Contiki 2.6

sky-sensors.c

00001 /*
00002  * Copyright (c) 2010, Swedish Institute of Computer Science.
00003  * All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the Institute nor the names of its contributors
00014  *    may be used to endorse or promote products derived from this software
00015  *    without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00027  * SUCH DAMAGE.
00028  *
00029  * This file is part of the Contiki operating system.
00030  *
00031  * $Id: sky-sensors.c,v 1.3 2010/08/25 19:30:53 nifi Exp $
00032  *
00033  * -----------------------------------------------------------------
00034  *
00035  * Author  : Joakim Eriksson
00036  * Created : 2010-02-02
00037  * Updated : $Date: 2010/08/25 19:30:53 $
00038  *           $Revision: 1.3 $
00039  */
00040 #include "contiki.h"
00041 #include "lib/sensors.h"
00042 
00043 #define ADC12MCTL_NO(adcno) ((unsigned char *) ADC12MCTL0_)[adcno]
00044 
00045 static uint16_t adc_on;
00046 static uint16_t ready;
00047 /*---------------------------------------------------------------------------*/
00048 static CC_INLINE void
00049 start(void)
00050 {
00051   uint16_t c, last;
00052 
00053   /* Set up the ADC. */
00054   P6DIR = 0xff;
00055   P6OUT = 0x00;
00056 
00057   /* Setup ADC12, ref., sampling time */
00058   /* XXX Note according to the specification a minimum of 17 ms should
00059      be allowed after turn on of the internal reference generator. */
00060   ADC12CTL0 = REF2_5V + SHT0_6 + SHT1_6 + MSC + REFON;
00061   /* Use sampling timer, repeat-sequence-of-channels */
00062   ADC12CTL1 = SHP + CONSEQ_3;
00063 
00064   last = 15;
00065   for(c = 0; c < 16; c++) {
00066     /* Clear all end-of-sequences */
00067     ADC12MCTL_NO(c) &= ~EOS;
00068     if(adc_on & (1 << c)) {
00069       if(last == 15) {
00070         /* Set new start of sequence to lowest active memory holder */
00071         ADC12CTL1 |= (c * CSTARTADD_1);
00072       }
00073       last = c;
00074     }
00075   }
00076 
00077   /* Set highest end-of-sequence. */
00078   ADC12MCTL_NO(last) |= EOS;
00079 
00080   ADC12CTL0 |= ADC12ON;
00081   ADC12CTL0 |= ENC;                   /* enable conversion */
00082   ADC12CTL0 |= ADC12SC;               /* sample & convert */
00083 }
00084 /*---------------------------------------------------------------------------*/
00085 static CC_INLINE void
00086 stop(void)
00087 {
00088   /* stop converting immediately, turn off reference voltage, etc. */
00089 
00090   ADC12CTL0 &= ~ENC;
00091   /* need to remove CONSEQ_3 if not EOS is configured */
00092   ADC12CTL1 &= ~CONSEQ_3;
00093 
00094   /* wait for conversion to stop */
00095   while(ADC12CTL1 & ADC12BUSY);
00096 
00097   /* clear any pending interrupts */
00098   ADC12IFG = 0;
00099 }
00100 /*---------------------------------------------------------------------------*/
00101 int
00102 sky_sensors_status(uint16_t input, int type)
00103 {
00104   if(type == SENSORS_ACTIVE) {
00105     return (adc_on & input) == input;
00106   }
00107   if(type == SENSORS_READY) {
00108     ready |= ADC12IFG & adc_on & input;
00109     return (ready & adc_on & input) == input;
00110   }
00111   return 0;
00112 }
00113 /*---------------------------------------------------------------------------*/
00114 int
00115 sky_sensors_configure(uint16_t input, uint8_t ref, int type, int value)
00116 {
00117   uint16_t c;
00118 
00119   if(type == SENSORS_ACTIVE) {
00120     stop();
00121 
00122     if(value) {
00123       adc_on |= input;
00124       P6SEL |= input & 0xff;
00125 
00126       /* Set ADC config */
00127       for(c = 0; c < 16; c++) {
00128         if(input & (1 << c)) {
00129           ADC12MCTL_NO(c) = (c * INCH_1) | ref;
00130         }
00131       }
00132 
00133     } else {
00134       adc_on &= ~input;
00135       ready &= ~input;
00136       P6SEL &= ~(input & 0xff);
00137     }
00138 
00139     if(adc_on == 0) {
00140       P6DIR = 0x00;
00141       P6SEL = 0x00;
00142 
00143       /* Turn off ADC and internal reference generator */
00144       ADC12CTL0 = 0;
00145       ADC12CTL1 = 0;
00146     } else {
00147       start();
00148     }
00149     return 1;
00150   }
00151   return 0;
00152 }
00153 /*---------------------------------------------------------------------------*/