1031 lines
28 KiB
C
1031 lines
28 KiB
C
/****************************************************************************
|
|
* drivers/sensors/scd41.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 <stdint.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <fcntl.h>
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <time.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/kmalloc.h>
|
|
#include <nuttx/signal.h>
|
|
#include <nuttx/fs/fs.h>
|
|
#include <nuttx/i2c/i2c_master.h>
|
|
#include <nuttx/sensors/scd41.h>
|
|
#include <nuttx/random.h>
|
|
|
|
#if defined(CONFIG_SENSORS_SCD41)
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SCD41_DEBUG
|
|
# define scd41_dbg(x, ...) _info(x, ##__VA_ARGS__)
|
|
#else
|
|
# define scd41_dbg(x, ...) sninfo(x, ##__VA_ARGS__)
|
|
#endif
|
|
|
|
#ifndef CONFIG_SCD41_I2C_FREQUENCY
|
|
# define CONFIG_SCD41_I2C_FREQUENCY 100000
|
|
#endif
|
|
|
|
#define SCD41_I2C_RETRIES 3
|
|
|
|
/* SCD41 command words */
|
|
|
|
#define SCD41_CMD_START_MEASUREMENT 0x21b1
|
|
#define SCD41_CMD_STOP_MEASUREMENT 0x3f86
|
|
#define SCD41_CMD_GET_DATA_READY 0xe4b8
|
|
#define SCD41_CMD_READ_MEASUREMENT 0xec05
|
|
#define SCD41_CMD_SET_ASC 0x2416
|
|
#define SCD41_CMD_GET_ASC 0x2313
|
|
#define SCD41_CMD_SET_FRC 0x362f
|
|
#define SCD41_CMD_SET_TEMP_OFFSET 0x241d
|
|
#define SCD41_CMD_GET_TEMP_OFFSET 0x2318
|
|
#define SCD41_CMD_SET_ALT_COMPENSATION 0x2427
|
|
#define SCD41_CMD_GET_ALT_COMPENSATION 0x2322
|
|
#define SCD41_CMD_SET_PRESSURE_COMP 0xe000
|
|
#define SCD41_CMD_SOFT_RESET 0x3646
|
|
#define SCD41_CMD_LOWPOWER_MODE 0x21ac
|
|
#define SCD41_CMD_PERSIST_SETTINGS 0x3615
|
|
#define SCD41_CMD_GET_SERIAL_NUMBER 0x3682
|
|
#define SCD41_CMD_START_SELFTEST 0x3639
|
|
#define SCD41_CMD_FACTORY_RESET 0x3632
|
|
#define SCD41_CMD_ONESHOT_MEASUREMENT 0x219d
|
|
#define SCD41_CMD_ONESHOT_MEASURE_RHT 0x2196
|
|
|
|
#define SCD41_DEFAULT_MEASUREMENT_INTERVAL 5 /* seconds */
|
|
#define SCD41_DEFAULT_PRESSURE_COMPENSATION 0
|
|
#define SCD41_DEFAULT_ALTITUDE_COMPENSATION 0
|
|
#define SCD41_DEFAULT_TEMPERATURE_OFFSET 0
|
|
|
|
/****************************************************************************
|
|
* Private
|
|
****************************************************************************/
|
|
|
|
struct scd41_dev_s
|
|
{
|
|
#ifdef CONFIG_SCD41_I2C
|
|
FAR struct i2c_master_s *i2c; /* I2C interface */
|
|
uint8_t addr; /* I2C address */
|
|
#endif
|
|
bool valid; /* If cached readings are valid */
|
|
bool started; /* If continuous measurement is enabled */
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
bool unlinked; /* True, driver has been unlinked */
|
|
#endif
|
|
struct timespec last_update; /* Last time when sensor was read */
|
|
float co2; /* Cached CO₂ (PPM) */
|
|
float temperature; /* Cached temperature (°C) */
|
|
float humidity; /* Cached humidity (RH%) */
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
int16_t crefs; /* Number of open references */
|
|
#endif
|
|
sem_t devsem;
|
|
uint16_t pressure_comp; /* Pressure compensation in mbar (non-zero
|
|
* value overrides altitude compensation). */
|
|
uint16_t altitude_comp; /* Altitude compensation in meters */
|
|
uint16_t interval; /* Background measurement interval in
|
|
* seconds (2 to 1800). */
|
|
uint16_t temperature_offset; /* Temperature offset in 0.01 Kelvin. */
|
|
};
|
|
|
|
struct scd41_word_s
|
|
{
|
|
uint8_t data[2];
|
|
uint8_t crc;
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/* IO Helpers */
|
|
|
|
#ifdef CONFIG_SCD41_I2C
|
|
static int scd41_do_transfer(FAR struct i2c_master_s *i2c,
|
|
FAR struct i2c_msg_s *msgv,
|
|
size_t nmsg);
|
|
#endif
|
|
