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drivers/sensors: Adds new driver for ds18b20 sensore module

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Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
This commit is contained in:
Marco Krahl 2021-04-10 14:01:10 +02:00 committed by Xiang Xiao
parent 624a60f456
commit 9f9d266f68
5 changed files with 1133 additions and 5 deletions
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29
drivers/sensors/Kconfig
View File

@ -171,6 +171,35 @@ config SENSORS_DHTXX
---help---
Enable driver support for the DHTxx humidity/temperature sensor.
config SENSORS_DS18B20
bool "Maxim Integrated DS18B20 Temperature Sensor support"
default n
select 1WIRE
---help---
Enable driver support for the DS18B20 temperature sensor.
config SENSORS_DS18B20_POLL
bool "Enables polling sensor data"
depends on SENSORS_DS18B20
default n
---help---
Enables polling of sensor.
config SENSORS_DS18B20_POLL_INTERVAL
int "Polling interval in microseconds, default 1 sec"
depends on SENSORS_DS18B20 && SENSORS_DS18B20_POLL
default 1000000
range 0 4294967295
---help---
The interval until a new sensor measurement will be triggered.
config SENSORS_DS18B20_THREAD_STACKSIZE
int "Worker thread stack size"
depends on SENSORS_DS18B20 && SENSORS_DS18B20_POLL
default 1024
---help---
The stack size for the worker thread.
config SENSORS_FXOS8700CQ
bool "NXP FXOS8700CQ Motion Sensor support"
default n

10
drivers/sensors/Make.defs
View File

@ -260,6 +260,16 @@ endif
endif # CONFIG_SPI
# These drivers depend on 1WIRE support
ifeq ($(CONFIG_1WIRE),y)
ifeq ($(CONFIG_SENSORS_DS18B20),y)
CSRCS += ds18b20.c
endif
endif # CONFIG_1WIRE
ifeq ($(CONFIG_SENSORS_MPU60X0),y)
CSRCS += mpu60x0.c
endif

987
drivers/sensors/ds18b20.c Normal file
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@ -0,0 +1,987 @@
/****************************************************************************
* drivers/sensors/ds18b20.c
* Character driver for DS18B20 Digital Humidity and Temperature Module.
*
* 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 <errno.h>
#include <debug.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <nuttx/kmalloc.h>
#include <nuttx/kthread.h>
#include <nuttx/signal.h>
#include <nuttx/semaphore.h>
#include <nuttx/fs/fs.h>
#include <nuttx/1wire/1wire.h>
#include <nuttx/1wire/1wire_master.h>
#include <nuttx/1wire/1wire_crc.h>
#include <nuttx/sensors/ds18b20.h>
#include <nuttx/sensors/sensor.h>
#if defined(CONFIG_1WIRE) && defined(CONFIG_SENSORS_DS18B20)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_ENDIAN_BIG
# define ds18b20_leuint64(x) (x)
#endif
/* Scratchpad data definition for reading */
#define DS18B20_SPAD_LSB_OFFSET 0
#define DS18B20_SPAD_MSB_OFFSET 1
#define DS18B20_SPAD_TH_OFFSET 2
#define DS18B20_SPAD_TL_OFFSET 3
#define DS18B20_SPAD_RES_OFFSET 4
#define DS18B20_SPAD_CRC_OFFSET 9
#define DS18B20_SPAD_SIZE 9
/* Scratchpad data definition for writing */
#define DS18B20_WSPAD_CMD_OFFSET 0
#define DS18B20_WSPAD_TH_OFFSET 0
#define DS18B20_WSPAD_TL_OFFSET 1
#define DS18B20_WSPAD_RES_OFFSET 2
#define DS18B20_WSPAD_SIZE 3
/* Measurement resolution bit definition */
#define DS18B20_RESMIN 0
#define DS18B20_RESMAX 3
#define DS18B20_NRES DS18B20_RESMAX - DS18B20_RESMIN + 1
#define DS18B20_RES_VAL(x) (((x) >> 5) & 0x3)
#define DS18B20_RES_CONV(x) (((x) & 0x3) << 5)
/* Measurement timneout offset */
#define DS18B20_TIMEOUT_OFFSET(x) (DS18B20_RESMAX - (x))
/* Default alarm temperature */
#define DS18B20_TALARM_MIN -55
#define DS18B20_TALARM_MAX 125
/* Helper for getting data from scratchpad memory */
