nuttx/drivers/sensors/bmp280.c

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/****************************************************************************
* drivers/sensors/bmp280.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/nuttx.h>
#include <stdlib.h>
#include <fixedmath.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/sensors/bmp280.h>
#include <nuttx/sensors/sensor.h>
#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_BMP280)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define BMP280_ADDR 0x76
#define BMP280_FREQ CONFIG_BMP280_I2C_FREQUENCY
#define DEVID 0x58
#define BMP280_DIG_T1_LSB 0x88
#define BMP280_DIG_T1_MSB 0x89
#define BMP280_DIG_T2_LSB 0x8a
#define BMP280_DIG_T2_MSB 0x8b
#define BMP280_DIG_T3_LSB 0x8c
#define BMP280_DIG_T3_MSB 0x8d
#define BMP280_DIG_P1_LSB 0x8e
#define BMP280_DIG_P1_MSB 0x8f
#define BMP280_DIG_P2_LSB 0x90
#define BMP280_DIG_P2_MSB 0x91
#define BMP280_DIG_P3_LSB 0x92
#define BMP280_DIG_P3_MSB 0x93
#define BMP280_DIG_P4_LSB 0x94
#define BMP280_DIG_P4_MSB 0x95
#define BMP280_DIG_P5_LSB 0x96
#define BMP280_DIG_P5_MSB 0x97
#define BMP280_DIG_P6_LSB 0x98
#define BMP280_DIG_P6_MSB 0x99
#define BMP280_DIG_P7_LSB 0x9a
#define BMP280_DIG_P7_MSB 0x9b
#define BMP280_DIG_P8_LSB 0x9c
#define BMP280_DIG_P8_MSB 0x9d
#define BMP280_DIG_P9_LSB 0x9e
#define BMP280_DIG_P9_MSB 0x9f
#define BMP280_DEVID 0xd0
#define BMP280_SOFT_RESET 0xe0
#define BMP280_STAT 0xf3
#define BMP280_CTRL_MEAS 0xf4
#define BMP280_CONFIG 0xf5
#define BMP280_PRESS_MSB 0xf7
#define BMP280_PRESS_LSB 0xf8
#define BMP280_PRESS_XLSB 0xf9
#define BMP280_TEMP_MSB 0xfa
#define BMP280_TEMP_LSB 0xfb
#define BMP280_TEMP_XLSB 0xfc
/* Power modes */
#define BMP280_SLEEP_MODE (0x00)
#define BMP280_FORCED_MODE (0x01)
#define BMP280_NORMAL_MODE (0x03)
/* Oversampling for temperature. */
#define BMP280_OST_SKIPPED (0x00 << 5)
#define BMP280_OST_X1 (0x01 << 5)
#define BMP280_OST_X2 (0x02 << 5)
#define BMP280_OST_X4 (0x03 << 5)
#define BMP280_OST_X8 (0x04 << 5)
#define BMP280_OST_X16 (0x05 << 5)
/* Oversampling for pressure. */
#define BMP280_OSP_SKIPPED (0x00 << 2)
#define BMP280_OSP_X1 (0x01 << 2)
#define BMP280_OSP_X2 (0x02 << 2)
#define BMP280_OSP_X4 (0x03 << 2)
#define BMP280_OSP_X8 (0x04 << 2)
#define BMP280_OSP_X16 (0x05 << 2)
/* Predefined oversampling combinations. */
#define BMP280_OS_ULTRA_HIGH_RES (BMP280_OSP_X16 | BMP280_OST_X2)
#define BMP280_OS_STANDARD_RES (BMP280_OSP_X4 | BMP280_OST_X1)
#define BMP280_OS_ULTRA_LOW_POWER (BMP280_OSP_X1 | BMP280_OST_X1)
/* Data combined from bytes to int */
#define COMBINE(d) (((int)(d)[0] << 12) | ((int)(d)[1] << 4) | ((int)(d)[2] >> 4))
/****************************************************************************
* Private Type Definitions
****************************************************************************/
struct bmp280_dev_s
{
FAR struct sensor_lowerhalf_s sensor_lower;
FAR struct i2c_master_s *i2c; /* I2C interface */
uint8_t addr; /* BMP280 I2C address */
int freq; /* BMP280 Frequency <= 3.4MHz */
bool activated;
struct bmp280_calib_s
{
uint16_t t1;
int16_t t2;
int16_t t3;
uint16_t p1;
