4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2003, 2004, 2006 Develer S.r.l. (http://www.develer.com/)
30 * Copyright 2000 Bernardo Innocenti <bernie@codewiz.org>
34 * \brief ADC: Analogic to Digital Converter
39 * \author Andrea Grandi <andrea@develer.com>
42 #include "hw/hw_adc.h"
45 #include <cfg/macros.h>
47 #include <drv/timer.h>
51 /** Set the active AI channel */
52 void adc_set_active_ain(int ai)
54 /* If number of channels is <= 4 we use the first two MUX bits */
55 STATIC_ASSERT(ADC_CHANNEL_NUM <= 4);
63 /** Initialize the ADC */
66 /* Set analog IN as input */
67 DDRF &= ~(BV(PF0) | BV(PF1) | BV(PF2) | BV(PF3));
70 PORTF &= ~(BV(PF0) | BV(PF1) | BV(PF2) | BV(PF3));
76 /* Set the Division Factor to 128 */
77 ADCSRA |= (BV(ADPS0) | BV(ADPS1) | BV(ADPS2));
80 /** Set the initial reference */
81 void adc_set_vref_avcc(void)
87 /** Read the specified AI channel */
88 int adc_read_ai_channel(int channel)
90 adc_set_active_ain(channel);
91 timer_udelay(STABILIZING_AI_CHANNEL_TIME);
94 while(ADCSRA & BV(ADSC))
97 * Intentionally empty loop.
98 * It waits the convertion to be completed by ADC
106 val |= (uint16_t)ADCH << 8;