簡介

使用氣體傳感器，對接到sensor框架中使用。

Sensor框架結構

device框架 --》sensor框架 --》具體的設備

函數說明

rt_device_find

查找設備時的名稱為sensor.c文件中的sensor_name_str變量定義的頭部分。

static char *const sensor_name_str[] =
{"none","acce_",     /* Accelerometer     */"gyro_",     /* Gyroscope         */"mag_",      /* Magnetometer      */"temp_",     /* Temperature       */"humi_",     /* Relative Humidity */"baro_",     /* Barometer         */"li_",       /* Ambient light     */"pr_",       /* Proximity         */"hr_",       /* Heart Rate        */"tvoc_",     /* TVOC Level        */"noi_",      /* Noise Loudness    */"step_",     /* Step sensor       */"forc_",     /* Force sensor      */"dust_",     /* Dust sensor       */"eco2_",     /* eCO2 sensor       */"gnss_",     /* GPS/GNSS sensor   */
//    "tof_",      /* TOF sensor        */
//    "spo2_"      /* SpO2 sensor       */"ch4_"       /* CH4  sensor       */
};

在注冊的時候，將后半部分的名稱寫入進去

result = rt_hw_sensor_register(sensor_temp,"gas", RT_DEVICE_FLAG_RDONLY, RT_NULL);

在該函數中通過調用初始化的時候的設備類型地址，對設備名稱的前部分進行查表注冊。

sensor_name = sensor_name_str[sensor->info. Type];#define RT_SENSOR_CLASS_NONE           (0)
#define RT_SENSOR_CLASS_ACCE           (1)  /* Accelerometer     */
#define RT_SENSOR_CLASS_GYRO           (2)  /* Gyroscope         */
#define RT_SENSOR_CLASS_MAG            (3)  /* Magnetometer      */
#define RT_SENSOR_CLASS_TEMP           (4)  /* Temperature       */
#define RT_SENSOR_CLASS_HUMI           (5)  /* Relative Humidity */
#define RT_SENSOR_CLASS_BARO           (6)  /* Barometer         */
#define RT_SENSOR_CLASS_LIGHT          (7)  /* Ambient light     */
#define RT_SENSOR_CLASS_PROXIMITY      (8)  /* Proximity         */
#define RT_SENSOR_CLASS_HR             (9)  /* Heart Rate        */
#define RT_SENSOR_CLASS_TVOC           (10) /* TVOC Level        */
#define RT_SENSOR_CLASS_NOISE          (11) /* Noise Loudness    */
#define RT_SENSOR_CLASS_STEP           (12) /* Step sensor       */
#define RT_SENSOR_CLASS_FORCE          (13) /* Force sensor      */
#define RT_SENSOR_CLASS_DUST           (14) /* Dust sensor       */
#define RT_SENSOR_CLASS_ECO2           (15) /* eCO2 sensor       */
#define RT_SENSOR_CLASS_GNSS           (16) /* GPS/GNSS sensor   */
#define RT_SENSOR_CLASS_CH4            (17) /* CH4 sensor        */