static int scd41_write_cmd(FAR struct scd41_dev_s *priv, uint16_t cmd,
|
|
FAR struct scd41_word_s *params,
|
|
unsigned int num_params);
|
|
static int scd41_read_words(FAR struct scd41_dev_s *priv,
|
|
FAR struct scd41_word_s *words,
|
|
unsigned int num_words);
|
|
|
|
/* Data conversion */
|
|
|
|
static uint8_t scd41_crc_word(uint16_t word);
|
|
static void scd41_set_command_param(FAR struct scd41_word_s *param,
|
|
uint16_t value);
|
|
static int scd41_check_data_crc(FAR const struct scd41_word_s *words,
|
|
unsigned int num_words);
|
|
static uint16_t scd41_data_word2uint16(FAR const struct scd41_word_s *word);
|
|
|
|
/* Driver features */
|
|
|
|
static int scd41_read_values(FAR struct scd41_dev_s *priv, FAR float *temp,
|
|
FAR float *rh, FAR float *co2, bool wait);
|
|
static int scd41_configure(FAR struct scd41_dev_s *priv, bool start);
|
|
|
|
/* Character driver methods */
|
|
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
static int scd41_open(FAR struct file *filep);
|
|
static int scd41_close(FAR struct file *filep);
|
|
#endif
|
|
static ssize_t scd41_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen);
|
|
static ssize_t scd41_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen);
|
|
static int scd41_ioctl(FAR struct file *filep, int cmd,
|
|
unsigned long arg);
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
static int scd41_unlink(FAR struct inode *inode);
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static const struct file_operations g_scd41fops =
|
|
{
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
scd41_open, /* open */
|
|
scd41_close, /* close */
|
|
#else
|
|
NULL, /* open */
|
|
NULL, /* close */
|
|
#endif
|
|
scd41_read, /* read */
|
|
scd41_write, /* write */
|
|
NULL, /* seek */
|
|
scd41_ioctl, /* ioctl */
|
|
NULL /* poll */
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
, scd41_unlink /* unlink */
|
|
#endif
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_do_transfer
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SCD41_I2C
|
|
static int scd41_do_transfer(FAR struct i2c_master_s *i2c,
|
|
FAR struct i2c_msg_s *msgv,
|
|
size_t nmsg)
|
|
{
|
|
int ret = -EIO;
|
|
int retries;
|
|
|
|
for (retries = 0; retries < SCD41_I2C_RETRIES; retries++)
|
|
{
|
|
ret = I2C_TRANSFER(i2c, msgv, nmsg);
|
|
if (ret >= 0)
|
|
{
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
/* Some error. Try to reset I2C bus and keep trying. */
|
|
|
|
#ifdef CONFIG_I2C_RESET
|
|
if (retries == SCD41_I2C_RETRIES - 1)
|
|
{
|
|
break;
|
|
}
|
|
|
|
ret = I2C_RESET(i2c);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("I2C_RESET failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
scd41_dbg("xfer failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_write_cmd
|
|
****************************************************************************/
|
|
|
|
static int scd41_write_cmd(FAR struct scd41_dev_s *priv, uint16_t cmd,
|
|
FAR struct scd41_word_s *params,
|
|
unsigned int num_params)
|
|
{
|
|
#ifdef CONFIG_SCD41_I2C
|
|
struct i2c_msg_s msg[2];
|
|
uint8_t cmd_buf[2];
|
|
int ret;
|
|
|
|
cmd_buf[0] = cmd >> 8;
|
|
cmd_buf[1] = cmd >> 0;
|
|
|
|
msg[0].frequency = CONFIG_SCD41_I2C_FREQUENCY;
|
|
msg[0].addr = priv->addr;
|
|
msg[0].flags = 0;
|
|
msg[0].buffer = cmd_buf;
|
|
msg[0].length = 2;
|
|
|
|
if (num_params)
|
|
{
|
|
msg[1].frequency = CONFIG_SCD41_I2C_FREQUENCY;
|
|
msg[1].addr = priv->addr;
|
|
msg[1].flags = I2C_M_NOSTART;
|
|
msg[1].buffer = (FAR uint8_t *)params;
|
|
msg[1].length = num_params * sizeof(*params);
|
|
}
|
|
|
|
ret = scd41_do_transfer(priv->i2c, msg, (num_params) ? 2 : 1);
|
|
|
|
scd41_dbg("cmd: 0x%04X num_params: %d ret: %d\n",
|
|
cmd, num_params, ret);
