Minor changes in BME680 driver (#543)

examples/bme680/bme680_heating_profiles/bme680_heating_profiles.c

@@ -103,10 +103,7 @@ void user_init(void)
 
     if (sensor)
     {
-        // Create a task that uses the sensor
+        /** -- SENSOR CONFIGURATION PART (optional) --- */
-        xTaskCreate(user_task, "user_task", 256, NULL, 2, NULL);
-
-        /** -- OPTIONAL PART -- */
 
         // Changes the oversampling rates to 4x oversampling for temperature
         // and 2x oversampling for humidity. Pressure measurement is skipped.
@@ -121,5 +118,15 @@ void user_init(void)
         bme680_set_heater_profile (sensor, 2, 300, 140);
         bme680_set_heater_profile (sensor, 3, 350, 160);
         bme680_set_heater_profile (sensor, 4, 400, 180);
+
+        /** -- TASK CREATION PART --- */
+
+        // must be done last to avoid concurrency situations with the sensor 
+        // configuration part
+
+        // Create a task that uses the sensor
+        xTaskCreate(user_task, "user_task", 256, NULL, 2, NULL);
     }
+    else
+        printf("Could not initialize BME680 sensor\n");
 }

examples/bme680/bme680_one_sensor/bme680_one_sensor.c

@@ -138,10 +138,7 @@ void user_init(void)
 
     if (sensor)
     {
-        // Create a task that uses the sensor
+        /** -- SENSOR CONFIGURATION PART (optional) --- */
-        xTaskCreate(user_task, "user_task", TASK_STACK_DEPTH, NULL, 2, NULL);
-
-        /** -- OPTIONAL PART -- */
 
         // Changes the oversampling rates to 4x oversampling for temperature
         // and 2x oversampling for humidity. Pressure measurement is skipped.
@@ -156,5 +153,15 @@ void user_init(void)
 
         // Set ambient temperature to 10 degree Celsius
         bme680_set_ambient_temperature (sensor, 10);
+            
+        /** -- TASK CREATION PART --- */
+
+        // must be done last to avoid concurrency situations with the sensor 
+        // configuration part
+
+        // Create a task that uses the sensor
+        xTaskCreate(user_task, "user_task", TASK_STACK_DEPTH, NULL, 2, NULL);
     }
+    else
+        printf("Could not initialize BME680 sensor\n");
 }

examples/bme680/bme680_two_sensors/bme680_two_sensors.c

@@ -1,7 +1,7 @@
 /**
  * Simple example with two sensors, one sensor connected to I2C bus 0 and
  * one sensor connected to SPI. It defines two different user tasks, one for
- * each sensor. It demonstrate the possible approaches to wait for measurement
+ * each sensor. It demonstrates the possible approaches to wait for measurement
  * results, active busy waiting using ```bme680_is_measuring``` and passive
  * waiting using *vTaskDelay*.
  *
@@ -128,13 +128,7 @@ void user_init(void)
 
     if (sensor1 && sensor2)
     {
-        // Create the tasks that use the sensors
+        /** -- SENSOR CONFIGURATION PART (optional) --- */
-        xTaskCreate(user_task_sensor1, "user_task_sensor1", 256, NULL, 2, 0);
-        xTaskCreate(user_task_sensor2, "user_task_sensor2", 256, NULL, 2, 0);
-
-        // That's it.
-
-        /** -- OPTIONAL PART -- */
 
         // Changes the oversampling rates for both sensor to different values
         bme680_set_oversampling_rates(sensor1, osr_4x, osr_2x, osr_1x);
@@ -151,5 +145,14 @@ void user_init(void)
         // Activate the heater profile 0
         bme680_use_heater_profile (sensor1, 0);
         bme680_use_heater_profile (sensor2, 0);
+
+        /** -- TASK CREATION PART --- */
+
+        // must be done last to avoid concurrency situations with the sensor 
+        // configuration part
+
+        // Create the tasks that use the sensors
+        xTaskCreate(user_task_sensor1, "user_task_sensor1", 256, NULL, 2, 0);
+        xTaskCreate(user_task_sensor2, "user_task_sensor2", 256, NULL, 2, 0);
     }
 }