#define DS18B20_TEMP_PREDEC(lsb, msb) (int8_t)(((msb) << 4) | ((lsb) >> 4))
#define DS18B20_TEMP_RES(lsb, res) (DS18B20_RESMAX - DS18B20_RES_VAL(res))
#define DS18B20_TEMP_RESMASK(lsb, res) (0x0f << DS18B20_TEMP_RES(lsb, res))
#define DS18B20_TEMP_DEC(lsb, res) (((lsb) & 0x0f) & \
DS18B20_TEMP_RESMASK(lsb, res))
#define DS18B20_TEMP(lsb, msb, res) (DS18B20_TEMP_PREDEC(lsb, msb) + \
DS18B20_TEMP_DEC(lsb, res) / 16.0)
/****************************************************************************
* Private Types
****************************************************************************/
/* Internal sensor data */
struct ds18b20_sensor_data_s
{
uint64_t timestamp;
uint8_t spad[DS18B20_SPAD_SIZE];
};
/* User configuration register */
struct ds18b20_config_s
{
uint8_t res; /* Sensor resolution */
struct ds18b20_alarm_s alarm; /* Sensor temperature alarm */
};
/* Callback handling for alarm detection */
struct ds18b20_cb_alarm_s
{
bool isalarm;
uint64_t romcode;
};
/* Lower sensor */
struct ds18b20_sensor_s
{
struct sensor_lowerhalf_s lower; /* Common lower interface */
#ifdef CONFIG_SENSORS_DS18B20_POLL
bool enabled; /* Sensor activated */
#endif
};
/* Internal device */
struct ds18b20_dev_s
{
struct ds18b20_sensor_s sensor; /* Sensor */
FAR struct onewire_master_s *master; /* 1wire master interface */
struct onewire_config_s config; /* 1wire device configuration */
struct ds18b20_config_s reg; /* Sensor resolution */
#ifdef CONFIG_SENSORS_DS18B20_POLL
unsigned int interval; /* Polling interval */
sem_t run; /* Locks sensor thread */
#endif
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Sensor functions */
static int ds18b20_active(FAR struct sensor_lowerhalf_s *lower,
unsigned char enabled);
static int ds18b20_fetch(FAR struct sensor_lowerhalf_s *lower,
FAR char *buffer, size_t buflen);
static int ds18b20_control(FAR struct sensor_lowerhalf_s *lower,
int cmd, unsigned long arg);
#ifdef CONFIG_SENSORS_DS18B20_POLL
static int ds18b20_set_interval(FAR struct sensor_lowerhalf_s *lower,
FAR unsigned int *period_us);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/* Timeout definitions after measurement according to the data sheet */
static const uint32_t g_res_timeout[DS18B20_NRES] =
{
93750,
187500,
375000,
750000
};
static const struct sensor_ops_s g_ds18b20_ops =
{
#ifdef CONFIG_SENSORS_DS18B20_POLL
.set_interval = ds18b20_set_interval,
#endif
.activate = ds18b20_active,
.fetch = ds18b20_fetch,
.control = ds18b20_control
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: ds18b20_rawdata
*
* Description:
* Helper for extract temperature data from scratchpad
*
* Return:
* Raw temperature data
*
****************************************************************************/
static inline int16_t ds18b20_rawtemp(FAR const uint8_t *spad)
{
return (spad[DS18B20_SPAD_LSB_OFFSET] |
(spad[DS18B20_SPAD_MSB_OFFSET] << 8));
}
/****************************************************************************
* Name: ds18b20_tempdata
*
* Description:
* Helper for converting temperatur data from raw sensor data
*
* Return:
* Temperature data
*
****************************************************************************/
static inline float ds18b20_temp(FAR const uint8_t *spad)
{
int8_t predec = DS18B20_TEMP_PREDEC(spad[DS18B20_SPAD_LSB_OFFSET],
spad[DS18B20_SPAD_MSB_OFFSET]);
uint8_t dec = DS18B20_TEMP_DEC(spad[DS18B20_SPAD_LSB_OFFSET],
spad[DS18B20_SPAD_RES_OFFSET]);
return predec + dec / 16.0;
}
/****************************************************************************
* Name: ds18b20_alarm_cb
*
* Description:
* Call back function for searching a single alarm device.