int16_t p2;
int16_t p3;
int16_t p4;
int16_t p5;
int16_t p6;
int16_t p7;
int16_t p8;
int16_t p9;
} calib;
int32_t tempfine;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
2020-06-15 23:45:34 +02:00
static uint8_t bmp280_getreg8(FAR struct bmp280_dev_s *priv,
uint8_t regaddr);
static int bmp280_putreg8(FAR struct bmp280_dev_s *priv, uint8_t regaddr,
uint8_t regval);
/* Sensor methods */
static int bmp280_set_interval(FAR struct sensor_lowerhalf_s *lower,
FAR unsigned long *period_us);
static int bmp280_activate(FAR struct sensor_lowerhalf_s *lower,
bool enable);
static int bmp280_fetch(FAR struct sensor_lowerhalf_s *lower,
FAR char *buffer, size_t buflen);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct sensor_ops_s g_sensor_ops =
{
.activate = bmp280_activate,
.fetch = bmp280_fetch,
.set_interval = bmp280_set_interval,
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: bmp280_getreg8
*
* Description:
* Read from an 8-bit BMP280 register
*
****************************************************************************/
static uint8_t bmp280_getreg8(FAR struct bmp280_dev_s *priv, uint8_t regaddr)
{
struct i2c_msg_s msg[2];
uint8_t regval = 0;
int ret;
msg[0].frequency = priv->freq;
msg[0].addr = priv->addr;
msg[0].flags = 0;
msg[0].buffer = &regaddr;
msg[0].length = 1;
msg[1].frequency = priv->freq;
msg[1].addr = priv->addr;
msg[1].flags = I2C_M_READ;
msg[1].buffer = &regval;
msg[1].length = 1;
ret = I2C_TRANSFER(priv->i2c, msg, 2);
if (ret < 0)
{
snerr("I2C_TRANSFER failed: %d\n", ret);
return 0;
}
return regval;
}
/****************************************************************************
* Name: bmp280_getregs
*
* Description:
* Read two 8-bit from a BMP280 register
*
****************************************************************************/
static int bmp280_getregs(FAR struct bmp280_dev_s *priv, uint8_t regaddr,
uint8_t *rxbuffer, uint8_t length)
{
struct i2c_msg_s msg[2];
int ret;
msg[0].frequency = priv->freq;
msg[0].addr = priv->addr;
msg[0].flags = 0;
msg[0].buffer = &regaddr;
msg[0].length = 1;
msg[1].frequency = priv->freq;
msg[1].addr = priv->addr;
msg[1].flags = I2C_M_READ;
msg[1].buffer = rxbuffer;
msg[1].length = length;
ret = I2C_TRANSFER(priv->i2c, msg, 2);
if (ret < 0)
{
snerr("I2C_TRANSFER failed: %d\n", ret);
return -1;
}
return OK;
}
/****************************************************************************
* Name: bmp280_putreg8
*
* Description:
* Write to an 8-bit BMP280 register
*
****************************************************************************/
static int bmp280_putreg8(FAR struct bmp280_dev_s *priv, uint8_t regaddr,
uint8_t regval)
{
struct i2c_msg_s msg[2];
uint8_t txbuffer[2];
int ret;
txbuffer[0] = regaddr;
txbuffer[1] = regval;
msg[0].frequency = priv->freq;
msg[0].addr = priv->addr;
msg[0].flags = 0;
msg[0].buffer = txbuffer;
msg[0].length = 2;
ret = I2C_TRANSFER(priv->i2c, msg, 1);
if (ret < 0)
{
snerr("I2C_TRANSFER failed: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: bmp280_checkid
*
* Description:
* Read and verify the BMP280 chip ID
*
