mirror of
https://github.com/RIOT-OS/RIOT.git
synced 2024-12-29 04:50:03 +01:00
251 lines
8.0 KiB
C
251 lines
8.0 KiB
C
/*
|
|
* Copyright (C) 2016 Inria
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU Lesser
|
|
* General Public License v2.1. See the file LICENSE in the top level
|
|
* directory for more details.
|
|
*/
|
|
|
|
/**
|
|
* @ingroup drivers_bmp180
|
|
* @{
|
|
*
|
|
* @file
|
|
* @brief Device driver implementation for the BMP180/BMP085 temperature and pressure sensor.
|
|
*
|
|
* @author Alexandre Abadie <alexandre.abadie@inria.fr>
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
#include <math.h>
|
|
|
|
#include "log.h"
|
|
#include "bmp180.h"
|
|
#include "bmp180_internals.h"
|
|
#include "bmp180_params.h"
|
|
#include "periph/i2c.h"
|
|
#include "ztimer.h"
|
|
|
|
#define ENABLE_DEBUG 0
|
|
#include "debug.h"
|
|
|
|
#define DEV_I2C (dev->params.i2c_dev)
|
|
#define DEV_ADDR (dev->params.i2c_addr)
|
|
#define OVERSAMPLING (dev->params.oversampling)
|
|
|
|
/* Internal function prototypes */
|
|
static int _read_ut(const bmp180_t *dev, int32_t *ut);
|
|
static int _read_up(const bmp180_t *dev, int32_t *up);
|
|
static int _compute_b5(const bmp180_t *dev, int32_t ut, int32_t *b5);
|
|
|
|
/*---------------------------------------------------------------------------*
|
|
* BMP180 Core API *
|
|
*---------------------------------------------------------------------------*/
|
|
|
|
int bmp180_init(bmp180_t *dev, const bmp180_params_t *params)
|
|
{
|
|
dev->params = *params;
|
|
|
|
/* Clamp oversampling mode */
|
|
if (OVERSAMPLING > BMP180_ULTRAHIGHRES) {
|
|
OVERSAMPLING = BMP180_ULTRAHIGHRES;
|
|
}
|
|
|
|
/* Acquire exclusive access */
|
|
i2c_acquire(DEV_I2C);
|
|
|
|
/* Check sensor ID */
|
|
uint8_t checkid;
|
|
i2c_read_reg(DEV_I2C, DEV_ADDR, BMP180_REGISTER_ID, &checkid, 0);
|
|
if (checkid != 0x55) {
|
|
DEBUG("[Error] Wrong device ID\n");
|
|
i2c_release(DEV_I2C);
|
|
return -BMP180_ERR_NODEV;
|
|
}
|
|
|
|
/* adding delay before reading calibration values to avoid timing issues */
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_ULTRALOWPOWER_DELAY_MS);
|
|
|
|
uint8_t buffer[22] = {0};
|
|
/* Read calibration values, using contiguous register addresses */
|
|
if (i2c_read_regs(DEV_I2C, DEV_ADDR, BMP180_CALIBRATION_AC1,
|
|
buffer, 22, 0) < 0) {
|
|
DEBUG("[Error] Cannot read calibration registers.\n");
|
|
i2c_release(DEV_I2C);
|
|
return -BMP180_ERR_NOCAL;
|
|
}
|
|
dev->calibration.ac1 = (int16_t)(buffer[0] << 8) | buffer[1];
|
|
dev->calibration.ac2 = (int16_t)(buffer[2] << 8) | buffer[3];
|
|
dev->calibration.ac3 = (int16_t)(buffer[4] << 8) | buffer[4];
|
|
dev->calibration.ac4 = (uint16_t)(buffer[6] << 8) | buffer[7];
|
|
dev->calibration.ac5 = (uint16_t)(buffer[8] << 8) | buffer[9];
|
|
