RT-Thread Studio学习（十三）DAC

一、简介
二、新建RT-Thread项目并使用外部时钟
三、启用DAC
四、测试
五、总结

一、简介

本文将基于STM32F407VET芯片介绍如何在RT-Thread Studio开发环境下使用DAC设备。硬件及开发环境如下：

OS WIN10
STM32F407VET6
STM32CubeMX v6.10.0
STM32Cube MCU Package for STM32F4 Series v1.28.0
RT-Thread Studio v2.2.7
RT-Thread Source Code v5.0.2
STM32F4 chip support packages v0.2.3

二、新建RT-Thread项目并使用外部时钟

打开RT-Thread Studio软件新建基于芯片的项目，并使用外部时钟系统，具体参见《RT-Thread Studio学习（一）使用外部时钟系统》。

三、启用DAC

打开DAC驱动框架
在RT-Thread Setting 中借助图形化配置工具打开软件DAC的驱动框架，如下图所示
定义DAC相关的宏
在board.h文件末尾添加：

/*-------------------------- DAC CONFIG BEGIN --------------------------*//** if you want to use dac you can use the following instructions.** STEP 1, open dac driver framework support in the RT-Thread Settings file** STEP 2, define macro related to the dac*                 such as     #define BSP_USING_DAC1** STEP 3, copy your dac init function from stm32xxxx_hal_msp.c generated by stm32cubemx to the end of board.c file*                 such as     void HAL_DAC_MspInit(DAC_HandleTypeDef* dacHandle)** STEP 4, modify your stm32xxxx_hal_config.h file to support dac peripherals. define macro related to the peripherals*                 such as     #define HAL_DAC_MODULE_ENABLED**/#define BSP_USING_DAC1/*-------------------------- DAC CONFIG END --------------------------*/

复制DAC初始化函数
双击RT-Thread Studio工程中的cubemx.ioc文件，使能DAC1和DAC2，具体如下图：
从使能DAC后再重新生成STM32CubeMX代码，将.\cubemx\Src\dac.c中的函数HAL_DAC_MspInit(DAC_HandleTypeDef* dacHandle)复制到board.c的末尾。

void HAL_DAC_MspInit(DAC_HandleTypeDef* dacHandle)
{GPIO_InitTypeDef GPIO_InitStruct = {0};if(dacHandle->Instance==DAC){/* USER CODE BEGIN DAC_MspInit 0 *//* USER CODE END DAC_MspInit 0 *//* DAC clock enable */__HAL_RCC_DAC_CLK_ENABLE();__HAL_RCC_GPIOA_CLK_ENABLE();/**DAC GPIO ConfigurationPA4     ------> DAC_OUT1PA5     ------> DAC_OUT2*/GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5;GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;GPIO_InitStruct.Pull = GPIO_NOPULL;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);/* USER CODE BEGIN DAC_MspInit 1 *//* USER CODE END DAC_MspInit 1 */}
}

定义.\cubemx\Inc\stm32f4xx_hal_conf.h中的相关宏

#define HAL_DAC_MODULE_ENABLED

四、测试

修改main.c的代码为：

/** Copyright (c) 2006-2024, RT-Thread Development Team** SPDX-License-Identifier: Apache-2.0** Change Logs:* Date           Author       Notes* 2024-01-15     RT-Thread    first version*/#include <rtthread.h>
#include "stm32f4xx.h"
#include <rtdevice.h>#define DBG_TAG "main"
#define DBG_LVL DBG_LOG
#include <rtdbg.h>// PA4     ------> DAC_OUT1
// PA5     ------> DAC_OUT2
DAC_HandleTypeDef hdac;#define DAC_DEV_NAME        "dac1"  /* DAC 设备名称 */
#define DAC_DEV_CHANNEL     1       /* DAC 通道 */
#define REFER_VOLTAGE       330         /* 参考电压 3.3V,数据精度乘以100保留2位小数*/
#define CONVERT_BITS        (1 << 12)   /* 转换位数为12位 */// 设置dac的使用命令 dac_set dac1 1 200
// 第一个参数为命令，第二个参数为 dac 设备名称，第 3 个参数为 dac 通道，
// 第 4 个参数为 dac 输出数值
static int dac_set(int argc, char *argv[])
{if(argc!=4){rt_kprintf("Usage:    dac_set <device name> <channel> <value>\n");rt_kprintf("Example:  dac_set dac1 1 1000\n");return RT_ERROR;}rt_dac_device_t dac_dev;rt_uint32_t value, vol, channel;rt_err_t ret = RT_EOK;char dacdevname[RT_NAME_MAX];rt_strncpy(dacdevname, argv[1], RT_NAME_MAX);channel = atoi(argv[2]);  // DAC channelvalue = atoi(argv[3]);/* 查找设备 */dac_dev = (rt_dac_device_t)rt_device_find(dacdevname);if (dac_dev == RT_NULL){rt_kprintf("dac sample run failed! can't find %s device!\n", dacdevname);return RT_ERROR;}/* 打开通道 */ret = rt_dac_enable(dac_dev, channel);/* 设置输出值 */rt_dac_write(dac_dev, channel, value);rt_kprintf("the value is :%d \n", value);/* 转换为对应电压值 */vol = value * REFER_VOLTAGE / CONVERT_BITS;rt_kprintf("the voltage is :%d.%02d \n", vol / 100, vol % 100);/* 延时查看效果，关闭通道后无输出 */
//    rt_thread_mdelay(500);/* 关闭通道 */
//    ret = rt_dac_disable(dac_dev, channel);return ret;
}static int dac1_vol_sample()
{rt_dac_device_t dac_dev;rt_uint32_t value, vol;rt_err_t ret = RT_EOK;/* 查找设备 */dac_dev = (rt_dac_device_t)rt_device_find(DAC_DEV_NAME);if (dac_dev == RT_NULL){rt_kprintf("dac sample run failed! can't find %s device!\n", DAC_DEV_NAME);return RT_ERROR;}/* 打开通道 */ret = rt_dac_enable(dac_dev, DAC_DEV_CHANNEL);/* 设置输出值 */value=1000;rt_dac_write(dac_dev, DAC_DEV_CHANNEL, value);rt_kprintf("the value is :%d \n", value);/* 转换为对应电压值 */vol = value * REFER_VOLTAGE / CONVERT_BITS;rt_kprintf("the voltage is :%d.%02d \n", vol / 100, vol % 100);/* 延时查看效果，关闭通道后无输出 */// rt_thread_mdelay(500);/* 关闭通道 */// ret = rt_dac_disable(dac_dev, DAC_DEV_CHANNEL);return ret;
}int main(void)
{int count = 1;LOG_D("Hello RT-Thread! 2024.1.17");LOG_D("System CLock information");LOG_D("SYSCLK_Frequency = %d", HAL_RCC_GetSysClockFreq());LOG_D("HCLK_Frequency   = %d", HAL_RCC_GetHCLKFreq());LOG_D("PCLK1_Frequency  = %d", HAL_RCC_GetPCLK1Freq());LOG_D("PCLK2_Frequency  = %d", HAL_RCC_GetPCLK2Freq());LOG_D("SysTick->LOAD    = %d", SysTick->LOAD);LOG_D("Current tick     = %d", rt_tick_get());dac1_vol_sample();while (count++){LOG_D("Hello RT-Thread! %d", rt_tick_get());rt_thread_mdelay(60000);}return RT_EOK;
}/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(dac_set, set dac voltage. Useage: dac_set adc1 1 200);