rt_device_open

該參數通過sensor，c中的下列函數實現的

/* RT-Thread Device Interface */
static rt_err_t rt_sensor_open(rt_device_t dev, rt_uint16_t oflag)
{rt_sensor_t sensor = (rt_sensor_t)dev;RT_ASSERT(dev != RT_NULL);rt_err_t res = RT_EOK;rt_err_t (*local_ctrl)(struct rt_sensor_device *sensor, int cmd, void *arg) =  local_control;if (sensor->module){/* take the module mutex */rt_mutex_take(sensor->module->lock, RT_WAITING_FOREVER);}if (sensor->module != RT_NULL && sensor->info.fifo_max > 0 && sensor->data_buf == RT_NULL){/* Allocate memory for the sensor buffer */sensor->data_buf = rt_malloc(sizeof(struct rt_sensor_data) * sensor->info.fifo_max);if (sensor->data_buf == RT_NULL){res = -RT_ENOMEM;goto __exit;}}if (sensor->ops->control != RT_NULL){local_ctrl = sensor->ops->control;}sensor->config.mode = RT_SENSOR_MODE_POLLING;if (oflag & RT_DEVICE_FLAG_RDONLY && dev->flag & RT_DEVICE_FLAG_RDONLY){/* If polling mode is supported, configure it to polling mode */local_ctrl(sensor, RT_SENSOR_CTRL_SET_MODE, (void *)RT_SENSOR_MODE_POLLING);}else if (oflag & RT_DEVICE_FLAG_INT_RX && dev->flag & RT_DEVICE_FLAG_INT_RX){/* If interrupt mode is supported, configure it to interrupt mode */if (local_ctrl(sensor, RT_SENSOR_CTRL_SET_MODE, (void *)RT_SENSOR_MODE_INT) == RT_EOK){/* Initialization sensor interrupt */rt_sensor_irq_init(sensor);sensor->config.mode = RT_SENSOR_MODE_INT;}}else if (oflag & RT_DEVICE_FLAG_FIFO_RX && dev->flag & RT_DEVICE_FLAG_FIFO_RX){/* If fifo mode is supported, configure it to fifo mode */if (local_ctrl(sensor, RT_SENSOR_CTRL_SET_MODE, (void *)RT_SENSOR_MODE_FIFO) == RT_EOK){/* Initialization sensor interrupt */rt_sensor_irq_init(sensor);sensor->config.mode = RT_SENSOR_MODE_FIFO;}}else{res = -RT_EINVAL;goto __exit;}/* Configure power mode to normal mode */if (local_ctrl(sensor, RT_SENSOR_CTRL_SET_POWER, (void *)RT_SENSOR_POWER_NORMAL) == RT_EOK){sensor->config.power = RT_SENSOR_POWER_NORMAL;}__exit:if (sensor->module){/* release the module mutex */rt_mutex_release(sensor->module->lock);}return res;
}

可以看到實際上，開啟函數是對control函數進行的控制，實現的開啟和關閉。

rt_device_read

該函數的輸入參數是struct rt_sensor_data data;

struct rt_sensor_data
{rt_uint32_t         timestamp;          /* The timestamp when the data was received */rt_uint8_t          type;               /* The sensor type of the data */rt_uint8_t          state;              /* The sensor state*/union{struct sensor_3_axis acce;          /* Accelerometer.       unit: mG          */struct sensor_3_axis gyro;          /* Gyroscope.           unit: mdps        */struct sensor_3_axis mag;           /* Magnetometer.        unit: mGauss      */struct coordinates   coord;         /* Coordinates          unit: degrees     */float                temp;          /* Temperature.         unit: dCelsius    */float                humi;          /* Relative humidity.   unit: permillage  */rt_int32_t           baro;          /* Pressure.            unit: pascal (Pa) */rt_int32_t           light;         /* Light.               unit: lux         */rt_int32_t           proximity;     /* Distance.            unit: centimeters */rt_int32_t           hr;            /* Heart rate.          unit: bpm         */rt_int32_t           tvoc;          /* TVOC.                unit: permillage  */rt_int32_t           noise;         /* Noise Loudness.      unit: HZ          */rt_uint32_t          step;          /* Step sensor.         unit: 1           */rt_int32_t           force;         /* Force sensor.        unit: mN          */rt_uint32_t          dust;          /* Dust sensor.         unit: ug/m3       */rt_uint32_t          eco2;          /* eCO2 sensor.         unit: ppm         */rt_uint8_t           ch4;           /* CH4  sensor.         unit: LEL         */} data;
};

在實際使用的時候，根據具體的傳感器選擇具體的數據類型進行選擇。在編寫底層對接函數的時候，在獲取數據部分也需要同步將數據寫入到相同的傳感器類型的數據中去。