/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id: adc.c,v 1.2 2002/07/01 10:55:47 linusnielsen Exp $ * * Copyright (C) 2002 by Linus Nielsen Feltzing * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include "config.h" #include "sh7034.h" #include "kernel.h" #include "thread.h" #include "adc.h" #ifdef ARCHOS_FMRECORDER #define BATTERY_LEVEL_FULL_SCALE 619 #define BATTERY_LEVEL_BOGUS 77 short last_good_battery_level = BATTERY_LEVEL_FULL_SCALE; #endif static int current_channel; static unsigned short adcdata[NUM_ADC_CHANNELS]; static unsigned int adcreg[NUM_ADC_CHANNELS] = { ADDRAH_ADDR, ADDRBH_ADDR, ADDRCH_ADDR, ADDRDH_ADDR, ADDRAH_ADDR, ADDRBH_ADDR, ADDRCH_ADDR, ADDRDH_ADDR }; static void adc_tick(void) { /* Read the data that has bee converted since the last tick */ adcdata[current_channel] = *(unsigned short *)adcreg[current_channel] >> 6; /* Start a conversion on the next channel */ current_channel++; if(current_channel == NUM_ADC_CHANNELS) current_channel = 0; ADCSR = ADCSR_ADST | current_channel; } unsigned short adc_read(int channel) { #ifdef ARCHOS_FMRECORDER short value = adcdata[channel]; if (channel == ADC_UNREG_POWER) { if (value < BATTERY_LEVEL_BOGUS) { value = last_good_battery_level; } else { last_good_battery_level = value; } } return value; #else return adcdata[channel]; #endif } void adc_init(void) { ADCR = 0; /* No external trigger */ current_channel = 0; tick_add_task(adc_tick); }