osd-contiki/examples/sensinode/sensors/sensors-example.c
2012-03-23 14:41:07 +00:00

373 lines
13 KiB
C

/*
* 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
* Example to demonstrate-test the sensors functionality on
* sensinode/cc2430 devices.
*
* B1 turns L2 on and off.
* B2 reboots the node via the watchdog.
*
* The node takes readings from the various sensors every x seconds and
* prints out the results.
*
* We use floats here to translate the AD conversion results to
* meaningful values. However, our printf does not have %f support so
* we use an ugly hack to print out the value by extracting the integral
* part and then the fractional part. Don't try this at home.
*
* Temperature:
* Math is correct, the sensor needs calibration per device.
* I currently use default values for the math which may result in
* very incorrect values in degrees C.
* See TI Design Note DN102 about the offset calibration.
*
* Supply Voltage (VDD) and Battery Sensor:
* For VDD, math is correct, conversion is correct. See DN101 for details if
* interested.
* Battery reports different values when we run it many times
* in succession. The cause is unknown.
* I am fairly confident that I have captured the connections on the
* device correctly. I am however accepting input/feedback
*
* Light Sensor (Vishay Semiconductors TEPT4400):
* I am uncertain about the math. This needs testing. All I know is
* that 600lux = 0.9V and that the relation is linear. See inline for
* more details
*
* Accelerometer (Freescale Semiconductor MMA7340L):
* Math is correct but the sensor needs calibration. I've not
* attempted one cause the reported values differ per device.
* Place the N740 with the logo facing down to get 1g on the Z axis.
* Place the antenna side facing down to get 1g on the Y axis
* Place the N740 on its longer side while looking at the antenna and
* the D connector. Antenna on the bottom, D connector on the top.
* This should give you 1g on the X axis.
*
* Make sure you enable/disable things in contiki-conf.h
*
* \author
* George Oikonomou - <oikonomou@users.sourceforge.net>
*/
#include "contiki.h"
#include "contiki-conf.h"
#include "net/rime.h"
#include "dev/leds.h"
#include "dev/watchdog.h"
#include "lib/random.h"
#if CONTIKI_TARGET_SENSINODE
#include "dev/sensinode-sensors.h"
#else
#include "lib/sensors.h"
#endif
#define DEBUG 1
#if DEBUG
#include <stdio.h>
#if CONTIKI_TARGET_SENSINODE
#include "sensinode-debug.h"
#endif /* CONTIKI_TARGET_SENSINODE */
#define PRINTF(...) printf(__VA_ARGS__)
#else /* DEBUG */
/* We overwrite (read as annihilate) all output functions here */
#define PRINTF(...)
#define putstring(...)
#define putchar(...)
#endif /* DEBUG */
#define SEND_BATTERY_INFO 0
#if SEND_BATTERY_INFO
#include "sensors-example.h"
static void bc_rx(struct broadcast_conn *c, const rimeaddr_t *from) {
return;
}
static const struct broadcast_callbacks bc_cb = { bc_rx };
static struct broadcast_conn bc_con;
#endif
#if BUTTON_SENSOR_ON
extern const struct sensors_sensor button_1_sensor, button_2_sensor;
#endif
/*---------------------------------------------------------------------------*/
PROCESS(sensors_test_process, "Sensor Test Process");
#if (CONTIKI_TARGET_SENSINODE && BUTTON_SENSOR_ON)
PROCESS(buttons_test_process, "Button Test Process");
AUTOSTART_PROCESSES(&sensors_test_process, &buttons_test_process);