*
* Input Parameters:
* romcode - Unique romcode of a device with alarm flag set
* arg - Pointer to struct onewire_alarm_s
*
****************************************************************************/
#ifdef CONFIG_SENSORS_DS18B20_POLL
static void ds18b20_alarm_cb(int family, uint64_t romcode, FAR void *arg)
{
FAR struct ds18b20_cb_alarm_s *priv = (FAR struct ds18b20_cb_alarm_s *)arg;
if (romcode == priv->romcode)
{
priv->isalarm = true;
}
}
#endif
/****************************************************************************
* Name: ds18b20_isalarm
*
* Description:
* Check if a 1wire device has set the alarm flag in an atomic operation.
*
* Input Parameters:
* master - Pointer to the allocated 1-wire interface
* config - Described the 1WIRE configuration
*
* Return Value:
* 0 - no alarm flag is set
* 1 - alarm flag is set
* < 0 - in case of error
*
****************************************************************************/
#ifdef CONFIG_SENSORS_DS18B20_POLL
static int ds18b20_isalarm(FAR struct onewire_master_s *master,
FAR const struct onewire_config_s *config)
{
int ret;
struct ds18b20_cb_alarm_s alarm;
alarm.romcode = config->romcode;
alarm.isalarm = false;
ret = onewire_search(master, config->family, true, ds18b20_alarm_cb,
&alarm);
if (ret > 0)
{
/* Check if our device is in the alarm list */
if (alarm.isalarm == true)
{
ret = 1;
}
else
{
/* Device found, but not our */
ret = 0;
}
}
return ret;
}
#endif
/****************************************************************************
* Name: ds18b20_measure
*
* Description: Perform a measurement
*
* Parameter:
* dev - Internal private lower half driver instance
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_measure(FAR struct ds18b20_dev_s *dev)
{
int ret;
uint8_t buf = DS18B20_CMD_CONVERTT;
ret = onewire_write(dev->master, &dev->config, &buf, 1);
if (ret < 0)
{
snerr("ERROR: Unable to perform a temperature measurement\n");
return ret;
}
return OK;
}
/****************************************************************************
* Name: ds18b20_write_spad
*
* Description: Write scratchpad data to chip
*
* Parameter:
* dev - Internal private lower half driver instance
* th - High alarm temperature
* lh - Low alarm temperature
* res - Temperature resolution
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_write_spad(FAR struct ds18b20_dev_s *dev, int8_t th,
int8_t tl, uint8_t res)
{
int ret;
uint8_t wbuf[DS18B20_WSPAD_SIZE + 1];
wbuf[DS18B20_WSPAD_CMD_OFFSET] = ONEWIRE_CMD_WRITE_SCRATCHPAD;
wbuf[DS18B20_WSPAD_TH_OFFSET + 1] = th;
wbuf[DS18B20_WSPAD_TL_OFFSET + 1] = tl;
wbuf[DS18B20_WSPAD_RES_OFFSET + 1] = res;
ret = onewire_write(dev->master, &dev->config, wbuf, sizeof(wbuf));
if (ret < 0)
{
snerr("ERROR: Unable to write scratchpad\n");
}
return ret;
}
/****************************************************************************
* Name: ds18b20_read_spad
*
* Description: Read scratchpad data from chip
*
* Parameter:
* dev - Internal private lower half driver instance
* spad - Pointer to store the scratchpad data
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_read_spad(FAR struct ds18b20_dev_s *dev,
FAR uint8_t *spad)
{
int ret;
uint8_t crc;
uint8_t wbuf = ONEWIRE_CMD_READ_SCRATCHPAD;
FAR struct ds18b20_config_s *reg = &dev->reg;
ret = onewire_writeread(dev->master, &dev->config, &wbuf, 1, spad,
DS18B20_SPAD_SIZE);
if (ret < 0)
{
snerr("ERROR: Unable to read scratchpad\n");
return ret;
}
crc = onewire_crc8(spad, DS18B20_SPAD_SIZE - 1);
if (crc != spad[DS18B20_SPAD_CRC_OFFSET - 1])
{
snerr("ERROR: crc mismatch in scratchpad\n");
return -EIO;
}
/* Update configurable register state each time reading the scratchpad */
reg->res = spad[DS18B20_SPAD_RES_OFFSET];
if (reg->res < DS18B20_RES_CONV(DS18B20_RESMIN) ||
reg->res > DS18B20_RES_CONV(reg->res))
{
/* Usually this should not happen, but be sure that we did not run into
* a buffer overflow later.