dev->calibration.ac6 = (uint16_t)(buffer[10] << 8) | buffer[11];
|
|
dev->calibration.b1 = (int16_t)(buffer[12] << 8) | buffer[13];
|
|
dev->calibration.b2 = (int16_t)(buffer[14] << 8) | buffer[15];
|
|
dev->calibration.mb = (int16_t)(buffer[16] << 8) | buffer[17];
|
|
dev->calibration.mc = (int16_t)(buffer[18] << 8) | buffer[19];
|
|
dev->calibration.md = (int16_t)(buffer[20] << 8) | buffer[21];
|
|
|
|
/* Release I2C device */
|
|
i2c_release(DEV_I2C);
|
|
|
|
DEBUG("AC1: %i\n", (int)dev->calibration.ac1);
|
|
DEBUG("AC2: %i\n", (int)dev->calibration.ac2);
|
|
DEBUG("AC3: %i\n", (int)dev->calibration.ac3);
|
|
DEBUG("AC4: %i\n", (int)dev->calibration.ac4);
|
|
DEBUG("AC5: %i\n", (int)dev->calibration.ac5);
|
|
DEBUG("AC6: %i\n", (int)dev->calibration.ac6);
|
|
DEBUG("B1: %i\n", (int)dev->calibration.b1);
|
|
DEBUG("B2: %i\n", (int)dev->calibration.b2);
|
|
DEBUG("MB: %i\n", (int)dev->calibration.mb);
|
|
DEBUG("MC: %i\n", (int)dev->calibration.mc);
|
|
DEBUG("MD: %i\n", (int)dev->calibration.md);
|
|
return 0;
|
|
}
|
|
|
|
int16_t bmp180_read_temperature(const bmp180_t *dev)
|
|
{
|
|
int32_t ut = 0, b5;
|
|
/* Acquire exclusive access */
|
|
i2c_acquire(DEV_I2C);
|
|
|
|
/* Read uncompensated value */
|
|
_read_ut(dev, &ut);
|
|
|
|
/* Release I2C device */
|
|
i2c_release(DEV_I2C);
|
|
|
|
/* Compute true temperature value following datasheet formulas */
|
|
_compute_b5(dev, ut, &b5);
|
|
|
|
return (int16_t)((b5 + 8) >> 4);
|
|
}
|
|
|
|
uint32_t bmp180_read_pressure(const bmp180_t *dev)
|
|
{
|
|
int32_t ut = 0, up = 0, x1, x2, x3, b3, b5, b6, p;
|
|
uint32_t b4, b7;
|
|
|
|
/* Acquire exclusive access */
|
|
i2c_acquire(DEV_I2C);
|
|
|
|
/* Read uncompensated values: first temperature, second pressure */
|
|
_read_ut(dev, &ut);
|
|
_read_up(dev, &up);
|
|
|
|
/* release I2C device */
|
|
i2c_release(DEV_I2C);
|
|
|
|
/* Compute true pressure value following datasheet formulas */
|
|
_compute_b5(dev, ut, &b5);
|
|
b6 = b5 - 4000;
|
|
x1 = ((int32_t)dev->calibration.b2 * ((b6 * b6) >> 12)) >> 11;
|
|
x2 = ((int32_t)dev->calibration.ac2 * b6) >> 11;
|
|
x3 = x1 + x2;
|
|
b3 = ((((int32_t)dev->calibration.ac1*4 + x3) << OVERSAMPLING) + 2) >> 2;
|
|
x1 = ((int32_t)dev->calibration.ac3 * b6) >> 13;
|
|
x2 = ((int32_t)dev->calibration.b1 * (b6 * b6) >> 12) >> 16;
|
|
x3 = ((x1 + x2) + 2) >> 2;
|
|
b4 = ((uint32_t)dev->calibration.ac4 * (uint32_t)(x3 + 32768)) >> 15;
|
|
b7 = (uint32_t)(up - b3) * (uint32_t)(50000UL >> OVERSAMPLING);
|
|
if (b7 < 0x80000000) {
|
|
p = (b7 * 2) / b4;
|
|
}
|
|
else {
|
|
p = (b7 / b4) * 2;
|
|
}
|
|
|
|
x1 = (p >> 8) * (p >> 8);
|
|
x1 = (x1 * 3038) >> 16;
|
|
x2 = (-7357 * p) >> 16;
|
|
|
|
return (uint32_t)(p + ((x1 + x2 + 3791) >> 4));
|
|
}
|
|
|
|
int16_t bmp180_altitude(const bmp180_t *dev, uint32_t pressure_0)
|
|
{
|
|
uint32_t p = bmp180_read_pressure(dev);
