Chip Id Retry functionality added.

[BME280_driver] / bme280.c

diff --git a/bme280.c b/bme280.c
index 7680242e8405914043c681464fb93098caeab258..f1bc1ae0357f0fa34b07cb8f789bda284104c48f 100644 (file)
--- a/bme280.c
+++ b/bme280.c
@@ -1,10 +1,10 @@
 /*
 ****************************************************************************
-* Copyright (C) 2013 - 2015 Bosch Sensortec GmbH
+* Copyright (C) 2015 - 2016 Bosch Sensortec GmbH
 *
 * bme280.c
-* Date: 2015/03/27
-* Revision: 2.0.4(Pressure and Temperature compensation code revision is 1.1
+* Date: 2016/07/04
+* Revision: 2.0.5(Pressure and Temperature compensation code revision is 1.1
 *               and Humidity compensation code revision is 1.0)
 *
 * Usage: Sensor Driver file for BME280 sensor
@@ -84,17 +84,35 @@ BME280_RETURN_FUNCTION_TYPE bme280_init(struct bme280_t *bme280)
        /* used to return the communication result*/
        BME280_RETURN_FUNCTION_TYPE com_rslt = ERROR;
        u8 v_data_u8 = BME280_INIT_VALUE;
+       u8 v_chip_id_read_count = BME280_CHIP_ID_READ_COUNT;
 
-       p_bme280 = bme280;
        /* assign BME280 ptr */
-       com_rslt = p_bme280->BME280_BUS_READ_FUNC(p_bme280->dev_addr,
-       BME280_CHIP_ID_REG, &v_data_u8,
-       BME280_GEN_READ_WRITE_DATA_LENGTH);
-       /* read Chip Id */
+       p_bme280 = bme280;
+
+       while (v_chip_id_read_count > 0) {
+
+               /* read Chip Id */
+               com_rslt = p_bme280->BME280_BUS_READ_FUNC(p_bme280->dev_addr,
+                               BME280_CHIP_ID_REG, &v_data_u8,
+                               BME280_GEN_READ_WRITE_DATA_LENGTH);
+               /* Check for the correct chip id */
+               if (v_data_u8 == BME280_CHIP_ID)
+                       break;
+               v_chip_id_read_count--;
+               /* Delay added concerning the low speed of power up system to
+               facilitate the proper reading of the chip ID */
+               p_bme280->delay_msec(BME280_REGISTER_READ_DELAY);
+       }
+       /*assign chip ID to the global structure*/
        p_bme280->chip_id = v_data_u8;
+       /*com_rslt status of chip ID read*/
+       com_rslt = (v_chip_id_read_count == BME280_INIT_VALUE) ?
+                       BME280_CHIP_ID_READ_FAIL : BME280_CHIP_ID_READ_SUCCESS;
 
-       com_rslt += bme280_get_calib_param();
-       /* readout bme280 calibparam structure */
+       if (com_rslt == BME280_CHIP_ID_READ_SUCCESS) {
+               /* readout bme280 calibparam structure */
+               com_rslt += bme280_get_calib_param();
+       }
        return com_rslt;
 }
 /*!
@@ -1824,7 +1842,7 @@ s32 *v_uncom_temperature_s32, s32 *v_uncom_humidity_s32)
        /* used to return the communication result*/
        BME280_RETURN_FUNCTION_TYPE com_rslt = ERROR;
        u8 v_data_u8 = BME280_INIT_VALUE;
-       u8 v_waittime_u8r = BME280_INIT_VALUE;
+       u8 v_waittime_u8 = BME280_INIT_VALUE;
        u8 v_prev_pow_mode_u8 = BME280_INIT_VALUE;
        u8 v_mode_u8r = BME280_INIT_VALUE;
        u8 pre_ctrl_config_value = BME280_INIT_VALUE;
@@ -1874,8 +1892,8 @@ s32 *v_uncom_temperature_s32, s32 *v_uncom_humidity_s32)
                                        BME280_CTRL_MEAS_REG,
                                &v_mode_u8r, BME280_GEN_READ_WRITE_DATA_LENGTH);
                        }
-                       bme280_compute_wait_time(&v_waittime_u8r);
-                       p_bme280->delay_msec(v_waittime_u8r);
+                       bme280_compute_wait_time(&v_waittime_u8);
+                       p_bme280->delay_msec(v_waittime_u8);
                        /* read the force-mode value of pressure
                        temperature and humidity*/
                        com_rslt +=
@@ -2033,7 +2051,7 @@ double bme280_compensate_pressure_double(s32 v_uncom_pressure_s32)
        ((double)p_bme280->cal_param.dig_P1);
        pressure = 1048576.0 - (double)v_uncom_pressure_s32;
        /* Avoid exception caused by division by zero */
-       if (v_x1_u32 != BME280_INIT_VALUE)
+       if ((v_x1_u32 > 0) || (v_x1_u32 < 0))
                pressure = (pressure - (v_x2_u32 / 4096.0)) * 6250.0 / v_x1_u32;
        else
                return BME280_INVALID_DATA;
@@ -2062,7 +2080,7 @@ double bme280_compensate_humidity_double(s32 v_uncom_humidity_s32)
        double var_h = BME280_INIT_VALUE;
 
        var_h = (((double)p_bme280->cal_param.t_fine) - 76800.0);
-       if (var_h != BME280_INIT_VALUE)
+       if ((var_h > 0) || (var_h < 0))
                var_h = (v_uncom_humidity_s32 -
                (((double)p_bme280->cal_param.dig_H4) * 64.0 +
                ((double)p_bme280->cal_param.dig_H5) / 16384.0 * var_h))*
@@ -2204,9 +2222,9 @@ BME280_RETURN_FUNCTION_TYPE bme280_compute_wait_time(u8
        >> BME280_SHIFT_BIT_POSITION_BY_01_BIT) +
        ((1 << p_bme280->oversamp_humidity)
        >> BME280_SHIFT_BIT_POSITION_BY_01_BIT))
-       + (p_bme280->oversamp_pressure ?
+       + ((p_bme280->oversamp_pressure > 0) ?
        T_SETUP_PRESSURE_MAX : 0) +
-       (p_bme280->oversamp_humidity ?
+       ((p_bme280->oversamp_humidity > 0) ?
        T_SETUP_HUMIDITY_MAX : 0) + 15) / 16;
        return com_rslt;
 }