野火RA6M5开发板评测 DHT11温湿度传感器 OLED显示测试学习
DHT11温湿度传感器
DHT11是一款有已校准数字信号输出的温湿度传感器。 精度湿度+-5%RH， 温度+-2℃，量程湿度20-90%RH， 温度0~50℃。
更多DHT11信息请参考：https://baike.sogou.com/v73984313.htm?fromTitle=DHT11
下图为DHT11的引脚说明图，DATA引脚为信号输入输出。
在编写DHT11驱动时，要考虑更改硬件环境的情况。我们把DHT11信号引脚相关的宏定义到 “bsp_dht11.h”文件中, 这样的话在更改或移植的时候只用改宏定义就可以。
bsp_dht11.h
#ifndef __BSP_DHT11_H
#define __BSP_DHT11_H
#include "hal_data.h"
#define Bit_RESET 0
#define Bit_SET 1
#define DHT11_LOW 0
#define DHT11_HIGH 1
#define DHT11_PORT BSP_IO_PORT_00_PIN_01
#define DHT_HIGH R_BSP_PinWrite(DHT11_PORT, BSP_IO_LEVEL_HIGH);
#define DHT_LOW R_BSP_PinWrite(DHT11_PORT, BSP_IO_LEVEL_LOW);
#define Read_Data R_BSP_PinRead(DHT11_PORT)
#define DHT11_DATA_OUT(a) if (a) \ DHT_HIGH\ else \ DHT_LOW
typedef struct
{
uint8_t humi_int; //湿度的整数部分
uint8_t humi_deci; //湿度的小数部分
uint8_t temp_int; //温度的整数部分
uint8_t temp_deci; //温度的小数部分
uint8_t check_sum; //校验和
}DHT11_Data_TypeDef;
void DHT11_Init (void);
void DHT11_Start (void);
void DHT11_DELAY_US (uint32_t delay);
void DHT11_DELAY_MS (uint32_t delay);
uint8_t Read_DHT11(DHT11_Data_TypeDef *DHT11_Data);
#endif
bsp_dht11.c
#include "bsp_dht11.h" // Device header
/* DHT11初始化函数 */
void DHT11_Init(void)
{
/* 初始化配置引脚（这里重复初始化了，可以注释掉） */
R_IOPORT_Open (&g_ioport_ctrl, g_ioport.p_cfg);
}
void DHT11_DELAY_US(uint32_t delay)
{
R_BSP_SoftwareDelay(delay, BSP_DELAY_UNITS_MICROSECONDS);
}
void DHT11_DELAY_MS(uint32_t delay)
{
R_BSP_SoftwareDelay(delay, BSP_DELAY_UNITS_MILLISECONDS);
}
//主机发送开始信号
void DHT11_Start(void)
{
DHT_HIGH; //先拉高
DHT11_DELAY_US(30);
DHT_LOW; //拉低电平至少18us
DHT11_DELAY_MS(20);
DHT_HIGH; //拉高电平20~40us
DHT11_DELAY_US(30);
}
/*
* 从DHT11读取一个字节，MSB先行
*/
static uint8_t Read_Byte(void)
{
uint8_t i, temp=0;
for(i=0;i<8;i++)
{
/*每bit以50us低电平标置开始，轮询直到从机发出 的50us 低电平 结束*/
while(Read_Data == Bit_RESET);
/*DHT11 以26~28us的高电平表示“0”，以70us高电平表示“1”，
*通过检测 x us后的电平即可区别这两个状 ，x 即下面的延时
*/
DHT11_DELAY_US(40); //延时x us 这个延时需要大于数据0持续的时间即可
if(Read_Data == Bit_SET)/* x us后仍为高电平表示数据“1” */
{
/* 等待数据1的高电平结束 */
while( Read_Data ==Bit_SET);
temp|=(uint8_t)(0x01<<(7-i)); //把第7-i位置1，MSB先行
}
else // x us后为低电平表示数据“0”
{
temp&=(uint8_t)~(0x01<<(7-i)); //把第7-i位置0，MSB先行
}
}
return temp;
}
/*
* 一次完整的数据传输为40bit，高位先出
* 8bit 湿度整数 + 8bit 湿度小数 + 8bit 温度整数 + 8bit 温度小数 + 8bit 校验和
*/
uint8_t Read_DHT11(DHT11_Data_TypeDef *DHT11_Data)
{
uint16_t count;
DHT11_Start();
DHT_HIGH; //拉高电平
/*判断从机是否有低电平响应信号 如不响应则跳出，响应则向下运行*/
if( Read_Data == Bit_RESET)
{
count=0;
/*轮询直到从机发出 的80us 低电平 响应信号结束*/
while( Read_Data ==Bit_RESET)
{
count++;
if(count>1000)
return 0;
DHT11_DELAY_US(10);
}
count=0;
/*轮询直到从机发出的 80us 高电平 标置信号结束*/
while( Read_Data==Bit_SET)
{
count++;
if(count>1000)
return 0;
DHT11_DELAY_US(10);
}
/*开始接收数据*/
DHT11_Data->humi_int= Read_Byte();
DHT11_Data->humi_deci= Read_Byte();
DHT11_Data->temp_int= Read_Byte();
DHT11_Data->temp_deci= Read_Byte();
DHT11_Data->check_sum= Read_Byte();
DHT_LOW;
DHT11_DELAY_US(55);
DHT_HIGH;
/*检查读取的数据是否正确*/
if(DHT11_Data->check_sum == DHT11_Data->humi_int + DHT11_Data->humi_deci + DHT11_Data->temp_int+ DHT11_Data->temp_deci)
return 1;
else
return 0;
}
else
{
return 0;
}
}
hal_entry.c
//--------------------------------------------------------------------------------------------------
// 函数头文件 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
//--------------------------------------------------------------------------------------------------
#include "hal_data.h"
#include "oled.h"
#include "bmp.h"
#include "bsp_debug_uart.h"
#include "bsp_led.h"
#include "bsp_dht11.h"
#include "bsp_gpt_timing.h"
#define SUCCESS 1
void Hardware_init(void);
FSP_CPP_HEADER
void R_BSP_WarmStart(bsp_warm_start_event_t event);
FSP_CPP_FOOTER
/* Callback function */
i2c_master_event_t i2c_event = I2C_MASTER_EVENT_ABORTED;
void sci_i2c_master_callback(i2c_master_callback_args_t *p_args)
{
i2c_event = I2C_MASTER_EVENT_ABORTED;
if (NULL != p_args)
{
/* capture callback event for validating the i2c transfer event*/
i2c_event = p_args->event;
}
}
fsp_err_t err = FSP_SUCCESS;
uint32_t timeout_ms = 1000;
DHT11_Data_TypeDef DHT11_Data;
uint8_t Temperature,Humidity;
extern uint8_t temp_humi_flag;
//==================================================================================================