*/
swarn("WARNING: Sensor responsed unknown resolution: %d\n", reg->res);
reg->res = DS18B20_RES_CONV(DS18B20_RESMAX);
}
reg->alarm.thigh = spad[DS18B20_SPAD_TH_OFFSET];
reg->alarm.tlow = spad[DS18B20_SPAD_TL_OFFSET];
return OK;
}
/****************************************************************************
* Name: ds18b20_set_res
*
* Description: Set resolution for temperature measurement
*
* Parameter:
* dev - Internal private lower half driver instance
* res - Resolution, can be 9 to 12 bit
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_set_res(FAR struct ds18b20_dev_s *dev, uint8_t res)
{
int ret;
uint8_t spad[DS18B20_SPAD_SIZE];
/* Read current scratchpad first */
ret = ds18b20_read_spad(dev, spad);
if (ret < 0)
{
return ret;
}
ret = ds18b20_write_spad(dev, dev->reg.alarm.thigh, dev->reg.alarm.tlow,
res);
if (ret < 0)
{
return ret;
}
/* Read current scratchpad again and verify that res is set */
ret = ds18b20_read_spad(dev, spad);
if (ret < 0)
{
return ret;
}
if (DS18B20_RES_VAL(spad[DS18B20_SPAD_RES_OFFSET]) != DS18B20_RES_VAL(res))
{
snerr("ERROR: Expected resolution not matched, received RES: %d\n",
spad[DS18B20_SPAD_RES_OFFSET]);
return -EIO;
}
return OK;
}
/****************************************************************************
* Name: ds18b20_set_alarm
*
* Description: Set temperature alarm
*
* Parameter:
* dev - Internal private lower half driver instance
* alarm - Pointer to store the alarm temperature
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_set_alarm(FAR struct ds18b20_dev_s *dev,
FAR const struct ds18b20_alarm_s *alarm)
{
int ret;
uint8_t spad[DS18B20_SPAD_SIZE];
/* Read current scratchpad first, to get current resolution */
ret = ds18b20_read_spad(dev, spad);
if (ret < 0)
{
return ret;
}
ret = ds18b20_write_spad(dev, alarm->thigh, alarm->tlow, dev->reg.res);
if (ret < 0)
{
return ret;
}
#ifdef CONFIG_SENSORS_DS18B20_POLL
dev->reg.alarm.wakeup = alarm->wakeup;
#endif
/* Read current scratchpad again and verify that alarm is set */
ret = ds18b20_read_spad(dev, spad);
if (ret < 0)
{
return ret;
}
if (spad[DS18B20_SPAD_TH_OFFSET] != alarm->thigh ||
spad[DS18B20_SPAD_TL_OFFSET] != alarm->tlow)
{
snerr("ERROR: Expected alarm trigger does not match, " \
"received TH: %d, TL: %d\n",
spad[DS18B20_SPAD_TH_OFFSET],
spad[DS18B20_SPAD_TL_OFFSET]);
return -EIO;
}
return ret;
}
/****************************************************************************
* Name: ds18b20_curtime
*
* Description: Helper to get current timestamp.
*
* Return:
* Timestamp in nsec
****************************************************************************/
static unsigned long ds18b20_curtime(void)
{
struct timespec ts;
#ifdef CONFIG_CLOCK_MONOTONIC
clock_gettime(CLOCK_MONOTONIC, &ts);
#else
clock_gettime(CLOCK_REALTIME, &ts);
#endif
return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
}
/****************************************************************************
* Name: ds18b20_notify
*
* Description:
* Notify upper about data has been changed.
