All experience with string

本文介绍了一种将字符串转换为数值类型的通用方法,并提供了一个C++模板函数实现。该函数能够根据指定的进制(十进制、十六进制等)进行转换。

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1.Convert string to numeric
#include <string>
#include <sstream>
#include <iostream>

// the third parameter of from_string() should be 
// one of std::hex, std::dec or std::oct
template <class T>
bool from_string(T& t,
                 const std::string& s,
                 std::ios_base& (*f)(std::ios_base&))  

   

/** * Copyright (C) Bosch Sensortec GmbH. All Rights Reserved. Confidential. * * Disclaimer * * Common: * Bosch Sensortec products are developed for the consumer goods industry. They may only be used * within the parameters of the respective valid product data sheet. Bosch Sensortec products are * provided with the express understanding that there is no warranty of fitness for a particular purpose. * They are not fit for use in life-sustaining, safety or security sensitive systems or any system or device * that may lead to bodily harm or property damage if the system or device malfunctions. In addition, * Bosch Sensortec products are not fit for use in products which interact with motor vehicle systems. * The resale and/or use of products are at the purchaser's own risk and his own responsibility. The * examination of fitness for the intended use is the sole responsibility of the Purchaser. * * The purchaser shall indemnify Bosch Sensortec from all third party claims, including any claims for * incidental, or consequential damages, arising from any product use not covered by the parameters of * the respective valid product data sheet or not approved by Bosch Sensortec and reimburse Bosch * Sensortec for all costs in connection with such claims. * * The purchaser must monitor the market for the purchased products, particularly with regard to * product safety and inform Bosch Sensortec without delay of all security relevant incidents. * * Engineering Samples are marked with an asterisk (*) or (e). Samples may vary from the valid * technical specifications of the product series. They are therefore not intended or fit for resale to third * parties or for use in end products. Their sole purpose is internal client testing. The testing of an * engineering sample may in no way replace the testing of a product series. Bosch Sensortec * assumes no liability for the use of engineering samples. By accepting the engineering samples, the * Purchaser agrees to indemnify Bosch Sensortec from all claims arising from the use of engineering * samples. * * Special: * This software module (hereinafter called "Software") and any information on application-sheets * (hereinafter called "Information") is provided free of charge for the sole purpose to support your * application work. The Software and Information is subject to the following terms and conditions: * * The Software is specifically designed for the exclusive use for Bosch Sensortec products by * personnel who have special experience and training. Do not use this Software if you do not have the * proper experience or training. * * This Software package is provided `` as is `` and without any expressed or implied warranties, * including without limitation, the implied warranties of merchantability and fitness for a particular * purpose. * * Bosch Sensortec and their representatives and agents deny any liability for the functional impairment * of this Software in terms of fitness, performance and safety. Bosch Sensortec and their * representatives and agents shall not be liable for any direct or indirect damages or injury, except as * otherwise stipulated in mandatory applicable law. * * The Information provided is believed to be accurate and reliable. Bosch Sensortec assumes no * responsibility for the consequences of use of such Information nor for any infringement of patents or * other rights of third parties which may result from its use. No license is granted by implication or * otherwise under any patent or patent rights of Bosch. Specifications mentioned in the Information are * subject to change without notice. * * It is not allowed to deliver the