****************************************************************************/
static int bmp280_checkid(FAR struct bmp280_dev_s *priv)
{
uint8_t devid = 0;
/* Read device ID */
devid = bmp280_getreg8(priv, BMP280_DEVID);
up_mdelay(1);
sninfo("devid: 0x%02x\n", devid);
if (devid != (uint16_t) DEVID)
{
/* ID is not Correct */
snerr("Wrong Device ID! %02x\n", devid);
return -ENODEV;
}
return OK;
}
/****************************************************************************
* Name: bmp280_set_standby
*
* Description:
* set standby duration
*
****************************************************************************/
static int bmp280_set_standby(FAR struct bmp280_dev_s *priv, uint8_t value)
{
uint8_t v_data_u8;
uint8_t v_sb_u8;
/* Set the standby duration value */
v_data_u8 = bmp280_getreg8(priv, BMP280_CONFIG);
v_data_u8 = (v_data_u8 & ~(0x07 << 5)) | (value << 5);
bmp280_putreg8(priv, BMP280_CONFIG, v_data_u8);
/* Check the standby duration value */
v_data_u8 = bmp280_getreg8(priv, BMP280_CONFIG);
v_sb_u8 = (v_data_u8 >> 5) & 0x07;
if (v_sb_u8 != value)
{
snerr("Failed to set value for standby time.");
return ERROR;
}
return OK;
}
/****************************************************************************
* Name: bmp280_initialize
*
* Description:
* Initialize BMP280 device
*
****************************************************************************/
static int bmp280_initialize(FAR struct bmp280_dev_s *priv)
{
uint8_t buf[24];
int ret;
/* Get calibration data. */
ret = bmp280_getregs(priv, BMP280_DIG_T1_LSB, buf, 24);
if (ret < 0)
{
return ret;
}
priv->calib.t1 = (uint16_t)buf[1] << 8 | buf[0];
priv->calib.t2 = (int16_t) buf[3] << 8 | buf[2];
priv->calib.t3 = (int16_t) buf[5] << 8 | buf[4];
priv->calib.p1 = (uint16_t)buf[7] << 8 | buf[6];
priv->calib.p2 = (int16_t) buf[9] << 8 | buf[8];
priv->calib.p3 = (int16_t) buf[11] << 8 | buf[10];
priv->calib.p4 = (int16_t) buf[13] << 8 | buf[12];
priv->calib.p5 = (int16_t) buf[15] << 8 | buf[14];
priv->calib.p6 = (int16_t) buf[17] << 8 | buf[16];
priv->calib.p7 = (int16_t) buf[19] << 8 | buf[18];
priv->calib.p8 = (int16_t) buf[21] << 8 | buf[20];
priv->calib.p9 = (int16_t) buf[23] << 8 | buf[22];
sninfo("T1 = %u\n", priv->calib.t1);
sninfo("T2 = %d\n", priv->calib.t2);
sninfo("T3 = %d\n", priv->calib.t3);
sninfo("P1 = %u\n", priv->calib.p1);
sninfo("P2 = %d\n", priv->calib.p2);
sninfo("P3 = %d\n", priv->calib.p3);
sninfo("P4 = %d\n", priv->calib.p4);
sninfo("P5 = %d\n", priv->calib.p5);
sninfo("P6 = %d\n", priv->calib.p6);
sninfo("P7 = %d\n", priv->calib.p7);
sninfo("P8 = %d\n", priv->calib.p8);
sninfo("P9 = %d\n", priv->calib.p9);
/* Set power mode to sleep */
bmp280_putreg8(priv, BMP280_CTRL_MEAS, BMP280_SLEEP_MODE);
/* Set stand-by time to 0.5 ms, no IIR filter */
ret = bmp280_set_standby(priv, BMP280_STANDBY_05_MS);
if (ret != OK)
{
snerr("Failed to set value for standby time.\n");
return -1;
}
return ret;
}
/****************************************************************************
* Name: bmp280_compensate
*
* Description:
* calculate compensate tempreture
*
* Input Parameters:
* temp - uncompensate value of tempreture.