|
|
return (ret >= 0) ? OK : ret;
|
|
#else
|
|
/* UART mode not implemented yet. */
|
|
|
|
return -ENODEV;
|
|
#endif
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_read_words
|
|
****************************************************************************/
|
|
|
|
static int scd41_read_words(FAR struct scd41_dev_s *priv,
|
|
FAR struct scd41_word_s *words,
|
|
unsigned int num_words)
|
|
{
|
|
#ifdef CONFIG_SCD41_I2C
|
|
struct i2c_msg_s msg[1];
|
|
int ret;
|
|
|
|
msg[0].frequency = CONFIG_SCD41_I2C_FREQUENCY;
|
|
msg[0].addr = priv->addr;
|
|
msg[0].flags = I2C_M_READ;
|
|
msg[0].buffer = (FAR uint8_t *)words;
|
|
msg[0].length = num_words * sizeof(*words);
|
|
|
|
ret = scd41_do_transfer(priv->i2c, msg, 1);
|
|
|
|
scd41_dbg("num_words: %d ret: %d\n", num_words, ret);
|
|
return (ret >= 0) ? OK : ret;
|
|
#else
|
|
/* UART mode not implemented yet. */
|
|
|
|
return -ENODEV;
|
|
#endif
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_crc_word
|
|
****************************************************************************/
|
|
|
|
static uint8_t scd41_crc_word(uint16_t word)
|
|
{
|
|
static const uint8_t crc_table[16] =
|
|
{
|
|
0x00, 0x31, 0x62, 0x53, 0xc4, 0xf5, 0xa6, 0x97,
|
|
0xb9, 0x88, 0xdb, 0xea, 0x7d, 0x4c, 0x1f, 0x2e
|
|
};
|
|
|
|
uint8_t crc = 0xff;
|
|
|
|
crc ^= word >> 8;
|
|
crc = (crc << 4) ^ crc_table[crc >> 4];
|
|
crc = (crc << 4) ^ crc_table[crc >> 4];
|
|
crc ^= word >> 0;
|
|
crc = (crc << 4) ^ crc_table[crc >> 4];
|
|
crc = (crc << 4) ^ crc_table[crc >> 4];
|
|
|
|
return crc;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_set_command_param
|
|
****************************************************************************/
|
|
|
|
static void scd41_set_command_param(FAR struct scd41_word_s *param,
|
|
uint16_t value)
|
|
{
|
|
param->data[0] = value >> 8;
|
|
param->data[1] = value >> 0;
|
|
param->crc = scd41_crc_word(value);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_data_word2uint16
|
|
****************************************************************************/
|
|
|
|
static uint16_t scd41_data_word2uint16(FAR const struct scd41_word_s *word)
|
|
{
|
|
return (word[0].data[0] << 8) | (word[0].data[1]);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_crc_word
|
|
****************************************************************************/
|
|
|
|
static int scd41_check_data_crc(FAR const struct scd41_word_s *words,
|
|
unsigned int num_words)
|
|
{
|
|
while (num_words)
|
|
{
|
|
if (scd41_crc_word(scd41_data_word2uint16(words)) != words->crc)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
num_words--;
|
|
words++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_softreset
|
|
*
|
|
* Description:
|
|
* Reset the SCD41 sensor. This takes less than 2000 ms.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int scd41_softreset(FAR struct scd41_dev_s *priv)
|
|
{
|
|
int ret;
|
|
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_SOFT_RESET, NULL, 0);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: has_time_passed
|
|
*
|
|
* Description:
|
|
* Return true if curr >= start + secs_since_start
|
|
*
|
|
****************************************************************************/
|
|
|
|
static bool has_time_passed(struct timespec curr,
|
|
struct timespec start,
|
|
unsigned int secs_since_start)
|
|
{
|
|
if ((long)((start.tv_sec + secs_since_start) - curr.tv_sec) == 0)
|
|
{
|
|
return start.tv_nsec <= curr.tv_nsec;
|
|
}
|
|
|
|
return (long)((start.tv_sec + secs_since_start) - curr.tv_sec) <= 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_read_values
|
|
****************************************************************************/
|
