Merge branch 'refactor/i2c_cxx_align_example' into 'master'

C++ I2C example now uses MPU9250 intead of MCP9808

See merge request espressif/esp-idf!15991

examples/cxx/experimental/experimental_cpp_component/include/i2c_cxx.hpp

@@ -229,7 +229,7 @@ public:
     std::vector<uint8_t> sync_read(uint8_t i2c_addr, size_t n_bytes);
 
     /**
-     * Do a simple asynchronous write-read transfer.
+     * Do a simple synchronous write-read transfer.
      *
      * First, \c write_data will be written to the bus, then a number of \c read_n_bytes will be read from the bus
      * with a repeated start condition. The slave device is determined by \c i2c_addr.

examples/cxx/experimental/sensor_mcp9808/README.md

@@ -1,49 +0,0 @@
-# Example: C++ I2C sensor read for MCP9808
-
-(See the README.md file in the upper level 'examples' directory for more information about examples.)
-
-This example demonstrates usage of C++ exceptions in ESP-IDF.
-
-In this example, the `sdkconfig.defaults` file sets the `CONFIG_COMPILER_CXX_EXCEPTIONS` option. 
-This enables both compile time support (`-fexceptions` compiler flag) and run-time support for C++ exception handling.
-This is necessary for the C++ I2C API.
-
-## How to use example
-
-### Hardware Required
-
-An MCP9808 sensor and any commonly available ESP32 development board.
-Pullups aren't necessary as the default pullups are enabled in the I2CMaster class.
-
-### Configure the project
-
-```
-idf.py menuconfig
-```
-
-### Build and Flash
-
-```
-idf.py -p PORT flash monitor
-```
-
-(Replace PORT with the name of the serial port.)
-
-(To exit the serial monitor, type ``Ctrl-]``.)
-
-See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
-
-## Example Output
-
-If the sensor is read correctly:
-
-```
-Current temperature: 24.875
-```
-
-If something went wrong:
-```
-I2C Exception with error: ESP_FAIL (-1)
-Coulnd't read sensor!
-```
-

examples/cxx/experimental/sensor_mcp9808/main/CMakeLists.txt

@@ -1,2 +0,0 @@
-idf_component_register(SRCS "sensor_mcp9808.cpp"
-                    INCLUDE_DIRS ".")

examples/cxx/experimental/sensor_mcp9808/main/sensor_mcp9808.cpp

@@ -1,54 +0,0 @@
-/* ESP MCP9808 Sensor/I2C C++ Example
-
-   This example code is in the Public Domain (or CC0 licensed, at your option.)
-
-   Unless required by applicable law or agreed to in writing, this
-   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
-   CONDITIONS OF ANY KIND, either express or implied.
-*/
-
-#include <iostream>
-#include "i2c_cxx.hpp"
-
-using namespace std;
-using namespace idf;
-
-#define ADDR 0x18
-#define I2C_MASTER_NUM I2C_NUM_0   /*!< I2C port number for master dev */
-#define I2C_MASTER_SCL_IO    19    /*!< gpio number for I2C master clock */
-#define I2C_MASTER_SDA_IO    18    /*!< gpio number for I2C master data  */
-
-#define MCP_9808_TEMP_REG 0x05
-
-/**
- * Calculates the temperature of the MCP9808 from the read msb and lsb. Loosely adapted from the MCP9808's datasheet.
- */
-float calc_temp(uint8_t msb, uint8_t lsb) {
-    float temperature;
-    msb &= 0x1F;
-    bool sign = msb & 0x10;
-    if (sign) {
-        msb &= 0x0F;
-        temperature = 256 - (msb * 16 + (float) lsb / 16);
-    } else {
-        temperature = (msb * 16 + (float) lsb / 16);
-    }
-
-    return temperature;
-}
-
-extern "C" void app_main(void)
-{
-    try {
-        // creating master bus, writing temperature register pointer and reading the value
-        shared_ptr<I2CMaster> master(new I2CMaster(I2C_MASTER_NUM, I2C_MASTER_SCL_IO, I2C_MASTER_SDA_IO, 400000));
-        master->sync_write(ADDR, {MCP_9808_TEMP_REG});
-        vector<uint8_t> data = master->sync_read(ADDR, 2);
-
-        cout << "Current temperature: " << calc_temp(data[0], data[1]) << endl;
-    } catch (const I2CException &e) {
-        cout << "I2C Exception with error: "  << e.what();
-        cout << " (" << e.error<< ")" << endl;
-        cout << "Coulnd't read sensor!" << endl;
-    }
-}

