79 lines
1.8 KiB
C
79 lines
1.8 KiB
C
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/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2006 by Wade Brown
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*
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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "cpu.h"
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#include "adc-target.h"
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void adc_init(void) {
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/* Turn on the ADC PCLK */
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CLKCON |= (1<<15);
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/* Set channel 0, normal mode, disable "start by read" */
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ADCCON &= ~(0x3F);
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/* No start delay. Use nromal conversion mode. */
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ADCDLY |= 0x1;
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/* Set and enable the prescaler */
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ADCCON = (ADCCON & ~(0xff<<6)) | (0x19<<6);
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ADCCON |= (1<<14);
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}
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unsigned short adc_read(int channel) {
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int i;
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/* Set the channel */
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ADCCON = (ADCCON & ~(0x7<<3)) | (channel<<3);
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/* Start the conversion process */
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ADCCON |= 0x1;
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/* Wait for a low Enable_start */
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i = 20000;
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while(i > 0) {
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if(ADCCON & 0x1) {
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i--;
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}
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else {
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break;
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}
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}
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if(i == 0) {
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/* Ran out of time */
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return(0);
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}
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/* Wait for high End_of_Conversion */
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i = 20000;
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while(i > 0) {
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if(ADCCON & (1<<15)) {
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break;
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}
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else {
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i--;
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}
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}
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if(i == 0) {
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/* Ran out of time */
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return(0);
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}
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return(ADCDAT0 & 0x3ff);
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}
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