#else
AUTOSTART_PROCESSES(&sensors_test_process);
#endif
/*---------------------------------------------------------------------------*/
#if BUTTON_SENSOR_ON
PROCESS_THREAD(buttons_test_process, ev, data)
{
struct sensors_sensor *sensor;
PROCESS_BEGIN();
while (1) {
PROCESS_WAIT_EVENT_UNTIL(ev == sensors_event);
/* If we woke up after a sensor event, inform what happened */
sensor = (struct sensors_sensor *)data;
if(sensor == &button_1_sensor) {
leds_toggle(LEDS_GREEN);
} else if(sensor == &button_2_sensor) {
watchdog_reboot();
}
}
PROCESS_END();
}
#endif
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(sensors_test_process, ev, data)
{
static struct etimer et;
#if SEND_BATTERY_INFO
/* Node Time */
static struct sensor_data sd;
#endif
/* Sensor Values */
static int rv;
static struct sensors_sensor * sensor;
static float sane = 0;
static int dec;
static float frac;
#if SEND_BATTERY_INFO
PROCESS_EXITHANDLER(broadcast_close(&bc_con);)
#endif
PROCESS_BEGIN();
putstring("========================\n");
putstring("Starting Sensor Example.\n");
putstring("========================\n");
#if SEND_BATTERY_INFO
broadcast_open(&bc_con, BATTERY_RIME_CHANNEL, &bc_cb);
#endif
/* Set an etimer. We take sensor readings when it expires and reset it. */
etimer_set(&et, CLOCK_SECOND * 2);
while (1) {
PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));
/*
* Request some ADC conversions
* Return value -1 means sensor not available or turned off in conf
*/
sensor = sensors_find(ADC_SENSOR);
if (sensor) {
putstring("------------------\n");
leds_on(LEDS_RED);
/*
* Temperature:
* Using 1.25V ref. voltage (1250mV).
* Typical Voltage at 0°C : 743 mV
* Typical Co-efficient : 2.45 mV/°C
* Offset at 25°C : 30 (this varies and needs calibration)
*
* Thus, at 12bit resolution:
*
* ADC x 1250 / 2047 - (743 + 30) 0.61065 x ADC - 773
* T = ------------------------------ ~= ------------------- °C
* 2.45 2.45
*/
rv = sensor->value(ADC_SENSOR_TYPE_TEMP);
if(rv != -1) {
sane = ((rv * 0.61065 - 773) / 2.45);
dec = sane;
frac = sane - dec;
PRINTF(" Temp=%d.%02u C (%d)\n", dec, (unsigned int)(frac*100), rv);
}
/*
* Accelerometer: Freescale Semiconductor MMA7340L
* Using 1.25V ref. voltage.
* Sensitivity: 0.44 mV/g in ±3g mode.
* 0.1175 mV/g in ±11g mode.
* Typical 0g Vout = 1.65V (both modes, Vdd=3.3V, T=25°C)
* ADC Input Voltage is 1/3 Accelerometer Output Voltage
*
* +3g -> 2.97V Acc Out -> 0.9900V ADC Input -> 1621
* +1g -> 2.09V Acc Out -> 0.6967V ADC Input -> 1141
* 0g -> 1.65V Acc Out -> 0.5500V ADC Input -> 901
* -1g -> 1.21V Acc Out -> 0.4033V ADC Input -> 660
* -3g -> 0.33V Acc Out -> 0.1100V ADC Input -> 180
*
* Thus, at 12bit resolution, ±3g mode:
* ADC x 1.25 x 3
* Vout = -------------- V
* 2047
*
* Vout - 0g Vout - 1.65
* Acc = ----------- = ----------- g
* Sensitivity 0.44
*
* Similar calc. for ±11g with 0.1175V increments
*
* This is only valid if you set ACC_SENSOR_CONF_GSEL 0 in contiki-conf.h
*/
rv = sensor->value(ADC_SENSOR_TYPE_ACC_X);
if(rv != -1) {
sane = ((rv * 3.75 / 2047) - 1.65) / 0.44;
dec = sane;
frac = sane - dec;
frac = (frac < 0) ? -frac : frac;
/*
* This will fail for numbers like -0.xyz (since there is no such thing
* as -0. We manually add a minus sign in the printout if sane is neg
* and dec is 0.
* This is the wrong way to do it...