// 函数说明: 硬件初始化
// 函数备注: Hardware_init
//--------------------------------------------------------------------------------------------------
// | - | - | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
//==================================================================================================
void Hardware_init(void)
{
Debug_UART4_Init(); // SCI4 UART 调试串口初始化
GPT0_Timing_Init();
printf("Debug-UART4-Init OK \r\n");
LED_Init();
printf("LED_Init OK \r\n");
printf("IIC-Config Start \r\n");
DHT11_Init();
printf("DHT11_Init OK \r\n");
/* Initialize the I2C module */
err = R_SCI_I2C_Open(&g_i2c5_ctrl, &g_i2c5_cfg);
/* Handle any errors. This function should be defined by the user. */
assert(FSP_SUCCESS == err);
printf("IIC-Config OK \r\n");
OLED_Init(); //初始化OLED
OLED_Clear();
printf("oled-Init OK \r\n");
}
//==================================================================================================
// 函数说明: 主函数入口
// 函数备注: hal_entry
//--------------------------------------------------------------------------------------------------
// | - | - | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
//==================================================================================================
/*******************************************************************************************************************//**
* main() is generated by the RA Configuration editor and is used to generate threads if an RTOS is used. This function
* is called by main() when no RTOS is used.
**********************************************************************************************************************/
void hal_entry(void)
{
/* TODO: add your own code here */
Hardware_init();
printf("RA6M5-Board-Init OK \r\n");
R_BSP_PinAccessEnable();
R_BSP_PinWrite(BSP_IO_PORT_00_PIN_01, BSP_IO_LEVEL_HIGH); //DHT11端口配置
while(1)
{
/*调用DHT11_Read_TempAndHumidity读取温湿度，若成功则输出该信息*/
if( Read_DHT11 ( & DHT11_Data ) == SUCCESS )
{
Temperature = DHT11_Data.temp_int;
Humidity = DHT11_Data.humi_int;
}
OLED_ShowCHinese(0,0,0);//瑞
OLED_ShowCHinese(16,0,1);//萨
OLED_ShowCHinese(32,0,5);//电
OLED_ShowCHinese(48,0,6);//子
OLED_ShowString(60,0,"Renesas",16);
OLED_ShowNum(0,2,2023,4,16);//显示ASCII字符的码值
OLED_ShowCHinese(32,2,2);//中文字->年
OLED_ShowNum(48,2,5,2,16);//显示ASCII字符的码值
OLED_ShowCHinese(64,2,3);//中文字->月
OLED_ShowNum(80,2,26,2,16);//显示ASCII字符的码值
OLED_ShowCHinese(96,2,4);//中文字->日
OLED_ShowCHinese(0,4,7); //中文字->温
OLED_ShowCHinese(16,4,9); //中文字->度
OLED_ShowNum(32,4,Temperature,2,16);
OLED_ShowCHinese(64,4,8); //中文字->湿
OLED_ShowCHinese(80,4,9); //中文字->度
OLED_ShowNum(96,4,Humidity,2,16);
OLED_ShowString(0,6,"RA6M5-Embedfire",16);
}
#if BSP_TZ_SECURE_BUILD
/* Enter non-secure code */
R_BSP_NonSecureEnter();
#endif
}
/*******************************************************************************************************************//**
* This function is called at various points during the startup process. This implementation uses the event that is
* called right before main() to set up the pins.
*
* @param[in] event Where at in the start up process the code is currently at
**********************************************************************************************************************/
void R_BSP_WarmStart(bsp_warm_start_event_t event)
{
if (BSP_WARM_START_RESET == event)
{
#if BSP_FEATURE_FLASH_LP_VERSION != 0
/* Enable reading from data flash. */
R_FACI_LP->DFLCTL = 1U;
/* Would normally have to wait tDSTOP(6us) for data flash recovery. Placing the enable here, before clock and
* C runtime initialization, should negate the need for a delay since the initialization will typically take more than 6us. */
#endif
}
if (BSP_WARM_START_POST_C == event)
{
/* C runtime environment and system clocks are setup. */
/* Configure pins. */
R_IOPORT_Open (&g_ioport_ctrl, g_ioport.p_cfg);
}
}
#if BSP_TZ_SECURE_BUILD
BSP_CMSE_NONSECURE_ENTRY void template_nonsecure_callable ();
/* Trustzone Secure Projects require at least one nonsecure callable function in order to build (Remove this if it is not required to build). */
BSP_CMSE_NONSECURE_ENTRY void template_nonsecure_callable ()
{
}
#endif
测试效果
