tmp-007-sensor.c

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/*
 * Copyright (c) 2014, Texas Instruments Incorporated - http://www.ti.com/
 * 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 copyright holder 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDER 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.
 */
/*---------------------------------------------------------------------------*/
/**
 * \addtogroup sensortag-cc26xx-tmp-sensor
 * @{
 *
 * \file
 *  Driver for the Sensortag TI TMP007 infrared thermophile sensor
 */
/*---------------------------------------------------------------------------*/
#include "contiki.h"
#include "lib/sensors.h"
#include "tmp-007-sensor.h"
#include "sys/ctimer.h"
#include "board-i2c.h"
#include "sensor-common.h"
#include "ti-lib.h"
 
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
/*---------------------------------------------------------------------------*/
#define DEBUG 0
#if DEBUG
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
/* Slave address */
#define SENSOR_I2C_ADDRESS              0x44
/*---------------------------------------------------------------------------*/
/* TMP007 register addresses */
#define TMP007_REG_ADDR_VOLTAGE         0x00
#define TMP007_REG_ADDR_LOCAL_TEMP      0x01
#define TMP007_REG_ADDR_CONFIG          0x02
#define TMP007_REG_ADDR_OBJ_TEMP        0x03
#define TMP007_REG_ADDR_STATUS          0x04
#define TMP007_REG_PROD_ID              0x1F
/*---------------------------------------------------------------------------*/
/* TMP007 register values */
#define TMP007_VAL_CONFIG_ON            0x1000  /* Sensor on state */
#define TMP007_VAL_CONFIG_OFF           0x0000  /* Sensor off state */
#define TMP007_VAL_CONFIG_RESET         0x8000
#define TMP007_VAL_PROD_ID              0x0078  /* Product ID */
/*---------------------------------------------------------------------------*/
/* Conversion ready (status register) bit values */
#define CONV_RDY_BIT                    0x4000
/*---------------------------------------------------------------------------*/
/* Register length */
#define REGISTER_LENGTH                 2
/*---------------------------------------------------------------------------*/
/* Sensor data size */
#define DATA_SIZE                       4
/*---------------------------------------------------------------------------*/
/* Byte swap of 16-bit register value */
#define HI_UINT16(a) (((a) >> 8) & 0xFF)
#define LO_UINT16(a) ((a) & 0xFF)
 
#define SWAP(v) ((LO_UINT16(v) << 8) | HI_UINT16(v))
/*---------------------------------------------------------------------------*/
#define SELECT() board_i2c_select(BOARD_I2C_INTERFACE_0, SENSOR_I2C_ADDRESS)
/*---------------------------------------------------------------------------*/
static uint8_t buf[DATA_SIZE];
static uint16_t val;
/*---------------------------------------------------------------------------*/
#define SENSOR_STATUS_DISABLED     0
#define SENSOR_STATUS_INITIALISED  1
#define SENSOR_STATUS_NOT_READY    2
#define SENSOR_STATUS_READY        3
 
static int enabled = SENSOR_STATUS_DISABLED;
/*---------------------------------------------------------------------------*/
/* Wait SENSOR_STARTUP_DELAY clock ticks for the sensor to be ready - 275ms */
#define SENSOR_STARTUP_DELAY 36
 
static struct ctimer startup_timer;
/*---------------------------------------------------------------------------*/
/* Latched values */
static int obj_temp_latched;
static int amb_temp_latched;
/*---------------------------------------------------------------------------*/
static void
notify_ready(void *not_used)
{
  enabled = SENSOR_STATUS_READY;
  sensors_changed(&tmp_007_sensor);
}
/*---------------------------------------------------------------------------*/
/**
 * \brief Turn the sensor on/off
 */
static bool
enable_sensor(bool enable)
{
  bool success;
 
  SELECT();
 
  if(enable) {
    val = TMP007_VAL_CONFIG_ON;
  } else {
    val = TMP007_VAL_CONFIG_OFF;
  }
  val = SWAP(val);
 
  success = sensor_common_write_reg(TMP007_REG_ADDR_CONFIG, (uint8_t *)&val,
                                    REGISTER_LENGTH);
 
  return success;
}
/*---------------------------------------------------------------------------*/
/**
 * \brief Read the sensor value registers
 * \param raw_temp Temperature in 16 bit format
 * \param raw_obj_temp object temperature in 16 bit format
 * \return TRUE if valid data could be retrieved
 */
static bool
read_data(uint16_t *raw_temp, uint16_t *raw_obj_temp)
{
  bool success;
 