*
* Parameter:
* dev - Internal private lower half driver instance
* data - Read sensor data
*
****************************************************************************/
#ifdef CONFIG_SENSORS_DS18B20_POLL
static void ds18b20_notify(FAR struct ds18b20_dev_s *dev,
FAR struct ds18b20_sensor_data_s *data)
{
FAR struct ds18b20_sensor_s *sensor = &dev->sensor;
struct sensor_event_temp temp;
temp.temperature = ds18b20_temp(data->spad);
temp.timestamp = data->timestamp;
sensor->lower.push_event(sensor->lower.priv, &temp,
sizeof(struct sensor_event_temp));
}
#endif
/****************************************************************************
* Name: ds18b20_measure_read
*
* Description: Perform a measurement and read last measured temperature
*
* Parameter:
* dev - Internal private lower half driver instance
* data - Pointer to store sensor data
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_measure_read(FAR struct ds18b20_dev_s *dev,
FAR struct ds18b20_sensor_data_s *data)
{
int ret;
ret = ds18b20_measure(dev);
if (ret < 0)
{
return ret;
}
nxsig_usleep(g_res_timeout[DS18B20_RES_VAL(dev->reg.res)]);
ret = ds18b20_read_spad(dev, data->spad);
if (ret < 0)
{
return ret;
}
data->timestamp = ds18b20_curtime();
return OK;
}
/****************************************************************************
* Name: ds18b20_fetch
*
* Description: Performs a measuremnt cylce and data read with data
* conversion.
*
* Parameter:
* lower - Pointer to lower half sensor driver instance
* buffer - Pointer to the buffer for reading data
* buflen - Size of the buffer
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_fetch(FAR struct sensor_lowerhalf_s *lower,
FAR char *buffer, size_t buflen)
{
int ret;
struct ds18b20_sensor_data_s data;
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
/* Check if the user is reading the right size */
if (buflen != sizeof(struct sensor_event_temp))
{
snerr("ERROR: You need to read %d bytes from this sensor!\n",
sizeof(struct sensor_event_temp));
return -EINVAL;
}
ret = ds18b20_measure_read(priv, &data);
if (!ret)
{
FAR struct sensor_event_temp *temp =
(FAR struct sensor_event_temp *)buffer;
temp->temperature = ds18b20_temp(data.spad);
temp->timestamp = data.timestamp;
}
else
{
return ret;
}
return buflen;
}
/****************************************************************************
* Name: ds18b20_control
*
* Description: Interface function of struct sensor_ops_s.
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_control(FAR struct sensor_lowerhalf_s *lower,
int cmd, unsigned long arg)
{
int ret;
struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
switch (cmd)
{
/* Read rom code */
case SNIOC_READROMCODE:
{
FAR uint64_t *ptr = (FAR uint64_t *)((uintptr_t)arg);
DEBUGASSERT(ptr != NULL);
*ptr = priv->config.romcode;
sninfo("read romcode: %16llx\n", *ptr);
ret = OK;
}
break;
/* Set new temperature alarm */
case SNIOC_SETALARM:
{
FAR struct ds18b20_alarm_s *ptr =
(FAR struct ds18b20_alarm_s *)((uintptr_t)arg);
DEBUGASSERT(ptr != NULL);
sninfo("set alarm: [TH/TL] = %d/%d °C\n", ptr->thigh, ptr->tlow);
ret = ds18b20_set_alarm(priv, ptr);
}
break;
/* Set sensor resolution */
case SNIOC_SETRESOLUTION:
{
uint8_t res = arg - 9;
sninfo("set resolution: %ld\n", arg);
if (res >= DS18B20_RESMIN && res <= DS18B20_RESMAX)
{
ret = ds18b20_set_res(priv, DS18B20_RES_CONV(res));
}
else
{
ret = -EINVAL;
}
}
break;
default:
snerr("ERROR: Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Name: ds18b20_active
*
* Description: Interface function of struct sensor_ops_s.
*
* Return:
* OK - on success
****************************************************************************/
static int ds18b20_active(FAR struct sensor_lowerhalf_s *lower,
unsigned char enabled)
{
#ifdef CONFIG_SENSORS_DS18B20_POLL
bool start_thread = false;
struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
if (enabled)
{
if (!priv->sensor.enabled)
{
start_thread = true;
}
}
priv->sensor.enabled = enabled;
if (start_thread == true)
{
/* Wake up the thread */
nxsem_post(&priv->run);
}
#endif
return OK;
}
/****************************************************************************
* Name: ds18b20_set_interval
*
* Description: Interface function of struct sensor_ops_s.
*
* Return:
* OK - on success
****************************************************************************/
#ifdef CONFIG_SENSORS_DS18B20_POLL
static int ds18b20_set_interval(FAR struct sensor_lowerhalf_s *lower,
FAR unsigned int *period_us)
{
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
priv->interval = *period_us;
return OK;
}
#endif
/****************************************************************************
* Name: ds18b20_thread
*
* Description: Thread for performing interval measurement cycle and data
* read.