*
* Returned Value:
* calculate result of compensate tempreture.
*
****************************************************************************/
static int32_t bmp280_compensate_temp(FAR struct bmp280_dev_s *priv,
int32_t temp)
{
struct bmp280_calib_s *c = &priv->calib;
int32_t var1;
int32_t var2;
var1 = ((((temp >> 3) - ((int32_t)c->t1 << 1))) * ((int32_t)c->t2)) >> 11;
var2 = (((((temp >> 4) - ((int32_t)c->t1)) *
((temp >> 4) - ((int32_t)c->t1))) >> 12) *
((int32_t)c->t3)) >> 14;
priv->tempfine = var1 + var2;
return (priv->tempfine * 5 + 128) >> 8;
}
/****************************************************************************
* Name: bmp280_compensate_press
*
* Description:
* calculate compensate pressure
*
* Input Parameters:
* press - uncompensate value of pressure.
*
* Returned Value:
* calculate result of compensate pressure.
*
****************************************************************************/
static uint32_t bmp280_compensate_press(FAR struct bmp280_dev_s *priv,
uint32_t press)
{
struct bmp280_calib_s *c = &priv->calib;
int32_t var1;
int32_t var2;
uint32_t p;
var1 = (priv->tempfine >> 1) - 64000;
var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * ((int32_t)c->p6);
var2 = var2 + ((var1 * ((int32_t)c->p5)) << 1);
var2 = (var2 >> 2) + (((int32_t)c->p4) << 16);
var1 = (((c->p3 * (((var1 >> 2) * (var1 >> 2)) >> 13)) >> 3) +
((((int32_t)c->p2) * var1) >> 1)) >> 18;
var1 = (((32768 + var1) * ((int32_t)c->p1)) >> 15);
/* avoid exception caused by division by zero */
if (var1 == 0)
{
return 0;
}
p = (((uint32_t)((0x100000) - press) - (var2 >> 12))) * 3125;
if (p < 0x80000000)
{
p = (p << 1) / ((uint32_t)var1);
}
else
{
p = (p / (uint32_t)var1) * 2;
}
var1 = ((int32_t)c->p9 * ((int32_t)(((p >> 3) * (p >> 3)) >> 13))) >> 12;
var2 = ((int32_t)(p >> 2) * c->p8) >> 13;
p = (uint32_t)((int32_t)p + ((var1 + var2 + c->p7) >> 4));
return p;
}
/****************************************************************************
* Name: bmp280_set_interval
****************************************************************************/
static int bmp280_set_interval(FAR struct sensor_lowerhalf_s *lower,
FAR unsigned long *period_us)
{
FAR struct bmp280_dev_s *priv = container_of(lower,
FAR struct bmp280_dev_s,
sensor_lower);
int ret = 0;
uint8_t regval;
switch (*period_us)
{
case 500:
regval = BMP280_STANDBY_05_MS;
break;
case 62500:
regval = BMP280_STANDBY_63_MS;
break;
case 125000:
regval = BMP280_STANDBY_125_MS;
break;
case 250000:
regval = BMP280_STANDBY_250_MS;
break;
case 500000:
regval = BMP280_STANDBY_500_MS;
break;
case 1000000:
regval = BMP280_STANDBY_1000_MS;
break;
case 2000000:
regval = BMP280_STANDBY_2000_MS;
break;
case 4000000:
regval = BMP280_STANDBY_4000_MS;
break;
default:
ret = -EINVAL;
break;
}
if (ret == 0)
{
ret = bmp280_set_standby(priv, regval);
}
return ret;
}
/****************************************************************************
* Name: bmp280_activate
****************************************************************************/
static int bmp280_activate(FAR struct sensor_lowerhalf_s *lower,
bool enable)
{
