contiki/platform/sensinode/dev/adc-sensor.c

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2012-03-05 16:28:06 +00:00
/*
* Copyright (c) 2010, Loughborough University - Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*/
/**
* \file
* ADC sensor module for sensinode devices.
*
* This file respects configuration in contiki-conf.h. It also turns
* off features which are not present in the model that we are
* building for.
*
* \author
* George Oikonomou - <oikonomou@users.sourceforge.net>
*/
#include "dev/sensinode-sensors.h"
#if ADC_SENSOR_ON
SENSORS_SENSOR(adc_sensor, ADC_SENSOR, value, configure, status);
static uint8_t ready;
/*---------------------------------------------------------------------------*/
static int
value(int type)
{
uint16_t reading;
/*
* For single-shot AD conversions, we may only write to ADCCON3[3:0] once
* (This write triggers the conversion). We thus use the variable 'command'
* to store intermediate steps (reference, decimation rate, input channel)
*/
uint8_t command;
ADCCFG = 0; /* Enables/Disables Input Channel */
/* 1.25V ref, max decimation rate */
command = ADEDIV1 | ADEDIV0;
/* Clear the Interrupt Flag */
TCON_ADCIF = 0;
/* Depending on the desired reading, append the input bits to 'command' and
* enable the corresponding input channel in ADCCFG if necessary */
switch(type) {
#if TEMP_SENSOR_ON
case ADC_SENSOR_TYPE_TEMP:
command |= ADECH3 | ADECH2 | ADECH1;
break;
#endif
#if ACC_SENSOR_ON
case ADC_SENSOR_TYPE_ACC_X:
ADCCFG = ADC5EN;
command |= ADECH2 | ADECH0;
break;
case ADC_SENSOR_TYPE_ACC_Y:
ADCCFG = ADC6EN;
command |= ADECH2 | ADECH1;
break;
case ADC_SENSOR_TYPE_ACC_Z:
ADCCFG = ADC7EN;
command |= ADECH2 | ADECH1 | ADECH0;
break;
#endif
#if VDD_SENSOR_ON
case ADC_SENSOR_TYPE_VDD:
command |= ADECH3 | ADECH2 | ADECH1 | ADECH0;
break;
#endif
#if LIGHT_SENSOR_ON
case ADC_SENSOR_TYPE_LIGHT:
ADCCFG = ADC0EN;
break;
#endif
#if BATTERY_SENSOR_ON
case ADC_SENSOR_TYPE_BATTERY:
ADCCFG = ADC1EN;
command |= ADECH0 | ADEREF1; /* AVDD_SOC reference */
break;
#endif
default:
/* If the sensor is not present or disabled in conf, return -1 */
return -1;
}
/* Writing in bits 3:0 of ADCCON3 will trigger a single conversion */
ADCCON3 = command;
/*
* When the conversion is complete, the ADC interrupt flag is set. We don't
* use an ISR here, we just wait on the flag and clear it afterwards.
*/
while(!TCON_ADCIF);
/* Clear the Interrupt Flag */
TCON_ADCIF = 0;
reading = 0;
reading = ADCL;
reading |= (((uint8_t) ADCH) << 8);
/* 12-bit decimation rate: 4 LS bits are noise */
reading >>= 4;
return reading;
}
/*---------------------------------------------------------------------------*/
static int
status(int type)
{
return ready;
}
/*---------------------------------------------------------------------------*/
/*
* On N740 we can control Ill and Acc individually:
* ADC_VAL_OTHERS 0x01
* ADC_VAL_LIGHT_ON 0x04
* ADC_VAL_ACC_ON 0x08
* ADC_VAL_ACC_GSEL 0x10
*
* Return Value is always light | acc | acc_gsel
*
* SENSORS_ACTIVE:
* - 1: Activate everything, use default setting for ACC G-select
* - 0: Turn everything off
* - xyz: Mask with the defines above and act accordingly.
*
* SENSORS_READY:
* - Return Status (0: all off or a value based on the defines above)
*/
static int
configure(int type, int value)
{
#ifdef MODEL_N740
/*
* Read current state of the ser-par, ignoring current sensor settings
* Those will be set all over depending on VALUE
*/
uint8_t ser_par_val = n740_ser_par_get() & 0xF2;
#endif /* MODEL_N740 */
/* 'Others' are either compiled in or not. Can't be turned on/off */
ready = ADC_VAL_ALL;
switch(type) {
case SENSORS_HW_INIT:
case SENSORS_ACTIVE:
#ifdef MODEL_N740
if(value == ADC_VAL_ALL) {
value = ADC_VAL_ACC_ON | ADC_VAL_LIGHT_ON;
#if ACC_SENSOR_GSEL
value |= ADC_VAL_ACC_GSEL;
#endif /* ACC_SENSOR_GSEL */
}
#endif /* MODEL_N740 */
/* OK, Now value definitely specifies our bits, start masking
* We will refuse to turn things on if they are specified OFF in conf. */
#ifdef MODEL_N740
#if ACC_SENSOR_ON
if(value & ADC_VAL_ACC_ON) {
P0SEL |= 0x80 | 0x40 | 0x20;
ser_par_val |= N740_SER_PAR_ACC;
ready |= ADC_VAL_ACC_ON;
#if ACC_SENSOR_GSEL
if(value & ADC_VAL_ACC_GSEL) {
ser_par_val |= N740_SER_PAR_ACC_GSEL;
ready |= ADC_VAL_ACC_GSEL;
}
#endif /*ACC_SENSOR_GSEL */
}
#endif /* ACC_SENSOR_ON */
#if LIGHT_SENSOR_ON
if(value & ADC_VAL_LIGHT_ON) {
ser_par_val |= N740_SER_PAR_LIGHT;
ready |= ADC_VAL_LIGHT_ON;
}
#endif /* LIGHT_SENSOR_ON */
n740_ser_par_set(ser_par_val);
#endif /* MODEL_N740 */
}
return ready;
}
#endif /* ADC_SENSOR_ON */