*/
putstring(" AccX=");
if(sane < 0 && dec == 0) {
putchar('-');
}
PRINTF("%d.%02ug (%d)\n", dec, (unsigned int)(frac*100), rv);
}
rv = sensor->value(ADC_SENSOR_TYPE_ACC_Y);
if(rv != -1) {
sane = ((rv * 3.75 / 2047) - 1.65) / 0.44;
dec = sane;
frac = sane - dec;
frac = (frac < 0) ? -frac : frac;
putstring(" AccY=");
if(sane < 0 && dec == 0) {
putchar('-');
}
PRINTF("%d.%02ug (%d)\n", dec, (unsigned int)(frac*100), rv);
}
rv = sensor->value(ADC_SENSOR_TYPE_ACC_Z);
if(rv != -1) {
sane = ((rv * 3.75 / 2047) - 1.65) / 0.44;
dec = sane;
frac = sane - dec;
frac = (frac < 0) ? -frac : frac;
putstring(" AccZ=");
if(sane < 0 && dec == 0) {
putchar('-');
}
PRINTF("%d.%02ug (%d)\n", dec, (unsigned int)(frac*100), rv);
}
/*
* Light: Vishay Semiconductors TEPT4400
* Using 1.25V ref. voltage.
* For 600 Lux illuminance, the sensor outputs 1mA current (0.9V ADC In)
* 600 lux = 1mA output => 1473 ADC value at 12 bit resolution)
*
* Thus, at 12bit resolution:
* 600 x 1.25 x ADC
* Lux = ---------------- ~= ADC * 0.4071
* 2047 x 0.9
*/
rv = sensor->value(ADC_SENSOR_TYPE_LIGHT);
if(rv != -1) {
sane = (float)(rv * 0.4071);
dec = sane;
frac = sane - dec;
PRINTF(" Light=%d.%02ulux (%d)\n", dec, (unsigned int)(frac*100), rv);
}
/*
* Power Supply Voltage.
* Using 1.25V ref. voltage.
* AD Conversion on VDD/3
*
* Thus, at 12bit resolution:
*
* ADC x 1.25 x 3
* Supply = -------------- V
* 2047
*/
rv = sensor->value(ADC_SENSOR_TYPE_VDD);
#if SEND_BATTERY_INFO
sd.vdd = rv;
#endif
if(rv != -1) {
sane = rv * 3.75 / 2047;
dec = sane;
frac = sane - dec;
PRINTF("Supply=%d.%02uV (%d)\n", dec, (unsigned int)(frac*100), rv);
/* Store rv temporarily in dec so we can use it for the battery */
dec = rv;
}
/*
* Battery Voltage - Only 2/3 of the actual voltage reach the ADC input
* Using 1.25V ref. voltage would result in 2047 AD conversions all the
* time since ADC-in would be gt 1.25. We thus use AVDD_SOC as ref.
*
* Thus, at 12bit resolution (assuming VDD is 3.3V):
*
* ADC x 3.3 x 3 ADC x 4.95
* Battery = ------------- = ---------- V
* 2047 x 2 2047
*
* Replacing the 3.3V with an ADC reading of the actual VDD would yield
* better accuracy. See monitor-node.c for an example.
*
* 3 x ADC x VDD x 3.75 ADC x VDD x 11.25
* Battery = -------------------- = ----------------- V
* 2 x 2047 x 2047 0x7FE002
*
*/
rv = sensor->value(ADC_SENSOR_TYPE_BATTERY);
if(rv != -1) {
/* Instead of hard-coding 3.3 here, use the latest VDD (stored in dec)
* (slightly inaccurate still, but better than crude 3.3) */
sane = (11.25 * rv * dec) / (0x7FE002);
dec = sane;
frac = sane - dec;
PRINTF(" Batt.=%d.%02uV (%d)\n", dec, (unsigned int)(frac*100), rv);
#if SEND_BATTERY_INFO
sd.bat = rv;
packetbuf_copyfrom(&sd, sizeof(sd));
broadcast_send(&bc_con);
#endif
}
leds_off(LEDS_RED);
}
etimer_reset(&et);
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/