examples/cxx/experimental/simple_i2c_rw_example/CMakeLists.txt

@@ -5,4 +5,4 @@ cmake_minimum_required(VERSION 3.5)
 set(EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/examples/cxx/experimental/experimental_cpp_component")
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
-project(sensor_mcp9808)
+project(simple_i2c_rw_example)

examples/cxx/experimental/simple_i2c_rw_example/README.md

@@ -0,0 +1,60 @@
+# Example: C++ I2C sensor read for MPU9250
+
+(See the README.md file in the upper level 'examples' directory for more information about examples.)
+
+This example demonstrates usage of C++ exceptions in ESP-IDF. It is the C++ equivalent to the [I2C Simple Example](../../../peripherals/i2c/i2c_simple/) which is written in C.
+
+In this example, the `sdkconfig.defaults` file sets the `CONFIG_COMPILER_CXX_EXCEPTIONS` option. This enables both compile time support (`-fexceptions` compiler flag) and run-time support for C++ exception handling. This is necessary for the C++ I2C API.
+
+## How to Use This Example
+
+### Hardware Required
+
+To run this example, you should have one ESP32, ESP32-S series or ESP32-C series based development board as well as an MPU9250. MPU9250 is an inertial measurement unit, which contains an accelerometer, gyroscope as well as a magnetometer, for more information about it, you can read the [datasheet of the MPU9250 sensor](https://invensense.tdk.com/wp-content/uploads/2015/02/PS-MPU-9250A-01-v1.1.pdf).
+
+#### Pin Assignment:
+
+**Note:** The following pin assignments are used by default, you can change these in the `menuconfig` .
+
+|                  | SDA             | SCL           |
+| ---------------- | -------------- | -------------- |
+| ESP I2C Master   | I2C_MASTER_SDA | I2C_MASTER_SCL |
+| MPU9250 Sensor   | SDA            | SCL            |
+
+
+For the actual default value of `I2C_MASTER_SDA` and `I2C_MASTER_SCL`, see `Example Configuration` in `menuconfig`.
+
+**Note:** There's no need to add external pull-up resistors for SDA/SCL pins, because the driver will enable the internal pull-up resistors.
+
+### Configure the project
+
+```
+idf.py menuconfig
+```
+
+### Build and Flash
+
+```
+idf.py -p <PORT> flash monitor
+```
+
+Replace <PORT> with the name of the serial port. To exit the serial monitor, type ``Ctrl-]``.
+
+See the [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html) for full steps to configure and use ESP-IDF to build projects.
+
+## Example Output
+
+If the sensor is read correctly:
+
+```bash
+I (328) i2c-simple-example: I2C initialized successfully
+I (338) i2c-simple-example: WHO_AM_I = 71
+I (338) i2c-simple-example: I2C de-initialized successfully
+```
+
+If something went wrong:
+```
+I2C Exception with error: ESP_FAIL (-1)
+Couldn't read sensor!
+```
+

examples/cxx/experimental/simple_i2c_rw_example/main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "simple_i2c_rw_example.cpp"
+                    INCLUDE_DIRS ".")

examples/cxx/experimental/simple_i2c_rw_example/main/Kconfig.projbuild

@@ -0,0 +1,17 @@
+menu "Example Configuration"
+
+    config I2C_MASTER_SCL
+        int "SCL GPIO Num"
+        default 6 if IDF_TARGET_ESP32C3
+        default 19 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3
+        help
+            GPIO number for I2C Master clock line.
+
+    config I2C_MASTER_SDA
+        int "SDA GPIO Num"
+        default 5 if IDF_TARGET_ESP32C3
+        default 18 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3
+        help
+            GPIO number for I2C Master data line.
+
+endmenu