*
* Parameter:
* argc - Number opf arguments
* argv - Pointer to argument list
****************************************************************************/
#ifdef CONFIG_SENSORS_DS18B20_POLL
static int ds18b20_thread(int argc, char** argv)
{
uint16_t orawdata;
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)
((uintptr_t)strtoul(argv[1], NULL, 0));
/* Set initial value to out of measurement range to ensure that the first
* data read leads to an upper notification.
*/
orawdata = 0xffff;
while (true)
{
int ret;
struct ds18b20_sensor_data_s data;
FAR struct ds18b20_sensor_s *sensor = &priv->sensor;
FAR struct ds18b20_alarm_s *alarm = &priv->reg.alarm;
if (!sensor->enabled)
{
/* Waiting to be woken up */
nxsem_wait(&priv->run);
}
if (alarm->wakeup == true)
{
/* Perform a temperature conversion to update the alarm flag */
ret = ds18b20_measure(priv);
if (!ret)
{
/* Wait until temperature conversion is done and the alarm flag
* is up to date.
*/
nxsig_usleep(g_res_timeout[DS18B20_RES_VAL(priv->reg.res)]);
/* Check for existing temperature alarm */
ret = ds18b20_isalarm(priv->master, &priv->config);
if (ret == 1)
{
ret = ds18b20_measure_read(priv, &data);
if (!ret && sensor->enabled == true)
{
/* Notify upper */
ds18b20_notify(priv, &data);
}
}
}
}
else
{
/* Default nofitication when temperature has been changed */
ret = ds18b20_measure_read(priv, &data);
if (!ret)
{
uint16_t rawtemp = ds18b20_rawtemp(data.spad);
if (sensor->enabled == true && orawdata != rawtemp)
{
ds18b20_notify(priv, &data);
}
/* Store the last sensor data for later comparison */
orawdata = ds18b20_rawtemp(data.spad);
}
}
/* Sleeping thread before fetching the next sensor data */
nxsig_usleep(priv->interval);
}
return OK;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ds18b20_register
*
* Description:
* Register the DS18B20 character device.
*
* Input Parameters:
* devno - The user specifies device number, from 0.
* onewire - An instance of the 1wire interface to communicate with DS18B20
* sensor.
* romcode - The ROM code of the DS18B20.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
****************************************************************************/
int ds18b20_register(int devno, FAR struct onewire_master_s *onewire,
uint64_t romcode)
{
int ret;
struct ds18b20_sensor_s *tmp;
#ifdef CONFIG_SENSORS_DS18B20_POLL
FAR char *argv[2];
char arg1[32];
#endif
/* Sanity check */
if (!onewire)
{
snerr("Invalid 1wire instance\n");
return -EINVAL;
}
/* Initialize the DS18B20 device structure */
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)
kmm_malloc(sizeof(struct ds18b20_dev_s));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->master = onewire;
priv->config.romcode = romcode;
priv->config.family = DS18B20_DEVICE_FAMILY;
priv->reg.res = DS18B20_RES_CONV(DS18B20_RESMAX);
priv->reg.alarm.thigh = DS18B20_TALARM_MAX;
priv->reg.alarm.tlow = DS18B20_TALARM_MIN;
#ifdef CONFIG_SENSORS_DS18B20_POLL
priv->reg.alarm.wakeup = false;
priv->interval = CONFIG_SENSORS_DS18B20_POLL_INTERVAL;
nxsem_init(&priv->run, 0, 0);
nxsem_set_protocol(&priv->run, SEM_PRIO_NONE);
#endif
/* Temperature register */
tmp = &priv->sensor;
#ifdef CONFIG_SENSORS_DS18B20_POLL
tmp->enabled = false;
#endif
tmp->lower.ops = &g_ds18b20_ops;
tmp->lower.type = SENSOR_TYPE_AMBIENT_TEMPERATURE;
tmp->lower.uncalibrated = false;
tmp->lower.buffer_number = 1;
ret = sensor_register(&tmp->lower, devno);
if (ret < 0)
{
goto sensor_err;
}
#ifdef CONFIG_SENSORS_DS18B20_POLL
/* Create thread for polling sensor data */
snprintf(arg1, 16, "0x%" PRIxPTR, (uintptr_t)priv);
argv[0] = arg1;
argv[1] = NULL;
ret = kthread_create("ds18b20_thread", SCHED_PRIORITY_DEFAULT,
CONFIG_SENSORS_DS18B20_THREAD_STACKSIZE,
ds18b20_thread, argv);
if (ret > 0)
#endif
{
return OK;
}
sensor_err:
sensor_unregister(&priv->sensor.lower, devno);
kmm_free(priv);
return ret;
}
#endif /* CONFIG_1WIRE && CONFIG_SENSORS_DS18B20 */

95
include/nuttx/sensors/ds18b20.h Normal file
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@ -0,0 +1,95 @@
/****************************************************************************
* include/nuttx/sensors/ds18b20.h
* Character driver for DS18B20 Digital Temperature Module.
