在进行DAC的学习中，发现RT-Thread中没有该外设的驱动，因此需要自己进行相关配置
1.配置RT-Thread Setting中的DAC组件
2.在HAL库中完成DAC的配置(HAL库起到时钟的作用)
不懂HAL库配置的最好学一下HAL库的编程思想
3.在board.h中添加宏定义
我的RT-Thread中，没有DAC的宏定义，因此我就在末尾直接添加了一个：#define BSP_USING_DAC1
4.打开stm32f7xx_hal_config.h文件，接触DAC的注释
5.DAC驱动代码移植
<1>在/drivers/include/config文件夹下新建dac_config.h
#ifndef __DAC_CONFIG_H__
#define __DAC_CONFIG_H__#include <rtthread.h>#ifdef __cplusplus
extern "C" {
#endif#ifdef BSP_USING_DAC1
#ifndef DAC1_CONFIG
#define DAC1_CONFIG \{ \.Instance = DAC1, \}
#endif /* DAC2_CONFIG */
#endif /* BSP_USING_DAC2 */#ifdef BSP_USING_DAC2
#ifndef DAC2_CONFIG
#define DAC2_CONFIG \{ \.Instance = DAC2, \}
#endif /* DAC2_CONFIG */
#endif /* BSP_USING_DAC2 */#ifdef __cplusplus
}
#endif#endif /* __DAC_CONFIG_H__ */<2>修改/drivers/include/drv_config.h
在STM32F1系列下增加#include “config/dac_config.h”，代码如下
#if defined(SOC_SERIES_STM32F0)
#include "config/dma_config.h"
#include "config/uart_config.h"
#include "config/spi_config.h"
#include "config/tim_config.h"
#include "config/pwm_config.h"
#include "config/adc_config.h"
#elif defined(SOC_SERIES_STM32F1)
#include "config/dac_config.h" //新增
#include "config/dma_config.h"
#include "config/uart_config.h"
#include "config/spi_config.h"
#include "config/adc_config.h"
#include "config/tim_config.h"
#include "config/sdio_config.h"
#include "config/pwm_config.h"
#include "config/usbd_config.h"
#include "config/pulse_encoder_config.h"<3>在drivers文件夹下新建drv_dac.c
/** Copyright (c) 2006-2021, RT-Thread Development Team** SPDX-License-Identifier: Apache-2.0** Change Logs:* Date Author Notes* 2020-06-18 thread-liu the first version* 2020-10-09 thread-liu Porting for stm32h7xx*/#include <board.h>
#include<rtthread.h>
#include<rtdevice.h>#if defined(BSP_USING_DAC1) || defined(BSP_USING_DAC2)
#include "drv_config.h"//#define DRV_DEBUG
#define LOG_TAG "drv.dac"
#include <drv_log.h>static DAC_HandleTypeDef dac_config[] =
{
#ifdef BSP_USING_DAC1DAC1_CONFIG,
#endif#ifdef BSP_USING_DAC2DAC2_CONFIG,
#endif
};struct stm32_dac
{DAC_HandleTypeDef DAC_Handler;struct rt_dac_device stm32_dac_device;
};static struct stm32_dac stm32_dac_obj[sizeof(dac_config) / sizeof(dac_config[0])];static rt_uint32_t stm32_dac_get_channel(rt_uint32_t channel)
{rt_uint32_t stm32_channel = 0;switch (channel){case 1:stm32_channel = DAC_CHANNEL_1;break;case 2:stm32_channel = DAC_CHANNEL_2;break;default:RT_ASSERT(0);break;}return stm32_channel;
}static rt_err_t stm32_dac_enabled(struct rt_dac_device *device, rt_uint32_t channel)
{uint32_t dac_channel;DAC_HandleTypeDef *stm32_dac_handler;RT_ASSERT(device != RT_NULL);stm32_dac_handler = device->parent.user_data;#if 1if ((channel <= 2) && (channel > 0)){/* set stm32 dac channel */dac_channel = stm32_dac_get_channel(channel);}else{LOG_E("dac channel must be 1 or 2.");return -RT_ERROR;}HAL_DAC_Start(stm32_dac_handler, dac_channel);
#endifreturn RT_EOK;
}static rt_err_t stm32_dac_disabled(struct rt_dac_device *device, rt_uint32_t channel)