extras/bme680/README.md

@@ -378,10 +378,7 @@ Optionally, you could wish to set some measurement parameters. For details see t
 ```
 if (sensor)
 {
-    // Create a task that uses the sensor
+    /** -- SENSOR CONFIGURATION PART (optional) --- */
-    xTaskCreate(user_task, "user_task", 256, NULL, 2, NULL);
-
-    /** -- OPTIONAL PART -- */
 
     // Changes the oversampling rates to 4x oversampling for temperature
     // and 2x oversampling for humidity. Pressure measurement is skipped.
@@ -394,11 +391,21 @@ if (sensor)
     bme680_set_heater_profile (sensor, 0, 200, 100);
     bme680_use_heater_profile (sensor, 0);
 
+    /** -- TASK CREATION PART --- */
+
+    // must be done last to avoid concurrency situations with the sensor 
+    // configuration part
+
+    // Create a task that uses the sensor
+    xTaskCreate(user_task, "user_task", TASK_STACK_DEPTH, NULL, 2, NULL);
+
     ...
 }
 ```
 
-Last, the user task that uses the sensor has to be created.
+Finally, a user task that uses the sensor has to be created.
+
+**Please note:** To avoid concurrency situations when driver functions are used to access the sensor, for example to read data, the user task must not be created until the sensor configuration is completed.
 
 
 ### User task
@@ -566,10 +573,7 @@ void user_init(void)
 
     if (sensor)
     {
-        // Create a task that uses the sensor
+        /** -- SENSOR CONFIGURATION PART (optional) --- */
-        xTaskCreate(user_task, "user_task", TASK_STACK_DEPTH, NULL, 2, NULL);
-
-        /** -- OPTIONAL PART -- */
 
         // Changes the oversampling rates to 4x oversampling for temperature
         // and 2x oversampling for humidity. Pressure measurement is skipped.
@@ -584,7 +588,17 @@ void user_init(void)
 