|
|
|
|
return (int16_t)(44330.0 * (1.0 - pow((double)p / pressure_0, 0.1903)));;
|
|
}
|
|
|
|
uint32_t bmp180_sealevel_pressure(const bmp180_t *dev, int16_t altitude)
|
|
{
|
|
uint32_t p = bmp180_read_pressure(dev);
|
|
|
|
return (uint32_t)((double)p / pow(1.0 - (altitude / 44330.0), 5.255));;
|
|
}
|
|
|
|
/*------------------------------------------------------------------------------------*/
|
|
/* Internal functions */
|
|
/*------------------------------------------------------------------------------------*/
|
|
|
|
static int _read_ut(const bmp180_t *dev, int32_t *output)
|
|
{
|
|
/* Read UT (Uncompsensated Temperature value) */
|
|
uint8_t ut[2] = {0};
|
|
uint8_t control[2] = { BMP180_REGISTER_CONTROL, BMP180_TEMPERATURE_COMMAND };
|
|
i2c_write_bytes(DEV_I2C, DEV_ADDR, control, 2, 0);
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_ULTRALOWPOWER_DELAY_MS);
|
|
if (i2c_read_regs(DEV_I2C, DEV_ADDR, BMP180_REGISTER_DATA, ut, 2, 0) < 0) {
|
|
DEBUG("[Error] Cannot read uncompensated temperature.\n");
|
|
i2c_release(DEV_I2C);
|
|
return -1;
|
|
}
|
|
*output = ((uint16_t)ut[0] << 8) | ut[1];
|
|
|
|
DEBUG("UT: %i\n", (int)*output);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int _read_up(const bmp180_t *dev, int32_t *output)
|
|
{
|
|
/* Read UP (Uncompsensated Pressure value) */
|
|
uint8_t up[3] = {0};
|
|
uint8_t control[2] = { BMP180_REGISTER_CONTROL,
|
|
BMP180_PRESSURE_COMMAND | (OVERSAMPLING & 0x3) << 6 };
|
|
i2c_write_bytes(DEV_I2C, DEV_ADDR, control, 2, 0);
|
|
switch (OVERSAMPLING) {
|
|
case BMP180_ULTRALOWPOWER:
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_ULTRALOWPOWER_DELAY_MS);
|
|
break;
|
|
case BMP180_STANDARD:
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_STANDARD_DELAY_MS);
|
|
break;
|
|
case BMP180_HIGHRES:
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_HIGHRES_DELAY_MS);
|
|
break;
|
|
case BMP180_ULTRAHIGHRES:
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_ULTRAHIGHRES_DELAY_MS);
|
|
break;
|
|
default:
|
|
ztimer_sleep(ZTIMER_MSEC, BMP180_ULTRALOWPOWER_DELAY_MS);
|
|
break;
|
|
}
|
|
if (i2c_read_regs(DEV_I2C, DEV_ADDR, BMP180_REGISTER_DATA, up, 3, 0) < 0) {
|
|
DEBUG("[Error] Cannot read uncompensated pressure.\n");
|
|
i2c_release(DEV_I2C);
|
|
return -1;
|
|
}
|
|
|
|
*output = (((uint32_t)up[0] << 16) |
|
|
((uint32_t)up[1] << 8) | up[2]) >> (8 - OVERSAMPLING);
|
|
|
|
DEBUG("UP: %i\n", (int)*output);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int _compute_b5(const bmp180_t *dev, int32_t ut, int32_t *output)
|
|
{
|
|
int32_t x1 = 0, x2 = 0;
|
|
x1 = (((int32_t)ut - (int32_t)dev->calibration.ac6) * (int32_t)dev->calibration.ac5) >> 15;
|
|
x2 = ((int32_t)dev->calibration.mc << 11) / (x1 + dev->calibration.md);
|
|
|
|
*output = x1 + x2;
|
|
|
|
return 0;
|
|
}
|