{uint32_t dac_channel;DAC_HandleTypeDef *stm32_dac_handler;RT_ASSERT(device != RT_NULL);stm32_dac_handler = device->parent.user_data;#if 1if ((channel <= 2) && (channel > 0)){/* set stm32 dac channel */dac_channel = stm32_dac_get_channel(channel);}else{LOG_E("dac channel must be 1 or 2.");return -RT_ERROR;}HAL_DAC_Stop(stm32_dac_handler, dac_channel);
#endifreturn RT_EOK;
}static rt_err_t stm32_set_dac_value(struct rt_dac_device *device, rt_uint32_t channel, rt_uint32_t *value)
{uint32_t dac_channel;DAC_ChannelConfTypeDef DAC_ChanConf;DAC_HandleTypeDef *stm32_dac_handler;RT_ASSERT(device != RT_NULL);RT_ASSERT(value != RT_NULL);stm32_dac_handler = device->parent.user_data;rt_memset(&DAC_ChanConf, 0, sizeof(DAC_ChanConf));#if 1if ((channel <= 2) && (channel > 0)){/* set stm32 dac channel */dac_channel = stm32_dac_get_channel(channel);}else{LOG_E("dac channel must be 1 or 2.");return -RT_ERROR;}
#endif#if 1DAC_ChanConf.DAC_Trigger = DAC_TRIGGER_NONE;DAC_ChanConf.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
#endif/* config dac out channel*/if (HAL_DAC_ConfigChannel(stm32_dac_handler, &DAC_ChanConf, dac_channel) != HAL_OK){LOG_D("Config dac out channel Error!\n");return -RT_ERROR;}/* set dac channel out value*/if (HAL_DAC_SetValue(stm32_dac_handler, dac_channel, DAC_ALIGN_12B_R, *value) != HAL_OK){LOG_D("Setting dac channel out value Error!\n");return -RT_ERROR;}/* start dac */if (HAL_DAC_Start(stm32_dac_handler, dac_channel) != HAL_OK){LOG_D("Start dac Error!\n");return -RT_ERROR;}return RT_EOK;
}static const struct rt_dac_ops stm_dac_ops =
{.disabled = stm32_dac_disabled,.enabled = stm32_dac_enabled,.convert = stm32_set_dac_value,
};static int stm32_dac_init(void)
{int result = RT_EOK;/* save dac name */char name_buf[5] = {'d', 'a', 'c', '0', 0};int i = 0;for (i = 0; i < sizeof(dac_config) / sizeof(dac_config[0]); i++){/* dac init */name_buf[3] = '0';stm32_dac_obj[i].DAC_Handler = dac_config[i];
#if defined(DAC1)if (stm32_dac_obj[i].DAC_Handler.Instance == DAC1){name_buf[3] = '1';}
#endif
#if defined(DAC2)if (stm32_dac_obj[i].dac_Handler.Instance == DAC2){name_buf[3] = '2';}
#endifif (HAL_DAC_Init(&stm32_dac_obj[i].DAC_Handler) != HAL_OK){LOG_E("%s init failed", name_buf);result = -RT_ERROR;}else{/* register dac device */if (rt_hw_dac_register(&stm32_dac_obj[i].stm32_dac_device, name_buf, &stm_dac_ops, &stm32_dac_obj[i].DAC_Handler) == RT_EOK){LOG_D("%s init success", name_buf);}else{LOG_E("%s register failed", name_buf);result = -RT_ERROR;}}}return result;
}
INIT_DEVICE_EXPORT(stm32_dac_init);#endif /* BSP_USING_DAC */
运行代码
#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>#define DAC_DEV_NAME "dac1" /* DAC 设备名称 */
#define DAC_DEV_CHANNEL 1 /* DAC 通道 */
rt_dac_device_t dac_dev;
#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 */void dac_set_vol(rt_uint32_t vol)//1000->1V
{rt_uint32_t value;double temp=vol;temp=temp/1000;temp=temp*4095/3.3;value=temp;rt_dac_write(dac_dev, DAC_DEV_CHANNEL, vol);
}int main(void)
{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;}//使能设备ret = rt_dac_enable(dac_dev, DAC_DEV_CHANNEL);//设置输出值dac_set_vol(300);//关闭通道 这里的disable也关闭了，貌似用不了，是不是可以用HAL库的呢？//ret = rt_dac_disable(dac_dev, DAC_DEV_CHANNEL);return ret;
}最后
RT-Thread中存在着部分外设没有驱动程序需要我们自己去移植，或者使用HAL库的编程思想去实现