         // Set ambient temperature to 10 degree Celsius
         bme680_set_ambient_temperature (sensor, 10);
+            
+        /** -- TASK CREATION PART --- */
+
+        // must be done last to avoid concurrency situations with the sensor 
+        // configuration part
+
+        // Create a task that uses the sensor
+        xTaskCreate(user_task, "user_task", TASK_STACK_DEPTH, NULL, 2, NULL);
     }
+    else
+        printf("Could not initialize BME680 sensor\n");
 }
 ```
 

extras/bme680/bme680.c

@@ -305,8 +305,6 @@ bme680_sensor_t* bme680_init_sensor(uint8_t bus, uint8_t addr, uint8_t cs)
         free (dev);
         return NULL;
     }
-    if (!addr) 
-        spi_semaphore_init();
 
     // reset the sensor
     if (!bme680_reset(dev))
@@ -1278,14 +1276,11 @@ static bool bme680_spi_read(bme680_sensor_t* dev, uint8_t reg, uint8_t *data, ui
         return false;
     }
 
-    spi_semaphore_take ();
-
     // set mem page first
     if (!bme680_spi_set_mem_page (dev, reg))
     {
         error_dev ("Error on read from SPI slave on bus 1. Could not set mem page.",
                    __FUNCTION__, dev);
-        spi_semaphore_give ();
         return false;
     }
 
@@ -1304,11 +1299,8 @@ static bool bme680_spi_read(bme680_sensor_t* dev, uint8_t reg, uint8_t *data, ui
     {
         error_dev ("Could not read data from SPI", __FUNCTION__, dev);
         dev->error_code |= BME680_SPI_READ_FAILED;
-        spi_semaphore_give ();
         return false;
     }
-    spi_semaphore_give ();
-    
     // shift data one by left, first byte received while sending register address is invalid
     for (int i=0; i < len; i++)
       data[i] = miso[i+1];
@@ -1340,14 +1332,11 @@ static bool bme680_spi_write(bme680_sensor_t* dev, uint8_t reg, uint8_t *data, u
         return false;
     }
 
-    spi_semaphore_take ();
-    
     // set mem page first if not mem page register is used
     if (reg != BME680_REG_STATUS && !bme680_spi_set_mem_page (dev, reg))
     {
         error_dev ("Error on write from SPI slave on bus 1. Could not set mem page.",
                    __FUNCTION__, dev);
-        spi_semaphore_give ();
         return false;
     }
 
@@ -1371,10 +1360,8 @@ static bool bme680_spi_write(bme680_sensor_t* dev, uint8_t reg, uint8_t *data, u
     {
         error_dev ("Could not write data to SPI.", __FUNCTION__, dev);
         dev->error_code |= BME680_SPI_WRITE_FAILED;
-        spi_semaphore_give ();
         return false;
     }
-    spi_semaphore_give ();
 
     return true;
 }

extras/bme680/bme680_platform.c

@@ -0,0 +1,82 @@
+/*
+ * Driver for Bosch Sensortec BME680 digital temperature, humidity, pressure
+ * and gas sensor connected to I2C or SPI
+ *
+ * This driver is for the usage with the ESP8266 and FreeRTOS (esp-open-rtos)
+ * [https://github.com/SuperHouse/esp-open-rtos]. It is also working with ESP32
+ * and ESP-IDF [https://github.com/espressif/esp-idf.git] as well as Linux
+ * based systems using a wrapper library for ESP8266 functions.
+ *
+ * ---------------------------------------------------------------------------
+ *
+ * The BSD License (3-clause license)
+ *
+ * Copyright (c) 2017 Gunar Schorcht (https://github.com/gschorcht)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * Platform file: platform specific definitions, includes and functions
+ */
+
+#include "bme680_platform.h"
+
+// platform specific SPI functions
+
+static const spi_settings_t bus_settings = {
+    .mode         = SPI_MODE0,
+    .freq_divider = SPI_FREQ_DIV_1M,
+    .msb          = true,
+    .minimal_pins = false,
+    .endianness   = SPI_LITTLE_ENDIAN
+};
+
+bool spi_device_init (uint8_t bus, uint8_t cs)
+{
+    gpio_enable(cs, GPIO_OUTPUT);
+    gpio_write (cs, true);
+    return true;
+}
+
+size_t spi_transfer_pf(uint8_t bus, uint8_t cs, const uint8_t *mosi, uint8_t *miso, uint16_t len)
+{
+    spi_settings_t old_settings;
+
+    spi_get_settings(bus, &old_settings);
+    spi_set_settings(bus, &bus_settings);
+    gpio_write(cs, false);
+
+    size_t transfered = spi_transfer (bus, (const void*)mosi, (void*)miso, len, SPI_8BIT);
+
+    gpio_write(cs, true);
+    spi_set_settings(bus, &old_settings);
+    
+    return transfered;
+}
+

extras/bme680/bme680_platform.h

@@ -66,46 +66,14 @@
 #include "esp/spi.h"
 #include "i2c/i2c.h"
 
-// platform specific definitions
-
-#define spi_semaphore_init()
-#define spi_semaphore_take()
-#define spi_semaphore_give()
-
 // platform specific SPI functions
 
 #define spi_bus_init(bus,sck,miso,mosi) // not needed on ESP8266
 
-static const spi_settings_t bus_settings = {
+extern bool   spi_device_init (uint8_t bus, uint8_t cs);
-    .mode         = SPI_MODE0,
+extern size_t spi_transfer_pf (uint8_t bus, uint8_t cs,
-    .freq_divider = SPI_FREQ_DIV_1M,
+                               const uint8_t *mosi, uint8_t *miso,
-    .msb          = true,
+                               uint16_t len);
-    .minimal_pins = false,
-    .endianness   = SPI_LITTLE_ENDIAN
-};
-
-inline static bool spi_device_init (uint8_t bus, uint8_t cs)
-{
-    gpio_enable(cs, GPIO_OUTPUT);
-    gpio_write (cs, true);
-    return true;
-}
-
-inline static size_t spi_transfer_pf(uint8_t bus, uint8_t cs, const uint8_t *mosi, uint8_t *miso, uint16_t len)
-{
-    spi_settings_t old_settings;
-
-    spi_get_settings(bus, &old_settings);
-    spi_set_settings(bus, &bus_settings);
-    gpio_write(cs, false);
-
-    size_t transfered = spi_transfer (bus, (const void*)mosi, (void*)miso, len, SPI_8BIT);
-
-    gpio_write(cs, true);
-    spi_set_settings(bus, &old_settings);
-    
-    return transfered;
-}
 
 #endif // ESP_OPEN_RTOS