examples/cxx/experimental/simple_i2c_rw_example/main/simple_i2c_rw_example.cpp

@@ -0,0 +1,54 @@
+/*
+ * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: CC0
+ *
+ * MPU9250 I2C Sensor C++ Example
+ *
+ * This example code is in the Public Domain (or CC0 licensed, at your option.)
+ *
+ * Unless required by applicable law or agreed to in writing, this
+ * software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+#include <iostream>
+#include "esp_log.h"
+#include "i2c_cxx.hpp"
+
+using namespace std;
+using namespace idf;
+
+static const char *TAG = "i2c-cxx-simple-example";
+
+#define I2C_MASTER_NUM              0   /*!< I2C master i2c port number, the number of i2c peripheral interfaces
+                                             available will depend on the chip */
+#define I2C_MASTER_SCL_IO           CONFIG_I2C_MASTER_SCL      /*!< GPIO number used for I2C master clock */
+#define I2C_MASTER_SDA_IO           CONFIG_I2C_MASTER_SDA      /*!< GPIO number used for I2C master data  */
+
+#define MPU9250_SENSOR_ADDR                 0x68        /*!< Slave address of the MPU9250 sensor */
+#define MPU9250_WHO_AM_I_REG_ADDR           0x75        /*!< Register addresses of the "who am I" register */
+
+extern "C" void app_main(void)
+{
+    try {
+        // creating master bus
+        shared_ptr<I2CMaster> master(new I2CMaster(I2C_MASTER_NUM, I2C_MASTER_SCL_IO, I2C_MASTER_SDA_IO, 400000));
+        ESP_LOGI(TAG, "I2C initialized successfully");
+
+        // writing the pointer to the WHO_AM_I register to the device
+        master->sync_write(MPU9250_SENSOR_ADDR, {MPU9250_WHO_AM_I_REG_ADDR});
+
+        // reading back the value of WHO_AM_I register which should be 71
+        vector<uint8_t> data = master->sync_read(MPU9250_SENSOR_ADDR, 2);
+
+        ESP_LOGI(TAG, "WHO_AM_I = %X", data[0]);
+    } catch (const I2CException &e) {
+        cout << "I2C Exception with error: "  << e.what();
+        cout << " (" << e.error<< ")" << endl;
+        cout << "Couldn't read sensor!" << endl;
+    }
+
+    // The I2CMaster object is de-initialized in its destructor when going out of scope.
+    ESP_LOGI(TAG, "I2C de-initialized successfully");
+}

examples/cxx/experimental/simple_spi_rw_example/README.md

@@ -53,7 +53,7 @@ If there's an error with the SPI peripheral:
 ...
 I (0) cpu_start: Starting scheduler on APP CPU.
 E (434) spi: spicommon_bus_initialize_io(429): mosi not valid
-Coulnd't read SPI!
+Couldn't read SPI!
 ```
 
 If the SPI pins are not connected properly, the resulting read may just return 0, this error can not be detected:

examples/cxx/experimental/simple_spi_rw_example/main/simple_spi_rw_example.cpp

@@ -43,6 +43,6 @@ extern "C" void app_main(void)
         this_thread::sleep_for(std::chrono::seconds(2));
 
     } catch (const SPIException &e) {
-        cout << "Coulnd't read SPI!" << endl;
+        cout << "Couldn't read SPI!" << endl;
     }
 }

examples/peripherals/i2c/i2c_simple/README.md

@@ -12,7 +12,7 @@ If you have a new I2C application to go (for example, read the temperature data
 
 ### Hardware Required
 
-To run this example, you should have one ESP32, ESP32-S or ESP32-C based development board as well as a MPU9250. MPU9250 is a inertial measurement unit, which contains a accelerometer, gyroscope as well as a magnetometer, for more information about it, you can read the [PDF](https://invensense.tdk.com/wp-content/uploads/2015/02/PS-MPU-9250A-01-v1.1.pdf) of this sensor.
+To run this example, you should have one ESP32, ESP32-S or ESP32-C based development board as well as a MPU9250. MPU9250 is a inertial measurement unit, which contains a accelerometer, gyroscope as well as a magnetometer, for more information about it, you can read the [datasheet of the MPU9250 sensor](https://invensense.tdk.com/wp-content/uploads/2015/02/PS-MPU-9250A-01-v1.1.pdf).
 
 #### Pin Assignment:
 
@@ -26,7 +26,7 @@ To run this example, you should have one ESP32, ESP32-S or ESP32-C based develop
 
 For the actual default value of `I2C_MASTER_SDA` and `I2C_MASTER_SCL` see `Example Configuration` in `menuconfig`.
 
-**Note: ** There’s no need to add an external pull-up resistors for SDA/SCL pin, because the driver will enable the internal pull-up resistors.
+**Note:** There's no need to add an external pull-up resistors for SDA/SCL pin, because the driver will enable the internal pull-up resistors.
 
 ### Build and Flash
 
@@ -41,7 +41,7 @@ See the [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/l
 ```bash
 I (328) i2c-simple-example: I2C initialized successfully
 I (338) i2c-simple-example: WHO_AM_I = 71
-I (338) i2c-simple-example: I2C unitialized successfully
+I (338) i2c-simple-example: I2C de-initialized successfully
 ```
 
 ## Troubleshooting

examples/peripherals/i2c/i2c_simple/main/i2c_simple_main.c

@@ -93,5 +93,5 @@ void app_main(void)
     ESP_ERROR_CHECK(mpu9250_register_write_byte(MPU9250_PWR_MGMT_1_REG_ADDR, 1 << MPU9250_RESET_BIT));
 
     ESP_ERROR_CHECK(i2c_driver_delete(I2C_MASTER_NUM));
-    ESP_LOGI(TAG, "I2C unitialized successfully");
+    ESP_LOGI(TAG, "I2C de-initialized successfully");
 }