|
|
|
static int scd41_read_values(FAR struct scd41_dev_s *priv, FAR float *temp,
|
|
FAR float *rh, FAR float *co2, bool wait)
|
|
{
|
|
struct scd41_word_s data[3];
|
|
struct timespec ts;
|
|
int ret;
|
|
|
|
clock_systime_timespec(&ts);
|
|
|
|
if (wait || !priv->valid ||
|
|
has_time_passed(ts, priv->last_update,
|
|
SCD41_DEFAULT_MEASUREMENT_INTERVAL))
|
|
{
|
|
while (1)
|
|
{
|
|
/* Wait data to be ready. */
|
|
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_GET_DATA_READY, NULL, 0);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("ERROR: scd41_write_cmd failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = scd41_read_words(priv, data, 1);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("ERROR: scd41_read_words failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
if (scd41_check_data_crc(data, 1) < 0)
|
|
{
|
|
scd41_dbg("ERROR: scd41_read_words crc failed\n");
|
|
ret = -EIO;
|
|
return ret;
|
|
}
|
|
|
|
if ((scd41_data_word2uint16(data) & 0x07ff) == 0x0000)
|
|
{
|
|
if (!wait)
|
|
{
|
|
scd41_dbg("ERROR: data not ready\n");
|
|
ret = -EAGAIN;
|
|
return ret;
|
|
}
|
|
|
|
ret = nxsig_usleep(500 * 1000);
|
|
if (ret == -EINTR)
|
|
{
|
|
return ret;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Read the raw data */
|
|
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_READ_MEASUREMENT, NULL, 0);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("ERROR: scd41_write_cmd failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = scd41_read_words(priv, data, 3);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("ERROR: scd41_read_words failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
if (scd41_check_data_crc(data, 3) < 0)
|
|
{
|
|
scd41_dbg("ERROR: scd41_read_words crc failed\n");
|
|
ret = -EIO;
|
|
return ret;
|
|
}
|
|
|
|
add_sensor_randomness((data[0].crc << 16) ^ (data[1].crc << 8) ^
|
|
data[2].crc);
|
|
|
|
priv->co2 = (float)scd41_data_word2uint16(data + 0);
|
|
uint16_t tval = scd41_data_word2uint16(data + 1);
|
|
priv->temperature = (float)((tval * 175.0) / 65536.0 - 45.0);
|
|
uint16_t hval = scd41_data_word2uint16(data + 2);
|
|
priv->humidity = (float)(hval * 100.0 / 65536.0);
|
|
priv->last_update = ts;
|
|
priv->valid = true;
|
|
}
|
|
|
|
*temp = priv->temperature;
|
|
*rh = priv->humidity;
|
|
*co2 = priv->co2;
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_configure
|
|
****************************************************************************/
|
|
|
|
static int scd41_configure(FAR struct scd41_dev_s *priv, bool start)
|
|
{
|
|
struct scd41_word_s param;
|
|
int ret = OK;
|
|
|
|
/* Set altitude compensation. */
|
|
|
|
scd41_set_command_param(¶m, priv->altitude_comp);
|
|
scd41_write_cmd(priv, SCD41_CMD_SET_ALT_COMPENSATION, ¶m, 1);
|
|
|
|
/* Set temperature offset. */
|
|
|
|
scd41_set_command_param(¶m, priv->temperature_offset);
|
|
scd41_write_cmd(priv, SCD41_CMD_SET_TEMP_OFFSET, ¶m, 1);
|
|
|
|
/* Set pressure compensation. */
|
|
|
|
scd41_set_command_param(¶m, priv->pressure_comp);
|
|
scd41_write_cmd(priv, SCD41_CMD_SET_PRESSURE_COMP, ¶m, 1);
|
|
|
|
if (start)
|
|
{
|
|
/* Start measurements. */
|
|
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_START_MEASUREMENT, NULL, 0);
|
|
if (ret >= 0)
|
|
{
|
|
priv->started = true;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_open
|
|
*
|
|
* Description:
|
|
* This function is called whenever the SCD41x device is opened.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
static int scd41_open(FAR struct file *filep)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct scd41_dev_s *priv = inode->i_private;
|
|
int ret = OK;
|
|
|
|
/* Get exclusive access */
