项目需求
使用温湿度传感器模块(DHT11)获取温度及湿度,并将值显示在LCD1602上,同时通过蓝牙模块透传到手机。
项目框图

一、LCD1602实战
硬件接线
D0 ~ D7 – A0 ~ A7
RS – B1
RW – B2
EN – B10
V0 – GND(正视看不到显示结果,需要侧着看。否则需要接可调电阻)
//背光灯
BLA – 5V
BLK – GDN
引脚封装
RS、RW、EN三根信号线经常需要进行拉高/拉低操作,可以进行封装
#define RS_GPIO_Port GPIOB
#define RW_GPIO_Port GPIOB
#define EN_GPIO_Port GPIOB
#define RS_Pin GPIO_PIN_1
#define RW_Pin GPIO_PIN_2
#define EN_Pin GPIO_PIN_10
#define RS_HIGH HAL_GPIO_WritePin(RS_GPIO_Port, RS_Pin, GPIO_PIN_SET)
#define RS_LOW HAL_GPIO_WritePin(RS_GPIO_Port, RS_Pin, GPIO_PIN_RESET)
#define RW_HIGH HAL_GPIO_WritePin(RW_GPIO_Port, RW_Pin, GPIO_PIN_SET)
#define RW_LOW HAL_GPIO_WritePin(RW_GPIO_Port, RW_Pin, GPIO_PIN_RESET)
#define EN_HIGH HAL_GPIO_WritePin(EN_GPIO_Port, EN_Pin, GPIO_PIN_SET)
#define EN_LOW HAL_GPIO_WritePin(EN_GPIO_Port, EN_Pin, GPIO_PIN_RESET)
如何将一个字节的数据按位一次性发送到GPIOA的8个管脚?
GPIOA->ODR = cmd;
具体代码如下:
void Write_Cmd_Func(char cmd)
{
RS_LOW;
RW_LOW;
EN_LOW;
GPIOA->ODR = cmd;
HAL_Delay(5);
EN_HIGH;
HAL_Delay(5);
EN_LOW;
}
void Write_Data_Func(char dataShow)
{
RS_HIGH;
RW_LOW;
EN_LOW;
GPIOA->ODR = dataShow;
HAL_Delay(5);
EN_HIGH;
HAL_Delay(5);
EN_LOW;
}
void LCD1602_INIT()
{
//(1)延时 15ms
HAL_Delay(15);
//(2)写指令 38H(不检测忙信号)
Write_Cmd_Func(0x38);
//(3)延时 5ms
HAL_Delay(5);
//(4)以后每次写指令,读/写数据操作均需要检测忙信号
//(5)写指令 38H:显示模式设置
Write_Cmd_Func(0x38);
//(6)写指令 08H:显示关闭
Write_Cmd_Func(0x08);
//(7)写指令 01H:显示清屏
Write_Cmd_Func(0x01);
//(8)写指令 06H:显示光标移动设置
Write_Cmd_Func(0x06);
//(9)写指令 0CH:显示开及光标设置
Write_Cmd_Func(0x0c);
}
void LCD1602_showLine(char row, char col, char *string)
{
switch(row){
case 1:
Write_Cmd_Func(0x80 + col);
while(*string){
Write_Data_Func(*string);
string++;
}
break;
case 2:
Write_Cmd_Func(0x80 + 0x40 + col);
while(*string){
Write_Data_Func(*string);
string++;
}
break;
}
}
// main.c
LCD1602_INIT();
LCD1602_showLine(1, 5, "NO.2");
LCD1602_showLine(2, 0, "hello handsome");