FAR struct bmp280_dev_s *priv = container_of(lower,
FAR struct bmp280_dev_s,
sensor_lower);
int ret;
if (enable)
{
/* Set power mode to normal and standard sampling resolution. */
ret = bmp280_putreg8(priv, BMP280_CTRL_MEAS, BMP280_NORMAL_MODE |
BMP280_OS_STANDARD_RES);
}
else
{
/* Set to sleep mode */
ret = bmp280_putreg8(priv, BMP280_CTRL_MEAS, BMP280_SLEEP_MODE);
}
if (ret >= 0)
2020-06-15 23:45:34 +02:00
{
priv->activated = enable;
2020-06-15 23:45:34 +02:00
}
return ret;
}
/****************************************************************************
* Name: bmp280_fetch
****************************************************************************/
static int bmp280_fetch(FAR struct sensor_lowerhalf_s *lower,
FAR char *buffer, size_t buflen)
{
FAR struct bmp280_dev_s *priv = container_of(lower,
FAR struct bmp280_dev_s,
sensor_lower);
uint8_t buf[6];
uint32_t press;
int32_t temp;
int ret;
struct timespec ts;
struct sensor_event_baro baro_data;
if (buflen != sizeof(baro_data))
{
return -EINVAL;
}
if (!priv->activated)
{
/* Sensor is asleep, go to force mode to read once */
ret = bmp280_putreg8(priv, BMP280_CTRL_MEAS, BMP280_FORCED_MODE |
BMP280_OS_ULTRA_LOW_POWER);
if (ret < 0)
{
return ret;
}
/* Wait time according to ultra low power mode set during sleep */
up_mdelay(6);
}
/* Read pressure & data */
ret = bmp280_getregs(priv, BMP280_PRESS_MSB, buf, 6);
if (ret < 0)
{
return ret;
}
press = (uint32_t)COMBINE(buf);
temp = COMBINE(&buf[3]);
sninfo("press = %"PRIu32", temp = %"PRIi32"\n", press, temp);
temp = bmp280_compensate_temp(priv, temp);
press = bmp280_compensate_press(priv, press);
clock_systime_timespec(&ts);
baro_data.timestamp = 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
baro_data.pressure = press / 100.0f;
baro_data.temperature = temp / 100.0f;
memcpy(buffer, &baro_data, sizeof(baro_data));
return buflen;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: bmp280_register
*
* Description:
* Register the BMP280 character device
*
* Input Parameters:
* devno - Instance number for driver
* i2c - An instance of the I2C interface to use to communicate with
* BMP280
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int bmp280_register(int devno, FAR struct i2c_master_s *i2c)
{
FAR struct bmp280_dev_s *priv;
int ret;
/* Initialize the BMP280 device structure */
priv = (FAR struct bmp280_dev_s *)kmm_zalloc(sizeof(struct bmp280_dev_s));
if (!priv)
{
snerr("Failed to allocate instance\n");
return -ENOMEM;
}
priv->i2c = i2c;
priv->addr = BMP280_ADDR;
priv->freq = BMP280_FREQ;
priv->sensor_lower.ops = &g_sensor_ops;
priv->sensor_lower.type = SENSOR_TYPE_BAROMETER;
/* Check Device ID */
ret = bmp280_checkid(priv);
if (ret < 0)
{
snerr("Failed to register driver: %d\n", ret);
kmm_free(priv);
return ret;
}
ret = bmp280_initialize(priv);
if (ret < 0)
{
snerr("Failed to initialize physical device bmp280:%d\n", ret);
kmm_free(priv);
return ret;
}
/* Register the character driver */
ret = sensor_register(&priv->sensor_lower, devno);
if (ret < 0)
{
snerr("Failed to register driver: %d\n", ret);
kmm_free(priv);
}
sninfo("BMP280 driver loaded successfully!\n");
return ret;
}
#endif