|
|
|
|
ret = nxsem_wait_uninterruptible(&priv->devsem);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
/* Increment the count of open references on the driver */
|
|
|
|
priv->crefs++;
|
|
DEBUGASSERT(priv->crefs > 0);
|
|
|
|
if (priv->crefs == 1)
|
|
{
|
|
ret = scd41_configure(priv, true);
|
|
}
|
|
|
|
if (ret < 0)
|
|
{
|
|
priv->crefs--;
|
|
}
|
|
|
|
nxsem_post(&priv->devsem);
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_close
|
|
*
|
|
* Description:
|
|
* This routine is called when the SCD41 device is closed.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
static int scd41_close(FAR struct file *filep)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct scd41_dev_s *priv = inode->i_private;
|
|
int ret;
|
|
|
|
/* Get exclusive access */
|
|
|
|
ret = nxsem_wait_uninterruptible(&priv->devsem);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
/* Decrement the count of open references on the driver */
|
|
|
|
DEBUGASSERT(priv->crefs > 0);
|
|
priv->crefs--;
|
|
|
|
/* If the count has decremented to zero and the driver has been unlinked,
|
|
* then free memory now.
|
|
*/
|
|
|
|
if (priv->crefs <= 0 && priv->unlinked)
|
|
{
|
|
nxsem_destroy(&priv->devsem);
|
|
kmm_free(priv);
|
|
return OK;
|
|
}
|
|
|
|
nxsem_post(&priv->devsem);
|
|
return OK;
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_read
|
|
****************************************************************************/
|
|
|
|
static ssize_t scd41_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct scd41_dev_s *priv = inode->i_private;
|
|
ssize_t length = 0;
|
|
float temp;
|
|
float rh;
|
|
float co2;
|
|
unsigned int temp100;
|
|
unsigned int rh100;
|
|
unsigned int co2_100;
|
|
int ret;
|
|
|
|
/* Get exclusive access */
|
|
|
|
ret = nxsem_wait_uninterruptible(&priv->devsem);
|
|
if (ret < 0)
|
|
{
|
|
return (ssize_t)ret;
|
|
}
|
|
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
if (priv->unlinked)
|
|
{
|
|
/* Do not allow operations on unlinked sensors. This allows
|
|
* sensor use on hot swappable I2C bus.
|
|
*/
|
|
|
|
nxsem_post(&priv->devsem);
|
|
return -ENODEV;
|
|
}
|
|
#endif
|
|
|
|
if (!priv->started)
|
|
{
|
|
return -ENODATA;
|
|
}
|
|
|
|
ret = scd41_read_values(priv, &temp, &rh, &co2,
|
|
!(filep->f_oflags & O_NONBLOCK));
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("cannot read data: %d\n", ret);
|
|
}
|
|
else
|
|
{
|
|
/* This interface is mainly intended for easy debugging in nsh. */
|
|
|
|
temp100 = abs(temp * 100);
|
|
rh100 = abs(rh * 100);
|
|
co2_100 = abs(co2 * 100);
|
|
|
|
length = snprintf(buffer, buflen, "%s%u.%02u %s%u.%02u %s%u.%02u\n",
|
|
co2 < 0 ? "-" : "", co2_100 / 100, co2_100 % 100,
|
|
temp < 0 ? "-" : "", temp100 / 100, temp100 % 100,
|
|
rh < 0 ? "-" : "", rh100 / 100, rh100 % 100);
|
|
if (length > buflen)
|
|
{
|
|
length = buflen;
|
|
}
|
|
}
|
|
|
|
nxsem_post(&priv->devsem);
|
|
return length;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_write
|
|
****************************************************************************/
|
|
|
|
static ssize_t scd41_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_ioctl
|
|
****************************************************************************/
|
|
|
|
static int scd41_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct scd41_dev_s *priv = inode->i_private;
|
|
struct scd41_word_s param;
|
|
int ret;
|
|
|
|
/* Get exclusive access */
|
|
|
|
ret = nxsem_wait_uninterruptible(&priv->devsem);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
if (priv->unlinked)
|
|
{
|
|
/* Do not allow operations on unlinked sensors. This allows
|
|
* sensor use on hot swappable I2C bus.