二、 DHT11介绍及实战
硬件接线
DAT – PB7
注意:
PB7既作为输入,也作为输出,则不能直接在CubeMX里配置,需要自己写代码
引脚封装
#define DHT_HIGHT HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_SET)
#define DHT_LOW HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_RESET)
#define DHT_VALUE HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7)
具体代码如下
#define DHT_HIGHT HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_SET)
#define DHT_LOW HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_RESET)
#define DHT_VALUE HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7)
uint8_t datas[5];
void delay_us(uint16_t cnt)
{
uint8_t i;
while(cnt)
{
for (i = 0; i < 10; i++)
{
}
cnt--;
}
}
// 初始化GPIO
void DHT_GPIO_Init(uint32_t Mode)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
__HAL_RCC_GPIOB_CLK_ENABLE();
GPIO_InitStruct.Pin = GPIO_PIN_7;
GPIO_InitStruct.Mode = Mode;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}
void DHT11_Start()
{
DHT_GPIO_Init(GPIO_MODE_OUTPUT_PP);
DHT_HIGHT;
DHT_LOW;
HAL_Delay(30);
DHT_HIGHT;
DHT_GPIO_Init(GPIO_MODE_INPUT);
while(DHT_VALUE);
while(!DHT_VALUE);
while(DHT_VALUE);
}
void Read_Data_From_DHT()
{
int i;//轮
int j;//每一轮读多少次
char tmp;
char flag;
DHT11_Start();
DHT_GPIO_Init(GPIO_MODE_INPUT);
for(i= 0;i < 5;i++){
//卡g点:while(!dht) 有效数据都是高电平,持续时间不一样,50us读,低电平0 高电平
for(j=0;j<8;j++){
while(!DHT_VALUE);//等待卡g点
delay_us(40);
if(DHT_VALUE == 1){
flag = 1;
while(DHT_VALUE);
}else{
flag = 0;
}
tmp = tmp << 1;
tmp |= flag;
}
datas[i] = tmp;
}
}
int fputc(int ch, FILE *f)
{
unsigned char temp[1]={ch};
HAL_UART_Transmit(&huart1,temp,1,0xffff);
return ch;
}
// main.c
printf("dzz hansome\r\n");
HAL_Delay(2000);
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
Read_Data_From_DHT();
printf("Temp: %d.%d ", datas[2], datas[3]);
printf("Humi: %d.%d\r\n", datas[0], datas[1]);
HAL_Delay(2000);
}