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_SENSORS_DS18B20_H
#define __INCLUDE_NUTTX_SENSORS_DS18B20_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_1WIRE) && defined(CONFIG_SENSORS_DS18B20)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define DS18B20_DEVICE_FAMILY (0x28)
#define DS18B20_CMD_CONVERTT (0x44)
#define DS18B20_CMD_COPYSPAD (0x48)
#define DS18B20_CMD_RECALL (0xb8)
#define DS18B20_CMD_READPOWS (0xb4)
/****************************************************************************
* Public Types
****************************************************************************/
struct onewire_master_s;
struct ds18b20_alarm_s
{
int8_t thigh; /* Upper alarm temperature */
int8_t tlow; /* Lower alarm temperature */
# ifdef CONFIG_SENSORS_DS18B20_POLL
bool wakeup; /* Wakeup poll requests only when alarm detected */
# endif
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: ds18b20_register
*
* Description:
* Register the DS18B20 character device.
*
* Input Parameters:
* devno - The user specifies device number, from 0.
* onewire - An instance of the 1wire interface to communicate with DS18B20
* sensor.
* romcode - The ROM code of the DS18B20.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
****************************************************************************/
int ds18b20_register(int devno, FAR struct onewire_master_s *dev,
uint64_t romcode);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_1WIRE && CONFIG_SENSORS_DS18B20 */
#endif /* __INCLUDE_NUTTX_SENSORS_DS18B20_H */

17
include/nuttx/sensors/ioctl.h
View File

@ -229,26 +229,33 @@
#define SNIOC_READADDR SNIOC_READID /* Arg: uint8_t* pointer */
/* IOCTL commands unique to the DS18B20 */
/* SNIOC_SETRESOLUTION */ /* Arg: uint8_t value */
#define SNIOC_READROMCODE _SNIOC(0x0067) /* Arg: uint64_t* pointer */
#define SNIOC_SETALARM _SNIOC(0x0068) /* Arg: struct ds18b20_alarm_s* */
/* Command: SNIOC_ACTIVATE
* Description: Enable or disable sensor
* Argument: true or false.
*/
#define SNIOC_ACTIVATE _SNIOC(0x0067)
#define SNIOC_ACTIVATE _SNIOC(0x0080)
/* Command: SNIOC_SET_INTERVAL
* Description: Set interval between samples
* Argument: This is the interval pointer, in microseconds
*/
#define SNIOC_SET_INTERVAL _SNIOC(0x0068)
#define SNIOC_SET_INTERVAL _SNIOC(0x0081)
/* Command: SNIOC_BATCH
* Description: Set batch latency between batch data.
* Argument: This is the latency pointer, in microseconds
*/
#define SNIOC_BATCH _SNIOC(0x0069)
#define SNIOC_BATCH _SNIOC(0x0082)
/* Command: SNIOC_GET_NEVENTBUF
* Description: the number of sensor events that sensor buffer of upper half
@ -265,7 +272,7 @@
* See sensor.h(struct sensor_lower_half_s buffer_bytes).
*/
#define SNIOC_GET_NEVENTBUF _SNIOC(0x0070)
#define SNIOC_GET_NEVENTBUF _SNIOC(0x0083)
/* Command: SNIOC_SET_BUFFER_NUMBER
* Description: Set the number of events intermediate circualr buffer can
@ -275,6 +282,6 @@
* circualr buffer can hold by this ioctl command.
*/
#define SNIOC_SET_BUFFER_NUMBER _SNIOC(0x0071)
#define SNIOC_SET_BUFFER_NUMBER _SNIOC(0x0084)
#endif /* __INCLUDE_NUTTX_SENSORS_IOCTL_H */