  SELECT();
 
  success = sensor_common_read_reg(TMP007_REG_ADDR_STATUS, (uint8_t *)&val,
                                   REGISTER_LENGTH);
 
  if(success) {
    val = SWAP(val);
    success = val & CONV_RDY_BIT;
  }
 
  if(success) {
    success = sensor_common_read_reg(TMP007_REG_ADDR_LOCAL_TEMP, &buf[0],
                                     REGISTER_LENGTH);
    if(success) {
      success = sensor_common_read_reg(TMP007_REG_ADDR_OBJ_TEMP, &buf[2],
                                       REGISTER_LENGTH);
    }
  }
 
  if(!success) {
    sensor_common_set_error_data(buf, 4);
  }
 
  /* Swap byte order */
  *raw_temp = buf[0] << 8 | buf[1];
  *raw_obj_temp = buf[2] << 8 | buf[3];
 
  return success;
}
/*---------------------------------------------------------------------------*/
/**
 * \brief Convert raw data to values in degrees C
 * \param raw_temp raw ambient temperature from sensor
 * \param raw_obj_temp raw object temperature from sensor
 * \param obj converted object temperature
 * \param amb converted ambient temperature
 */
static void
convert(uint16_t raw_temp, uint16_t raw_obj_temp, float *obj, float *amb)
{
  const float SCALE_LSB = 0.03125;
  float t;
  int it;
 
  it = (int)((raw_obj_temp) >> 2);
  t = ((float)(it)) * SCALE_LSB;
  *obj = t;
 
  it = (int)((raw_temp) >> 2);
  t = (float)it;
  *amb = t * SCALE_LSB;
}
/*---------------------------------------------------------------------------*/
/**
 * \brief Returns a reading from the sensor
 * \param type TMP_007_SENSOR_TYPE_OBJECT or TMP_007_SENSOR_TYPE_AMBIENT
 * \return Object or Ambient temperature in milli degrees C
 */
static int
value(int type)
{
  int rv;
  uint16_t raw_temp;
  uint16_t raw_obj_temp;
  float obj_temp;
  float amb_temp;
 
  if(enabled != SENSOR_STATUS_READY) {
    PRINTF("Sensor disabled or starting up (%d)\n", enabled);
    return CC26XX_SENSOR_READING_ERROR;
  }
 
  if((type & TMP_007_SENSOR_TYPE_ALL) == 0) {
    PRINTF("Invalid type\n");
    return CC26XX_SENSOR_READING_ERROR;
  }
 
  rv = CC26XX_SENSOR_READING_ERROR;
 
  if(type == TMP_007_SENSOR_TYPE_ALL) {
    rv = read_data(&raw_temp, &raw_obj_temp);
 
    if(rv == 0) {
      return CC26XX_SENSOR_READING_ERROR;
    }
 
    convert(raw_temp, raw_obj_temp, &obj_temp, &amb_temp);
    PRINTF("TMP: %04X %04X       o=%d a=%d\n", raw_temp, raw_obj_temp,
           (int)(obj_temp * 1000), (int)(amb_temp * 1000));
 
    obj_temp_latched = (int)(obj_temp * 1000);
    amb_temp_latched = (int)(amb_temp * 1000);
    rv = 1;
  } else if(type == TMP_007_SENSOR_TYPE_OBJECT) {
    rv = obj_temp_latched;
  } else if(type == TMP_007_SENSOR_TYPE_AMBIENT) {
    rv = amb_temp_latched;
  }
 
  return rv;
}
/*---------------------------------------------------------------------------*/
/**
 * \brief Configuration function for the TMP007 sensor.
 *
 * \param type Activate, enable or disable the sensor. See below
 * \param enable
 *
 * When type == SENSORS_HW_INIT we turn on the hardware
 * When type == SENSORS_ACTIVE and enable==1 we enable the sensor
 * When type == SENSORS_ACTIVE and enable==0 we disable the sensor
 */
static int
configure(int type, int enable)
{
  switch(type) {
  case SENSORS_HW_INIT:
    ti_lib_ioc_pin_type_gpio_input(BOARD_IOID_TMP_RDY);
    ti_lib_ioc_io_port_pull_set(BOARD_IOID_TMP_RDY, IOC_IOPULL_UP);
    ti_lib_ioc_io_hyst_set(BOARD_IOID_TMP_RDY, IOC_HYST_ENABLE);
 
    enable_sensor(false);
    enabled = SENSOR_STATUS_INITIALISED;
    break;
  case SENSORS_ACTIVE:
    /* Must be initialised first */
    if(enabled == SENSOR_STATUS_DISABLED) {
      return SENSOR_STATUS_DISABLED;
    }
    if(enable) {
      enable_sensor(true);
      ctimer_set(&startup_timer, SENSOR_STARTUP_DELAY, notify_ready, NULL);
      enabled = SENSOR_STATUS_NOT_READY;
    } else {
      ctimer_stop(&startup_timer);
      enable_sensor(false);
      enabled = SENSOR_STATUS_INITIALISED;
    }
    break;
  default:
    break;
  }
  return enabled;
}
/*---------------------------------------------------------------------------*/
/**
 * \brief Returns the status of the sensor
 * \param type SENSORS_ACTIVE or SENSORS_READY
 * \return 1 if the sensor is enabled
 */
static int
status(int type)
{
  switch(type) {
  case SENSORS_ACTIVE:
  case SENSORS_READY:
    return enabled;
    break;
  default:
    break;
  }
  return SENSOR_STATUS_DISABLED;
}
/*---------------------------------------------------------------------------*/
SENSORS_SENSOR(tmp_007_sensor, "TMP007", value, configure, status);
/*---------------------------------------------------------------------------*/
/** @} */