|
|
*/
|
|
|
|
nxsem_post(&priv->devsem);
|
|
return -ENODEV;
|
|
}
|
|
#endif
|
|
|
|
switch (cmd)
|
|
{
|
|
/* Soft reset the SCD41, Arg: None */
|
|
|
|
case SNIOC_RESET:
|
|
{
|
|
priv->interval = SCD41_DEFAULT_MEASUREMENT_INTERVAL;
|
|
priv->pressure_comp = SCD41_DEFAULT_PRESSURE_COMPENSATION;
|
|
priv->altitude_comp = SCD41_DEFAULT_ALTITUDE_COMPENSATION;
|
|
priv->temperature_offset = SCD41_DEFAULT_TEMPERATURE_OFFSET;
|
|
|
|
ret = scd41_softreset(priv);
|
|
scd41_dbg("softreset ret: %d\n", ret);
|
|
|
|
scd41_configure(priv, priv->started);
|
|
}
|
|
break;
|
|
|
|
/* Start background measurement, Arg: None */
|
|
|
|
case SNIOC_START:
|
|
{
|
|
/* Start measurements. */
|
|
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_START_MEASUREMENT, NULL, 0);
|
|
if (ret >= 0)
|
|
{
|
|
priv->started = true;
|
|
}
|
|
}
|
|
break;
|
|
|
|
/* Stop background measurement, Arg: None */
|
|
|
|
case SNIOC_STOP:
|
|
{
|
|
/* Stop measurements. */
|
|
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_STOP_MEASUREMENT, NULL, 0);
|
|
if (ret >= 0)
|
|
{
|
|
priv->started = false;
|
|
}
|
|
}
|
|
break;
|
|
|
|
/* Set temperature offset value, Arg: uint16_t */
|
|
|
|
case SNIOC_SET_TEMP_OFFSET:
|
|
{
|
|
if (arg > UINT16_MAX)
|
|
{
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
/* Actual Toffset = temperature_offset * 175.0 / 2^16 */
|
|
|
|
priv->temperature_offset = arg;
|
|
scd41_set_command_param(¶m, priv->temperature_offset);
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_SET_TEMP_OFFSET, ¶m, 1);
|
|
}
|
|
break;
|
|
|
|
/* Set pressure compensation value, Arg: uint16_t */
|
|
|
|
case SNIOC_SET_PRESSURE_COMP:
|
|
{
|
|
if (arg > UINT16_MAX)
|
|
{
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
priv->pressure_comp = arg;
|
|
scd41_set_command_param(¶m, priv->pressure_comp);
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_SET_PRESSURE_COMP,
|
|
¶m, 1);
|
|
}
|
|
break;
|
|
|
|
/* Set altitude compensation value, Arg: uint16_t */
|
|
|
|
case SNIOC_SET_ALTITUDE_COMP:
|
|
{
|
|
if (arg > UINT16_MAX)
|
|
{
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
priv->altitude_comp = arg;
|
|
scd41_set_command_param(¶m, priv->altitude_comp);
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_SET_ALT_COMPENSATION,
|
|
¶m, 1);
|
|
}
|
|
break;
|
|
|
|
/* Set Forced Recalibration value (FRC), Arg: uint16_t */
|
|
|
|
case SNIOC_SET_FRC:
|
|
{
|
|
if (arg > UINT16_MAX)
|
|
{
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
scd41_set_command_param(¶m, arg);
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_SET_FRC, ¶m, 1);
|
|
}
|
|
break;
|
|
|
|
/* (De-)Activate Automatic Self-Calibration (ASC), Arg: bool */
|
|
|
|
case SNIOC_ENABLE_ASC:
|
|
{
|
|
if (arg != !!arg) /* 0 or 1 */
|
|
{
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
scd41_set_command_param(¶m, arg);
|
|
ret = scd41_write_cmd(priv, SCD41_CMD_SET_ASC, ¶m, 1);
|
|
}
|
|
break;
|
|
|
|
/* Read sensor data, Arg: struct scd41_conv_data_s *data */
|
|
|
|
case SNIOC_READ_CONVERT_DATA:
|
|
{
|
|
float temp;
|
|
float rh;
|
|
float co2;
|
|
|
|
