MHVLib
20111011
An efficiency oriented runtime library for AVR microcontrollers
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00001 /* Copyright (c) 2011, Make, Hack, Void Inc 00002 * All rights reserved. 00003 * 00004 * Redistribution and use in source and binary forms, with or without 00005 * modification, are permitted provided that the following conditions are met: 00006 * * Redistributions of source code must retain the above copyright 00007 * notice, this list of conditions and the following disclaimer. 00008 * * Redistributions in binary form must reproduce the above copyright 00009 * notice, this list of conditions and the following disclaimer in the 00010 * documentation and/or other materials provided with the distribution. 00011 * * Neither the name of the Make, Hack, Void nor the 00012 * names of its contributors may be used to endorse or promote products 00013 * derived from this software without specific prior written permission. 00014 * 00015 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 00016 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 00017 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 00018 * DISCLAIMED. IN NO EVENT SHALL MAKE, HACK, VOID BE LIABLE FOR ANY 00019 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 00020 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00021 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 00022 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00023 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00024 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00025 */ 00026 00027 #include "MHV_AD.h" 00028 00029 uint16_t mhv_ad_busyRead(uint8_t channel, uint8_t reference) { 00030 ADMUX = reference | (channel & 0x0F); 00031 00032 #ifdef MUX5 00033 ADCSRB = (ADCSRB & ~_BV(MUX5)) | ((channel & _BV(5) >> (5-MUX5))); 00034 #endif 00035 00036 // Start the conversion 00037 ADCSRA |= _BV(ADSC); 00038 00039 while (ADCSRA & _BV(ADSC)) {}; 00040 00041 return ADC; 00042 } 00043 00044 void mhv_ad_asyncRead(uint8_t channel, uint8_t reference) { 00045 ADMUX = reference | (channel & 0x0F); 00046 00047 #ifdef MUX5 00048 ADCSRB = (ADCSRB & ~_BV(MUX5)) | ((channel & _BV(5) >> (5-MUX5))); 00049 #endif 00050 00051 // Start the conversion 00052 ADCSRA |= _BV(ADSC); 00053 } 00054 00055 void mhv_ad_setPrescaler(MHV_AD_PRESCALER prescaler) { 00056 ADCSRA = (ADCSRA & 0xf8) | (prescaler & 0x7); 00057 }