (1 << ADSC) | (1 << ADIE) | 0x5;
68 // doesn't do anything in simavr for now
69 DIDR0 = 3; // disable digital on these 2 pins ADC0 and ADC1
77 printf("Read 8 ADC channels to test interrupts\n");
82 * The interupt reads all 8 ADCs then stop...
83 * so this loop will eventually exits
85 while (ADCSRA & (1 << ADSC))
88 printf("All done. Now reading the 1.1V value in pooling mode\n");
89 ADCSRA &= ~(1 << ADIE); // remove interrupt
91 // 1.1 reference voltage, left aligned
92 ADMUX = (ADMUX & ~0x1f)| (0 << ADLAR) | 0x1e;
93 ADCSRA |= (1 << ADSC) ; // start conversion
94 while (ADCSRA & (1 << ADSC))
96 uint16_t v = ADCL | (ADCH << 8);
97 uint16_t volts = (v * 3300L) >> 10; // div 1024
98 printf("Read ADC value %04x = %d mvolts -- ought to be 1098\n", v, volts);
100 ADCSRA &= ~(1 << ADEN); // disable ADC...