source code of the Software to any third party without permission of * Bosch Sensortec. * */ /*! * @file bsec_iot_example.c * * @brief * Example for using of BSEC library in a fixed configuration with the BME68x sensor. * This works by running an endless loop in the bsec_iot_loop() function. */ /*! * @addtogroup bsec_examples BSEC Examples * @brief BSEC usage examples * @{*/ /**********************************************************************************************************************/ /* header files */ /**********************************************************************************************************************/ #include "bsec_integration.h" /**********************************************************************************************************************/ /* functions */ /**********************************************************************************************************************/ /*! * @brief Write operation in either Wire or SPI * * param[in] reg_addr register address * param[in] reg_data_ptr pointer to the data to be written * param[in] data_len number of bytes to be written * param[in] intf_ptr interface pointer * * @return result of the bus communication function */ int8_t bus_write(uint8_t reg_addr, const uint8_t *reg_data_ptr, uint32_t data_len, void *intf_ptr) { // ... // Please insert system specific function to write to the bus where BME68x is connected // ... return 0; } /*! * @brief Read operation in either Wire or SPI * * param[in] reg_addr register address * param[out] reg_data_ptr pointer to the memory to be used to store the read data * param[in] data_len number of bytes to be read * param[in] intf_ptr interface pointer * * @return result of the bus communication function */ int8_t bus_read(uint8_t reg_addr, uint8_t *reg_data_ptr, uint32_t data_len, void *intf_ptr) { // ... // Please insert system specific function to read from bus where BME68x is connected // ... return 0; } /*! * @brief System specific implementation of sleep function * * @param[in] t_us Time in microseconds * @param[in] intf_ptr Pointer to the interface descriptor * * @return none */ void sleep_n(uint32_t t_us, void *intf_ptr) { // ... // Please insert system specific function sleep or delay for t_ms milliseconds // ... } /*! * @brief Capture the system time in microseconds * * @return system_current_time current system timestamp in microseconds */ int64_t get_timestamp_us() { int64_t system_current_time = 0; // ... // Please insert system specific function to retrieve a timestamp (in microseconds) // ... return system_current_time; } /*! * @brief Handling of the ready outputs * * @param[in] outputs output_t structure * @param[in] bsec_status value returned by the bsec_do_steps() call * * @return none */ void output_ready(output_t *outputs, bsec_library_return_t bsec_status) { // ... // Please insert system specific code to further process or display the BSEC outputs // ... } /*! * @brief Load previous library state from non-volatile memory * * @param[in,out] state_buffer buffer to hold the loaded state string * @param[in] n_buffer size of the allocated state buffer * * @return number of bytes copied to state_buffer */ uint32_t state_load(uint8_t *state_buffer, uint32_t n_buffer) { // ... // Load a previous library state from non-volatile memory, if available. // // Return zero if loading was unsuccessful or no state was available, // otherwise return length of loaded state string. // ... return 0; } /*! * @brief Save library state to non-volatile memory * * @param[in] state_buffer buffer holding the state to be stored * @param[in] length length of the state string to be stored * * @return none */ void state_save(const uint8_t *state_buffer, uint32_t length) { // ... // Save the string some form of non-volatile memory, if possible. // ... } /*! * @brief Load library config from non-volatile memory * * @param[in,out] config_buffer buffer to hold the loaded state string * @param[in] n_buffer size of the allocated state buffer * * @return number of bytes copied to config_buffer */ uint32_t config_load(uint8_t *config_buffer, uint32_t