ret = scd41_read_values(priv, &temp, &rh, &co2, false);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("cannot read data: %d\n", ret);
|
|
}
|
|
else
|
|
{
|
|
FAR struct scd41_conv_data_s *data =
|
|
(FAR struct scd41_conv_data_s *)arg;
|
|
|
|
data->temperature = temp;
|
|
data->humidity = rh;
|
|
data->co2 = co2;
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
scd41_dbg("Unrecognized cmd: %d\n", cmd);
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
nxsem_post(&priv->devsem);
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: scd41_unlink
|
|
****************************************************************************/
|
|
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
static int scd41_unlink(FAR struct inode *inode)
|
|
{
|
|
FAR struct scd41_dev_s *priv;
|
|
int ret;
|
|
|
|
DEBUGASSERT(inode != NULL && inode->i_private != NULL);
|
|
priv = (FAR struct scd41_dev_s *)inode->i_private;
|
|
|
|
/* Get exclusive access */
|
|
|
|
ret = nxsem_wait_uninterruptible(&priv->devsem);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
/* Are there open references to the driver data structure? */
|
|
|
|
if (priv->crefs <= 0)
|
|
{
|
|
nxsem_destroy(&priv->devsem);
|
|
kmm_free(priv);
|
|
return OK;
|
|
}
|
|
|
|
/* No... just mark the driver as unlinked and free the resources when
|
|
* the last client closes their reference to the driver.
|
|
*/
|
|
|
|
priv->unlinked = true;
|
|
nxsem_post(&priv->devsem);
|
|
return OK;
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SCD41_I2C
|
|
/****************************************************************************
|
|
* Name: scd41_register_i2c
|
|
*
|
|
* Description:
|
|
* Register the SCD41 character device as 'devpath'
|
|
*
|
|
* Input Parameters:
|
|
* devpath - The full path to the driver to register. E.g., "/dev/co2_0"
|
|
* i2c - An instance of the I2C interface to use to communicate with
|
|
* the SCD41
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success; a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int scd41_register_i2c(FAR const char *devpath, FAR struct i2c_master_s *i2c)
|
|
{
|
|
FAR struct scd41_dev_s *priv;
|
|
int ret;
|
|
|
|
DEBUGASSERT(i2c != NULL);
|
|
DEBUGASSERT(scd41_crc_word(0xbeef) == 0x92);
|
|
|
|
/* Initialize the device structure */
|
|
|
|
priv = (FAR struct scd41_dev_s *)kmm_zalloc(sizeof(struct scd41_dev_s));
|
|
if (priv == NULL)
|
|
{
|
|
scd41_dbg("ERROR: Failed to allocate instance\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
priv->i2c = i2c;
|
|
priv->addr = CONFIG_SCD41_ADDR;
|
|
priv->started = false;
|
|
priv->interval = SCD41_DEFAULT_MEASUREMENT_INTERVAL;
|
|
priv->pressure_comp = SCD41_DEFAULT_PRESSURE_COMPENSATION;
|
|
priv->altitude_comp = SCD41_DEFAULT_ALTITUDE_COMPENSATION;
|
|
priv->temperature_offset = SCD41_DEFAULT_TEMPERATURE_OFFSET;
|
|
|
|
nxsem_init(&priv->devsem, 0, 1);
|
|
|
|
/* Register the character driver */
|
|
|
|
ret = register_driver(devpath, &g_scd41fops, 0666, priv);
|
|
if (ret < 0)
|
|
{
|
|
scd41_dbg("ERROR: Failed to register driver: %d\n", ret);
|
|
kmm_free(priv);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_SCD41_I2C */
|
|
|
|
#endif /* CONFIG_SENSORS_SCD41 */
|