三、整合LCD1602和 DHT11

- 在项目core > src文件夹下新建 dht11.c 、lcd1602.c

- 在core > lnc 文件下新建 dht11.h 、lcd1602.h

- 把新建的 .c 文件加进来



具体代码如下:
lcd1602.c
#include "lcd1602.h"
#include "gpio.h"
#define RS_GPIO_Port GPIOB
#define RW_GPIO_Port GPIOB
#define EN_GPIO_Port GPIOB
#define RS_Pin GPIO_PIN_1
#define RW_Pin GPIO_PIN_2
#define EN_Pin GPIO_PIN_10
#define RS_HIGH HAL_GPIO_WritePin(RS_GPIO_Port, RS_Pin, GPIO_PIN_SET)
#define RS_LOW HAL_GPIO_WritePin(RS_GPIO_Port, RS_Pin, GPIO_PIN_RESET)
#define RW_HIGH HAL_GPIO_WritePin(RW_GPIO_Port, RW_Pin, GPIO_PIN_SET)
#define RW_LOW HAL_GPIO_WritePin(RW_GPIO_Port, RW_Pin, GPIO_PIN_RESET)
#define EN_HIGH HAL_GPIO_WritePin(EN_GPIO_Port, EN_Pin, GPIO_PIN_SET)
#define EN_LOW HAL_GPIO_WritePin(EN_GPIO_Port, EN_Pin, GPIO_PIN_RESET)
void Write_Cmd_Func(char cmd)
{
RS_LOW;
RW_LOW;
EN_LOW;
GPIOA->ODR = cmd;
HAL_Delay(5);
EN_HIGH;
HAL_Delay(5);
EN_LOW;
}
void Write_Data_Func(char dataShow)
{
RS_HIGH;
RW_LOW;
EN_LOW;
GPIOA->ODR = dataShow;
HAL_Delay(5);
EN_HIGH;
HAL_Delay(5);
EN_LOW;
}
void LCD1602_INIT(void)
{
//(1)延时 15ms
HAL_Delay(15);
//(2)写指令 38H(不检测忙信号)
Write_Cmd_Func(0x38);
//(3)延时 5ms
HAL_Delay(5);
//(4)以后每次写指令,读/写数据操作均需要检测忙信号
//(5)写指令 38H:显示模式设置
Write_Cmd_Func(0x38);
//(6)写指令 08H:显示关闭
Write_Cmd_Func(0x08);
//(7)写指令 01H:显示清屏
Write_Cmd_Func(0x01);
//(8)写指令 06H:显示光标移动设置
Write_Cmd_Func(0x06);
//(9)写指令 0CH:显示开及光标设置
Write_Cmd_Func(0x0c);
}
void LCD1602_showLine(char row, char col, char *string)
{
switch(row){
case 1:
Write_Cmd_Func(0x80 + col);
while(*string){
Write_Data_Func(*string);
string++;
}
break;
case 2:
Write_Cmd_Func(0x80 + 0x40 + col);
while(*string){
Write_Data_Func(*string);
string++;
}
break;
}
}
lcd1602.h
#ifndef __LCD1602_H__
#define __LCD1602_H__
void LCD1602_INIT(void);
void LCD1602_showLine(char row, char col, char *string);
#endif
dht11.c
#include "dht11.h"
#include "gpio.h"
#include "usart.h"
#include <stdio.h>
#define DHT_HIGHT HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_SET)
#define DHT_LOW HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_RESET)
#define DHT_VALUE HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7)
uint8_t datas[5];
void delay_us(uint16_t cnt)
{
uint8_t i;
while(cnt)
{
for (i = 0; i < 10; i++)
{
}
cnt--;
}
}
// 初始化GPIO
void DHT_GPIO_Init(uint32_t Mode)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
__HAL_RCC_GPIOB_CLK_ENABLE();
GPIO_InitStruct.Pin = GPIO_PIN_7;
GPIO_InitStruct.Mode = Mode;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}
void DHT11_Start()
{
DHT_GPIO_Init(GPIO_MODE_OUTPUT_PP);
DHT_HIGHT;
DHT_LOW;
HAL_Delay(30);
DHT_HIGHT;
DHT_GPIO_Init(GPIO_MODE_INPUT);
while(DHT_VALUE);
while(!DHT_VALUE);
while(DHT_VALUE);
}
void Read_Data_From_DHT(void)
{
int i;//轮
int j;//每一轮读多少次
char tmp;
char flag;
DHT11_Start();
DHT_GPIO_Init(GPIO_MODE_INPUT);
for(i= 0;i < 5;i++){
//卡g点:while(!dht) 有效数据都是高电平,持续时间不一样,50us读,低电平0 高电平
for(j=0;j<8;j++){
while(!DHT_VALUE);//等待卡g点
delay_us(40);
if(DHT_VALUE == 1){
flag = 1;
while(DHT_VALUE);
}else{
flag = 0;
}
tmp = tmp << 1;
tmp |= flag;
}
datas[i] = tmp;
}
}
dht11.h
#ifndef __DHT11_H__
#define __DHT11_H__
void Read_Data_From_DHT(void);
#endif
uart.c
#include "stdio.h"
int fputc(int ch, FILE *f)
{
unsigned char temp[1]={ch};
HAL_UART_Transmit(&huart1,temp,1,0xffff);
return ch;
}
最后在main.c 引入并测试
/* USER CODE BEGIN Includes */
#include "lcd1602.h"
#include "stdio.h"
#include "dht11.h"
/* USER CODE END Includes */
/* USER CODE BEGIN PV */
extern uint8_t datas[5];
/* USER CODE END PV */
int main(void)
{
/* USER CODE BEGIN 2 */
printf("hello world\r\n");
LCD1602_INIT();
LCD1602_showLine(1, 5, "NO.2");
LCD1602_showLine(2, 0, "hello handsome");
HAL_Delay(2000);
/* USER CODE END 2 */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
Read_Data_From_DHT();
printf("Temp: %d.%d ", datas[2], datas[3]);
printf("Humi: %d.%d\r\n", datas[0], datas[1]);
HAL_Delay(2000);
}
/* USER CODE END 3 */
}

整合LCD1602和 DHT11 ok!
四、把温湿度显示到lcd1602
#include "string.h"
char message[16];
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
Read_Data_From_DHT();
memset(message, 0, sizeof(message));
sprintf(message, "Temp: %d.%d", datas[2], datas[3]);
LCD1602_showLine(1, 0, message);
memset(message, 0, sizeof(message));
sprintf(message, "Humi: %d.%d", datas[0], datas[1]);
LCD1602_showLine(2, 0, message);
HAL_Delay(2000);
}

该项目使用STM32微控制器,通过DHT11传感器获取环境温湿度,数据显示在LCD1602屏幕上,并通过蓝牙模块将数据传输到手机。代码中详细实现了GPIO控制、LCD1602初始化和DHT11数据读取。
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