n_buffer) { // ... // Load a library config from non-volatile memory, if available. // // Return zero if loading was unsuccessful or no config was available, // otherwise return length of loaded config string. // ... return 0; } /*! * @brief Main function which configures BSEC library and then reads and processes the data from sensor based * on timer ticks * * @return result of the processing */ int main() { return_values_init ret; struct bme68x_dev bme_dev; memset(&bme_dev,0,sizeof(bme_dev)); /* Call to the function which initializes the BSEC library * Switch on low-power mode and provide no temperature offset */ ret = bsec_iot_init(BSEC_SAMPLE_RATE_LP, 0.0f, bus_write, bus_read, sleep_n, state_load, config_load, bme_dev, 0); if (ret.bme68x_status) { /* Could not intialize BME68x */ return (int)ret.bme68x_status; } else if (ret.bsec_status) { /* Could not intialize BSEC library */ return (int)ret.bsec_status; } /* Call to endless loop function which reads and processes data based on sensor settings */ /* State is saved every 10.000 samples, which means every 10.000 * 3 secs = 500 minutes */ bsec_iot_loop(sleep_n, get_timestamp_us, output_ready, state_save, 10000); return 0; } /*! @}*/ 根据这个例程使用stm32hal库用keil开发
最新发布
07-25
在STM32 HAL库项目中集成BSEC库以支持BME68x传感器功能,并在Keil开发环境中配置和运行,需要完成以下步骤: ### 3.1 准备工作 - **获取BSEC库**:从博世的GitHub仓库下载BSEC库,地址为:https://github.com/BoschSensortec/BSEC-Arduino-library。尽管该库是为Arduino设计的,但可以将其移植到STM32项目中[^1]。 - **安装Keil MDK**:确保已经安装了Keil MDK开发环境,并且熟悉基本的项目创建和配置流程。 - **安装STM32CubeMX**:用于生成初始化代码,简化外设配置过程。 ### 3.2 创建STM32 HAL库项目 - **使用STM32CubeMX生成初始化代码**: - 打开STM32CubeMX,选择目标MCU(如STM32F103C8T6)。 - 配置时钟源、I2C接口(用于连接BME680传感器)、USART接口(用于调试输出)等外设。 - 生成代码并导入到Keil项目中。 ### 3.3 移植BSEC库到STM32项目 - **添加BSEC库文件**: - 将BSEC库中的源文件(如`bsec.cpp`、`bsec.h`)和相关依赖文件复制到Keil项目目录中。 - 在Keil项目中添加这些文件,确保编译器能够识别并编译这些文件。 - **修改BSEC库以适应STM32平台**: - **时间戳处理**:BSEC库需要一个时间戳函数来提供当前时间。在STM32 HAL库中,可以使用`HAL_GetTick()`函数来实现。修改BSEC库中的时间戳函数,使其调用`HAL_GetTick()`。 - **I2C通信接口**:BSEC库需要通过I2C接口与BME680传感器进行通信。需要实现`bsec_i2c_read`和`bsec_i2c_write`函数,使用HAL库中的`HAL_I2C_Master_Transmit`和`HAL_I2C_Master_Receive`函数来完成I2C读写操作。 ### 3.4 配置BSEC库 - **初始化BSEC库**: - 在主程序中初始化BSEC库,调用`bsec_init()`函数。 - 设置BSEC库的工作模式,例如`BSEC_MODE_CONTINUOUS`或`BSEC_MODE_BACKGROUND`。 - **设置传感器配置**: - 根据应用需求,设置传感器的采样率、工作模式等参数。 - 调用`bsec_set_configuration()`函数来应用这些配置。 ### 3.5 读取和处理传感器数据 - **读取传感器数据**: - 使用`bsec_do_steps()`函数来触发传感器数据采集和处理。 - 该函数会返回一个包含空气质量指数(IAQ)、气体电阻、温度、湿度等信息的结构体。 - **输出传感器数据**: - 通过USART接口将传感器数据打印到串口调试工具中,便于调试和验证。 ### 3.6 优化和调试 - **优化内存使用**: - BSEC库可能会占用较多的Flash和RAM资源,特别是`libalgobsec.a`文件较大。确保所选MCU的Flash和RAM容量足够支持BSEC库的运行。 - 如果资源紧张,可以考虑使用BSEC库的轻量版本(Lite版本),该版本不包含自动校准功能。 - **调试和验证**: - 使用逻辑分析仪或示波器检查I2C通信是否正常。 - 检查串口输出的数据是否正确,确保BSEC库能够正确解析传感器数据。 ### 示例代码 以下是一个简单的示例代码,展示了如何在STM32 HAL库项目中集成BSEC库: ```c #include "main.h" #include "bsec.h" BSEC bsec; void SystemClock_Config(void); static void MX_GPIO_Init(void); static void MX_I2C1_Init(void); static void MX_USART1_UART_Init(void); // I2C读写函数 int8_t bsec_i2c_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *data, uint16_t len) { return HAL_I2C_Master_Transmit(&hi2c1, (dev_id << 1), &reg_addr, 1, HAL_MAX_DELAY) || HAL_I2C_Master_Receive(&hi2c1, (dev_id << 1) | 0x01, data, len, HAL_MAX_DELAY); } int8_t bsec_i2c_write(uint8_t dev_id, uint8_t reg_addr, const uint8_t *data, uint16_t len) { uint8_t tx_data[len + 1]; tx_data[0] = reg_addr; memcpy(&tx_data[1], data, len); return HAL_I2C_Master_Transmit(&hi2c1, (dev_id << 1), tx_data, len + 1, HAL_MAX_DELAY); } void bsec_delay_ms(uint32_t period) { HAL_Delay(period); } int main(void) { HAL_Init(); SystemClock_Config(); MX_GPIO_Init(); MX_I2C1_Init(); MX_USART1_UART_Init(); // 初始化BSEC库 bsec.begin(); bsec.setI2CInterface(bsec_i2c_read, bsec_i2c_write); bsec.setDelayFunction(bsec_delay_ms); // 设置传感器配置 bsec.setMode(BSEC_MODE_CONTINUOUS); while (1) { // 读取传感器数据 if (bsec.run()) { // 输出传感器数据 printf("IAQ: %.2f, Gas Resistance: %.2f Ohms, Temperature: %.2f C, Humidity: %.2f %%RH\n", bsec.iaq, bsec.gasResistance, bsec.temperature, bsec.humidity); } HAL_Delay(1000); // 每秒读取一次数据 } } ``` ###
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