STM32与DS18B20数字温度传感器寄生供电方式的新方案与1-wire总线程序设计
DS18B20是常用的一种数字温度传感器，通过1-wire总线实现传感器内部寄存器的访问。传感器有两种供电方式，一种是恒定供电，也就是VDD端一直供电，是大部分参考设计采用的方式，然而此种方式会对芯片产生一定的通流加热过程，所以在环境温度不变时，测量温度在缓慢上升，直到升到一个工作电流发热和环境散热的平衡点，这个测量温度可能比实际的环境温度高几度，因此存在测量温差。这种方式的官方连接关系如下图所示：
另一种是寄生供电，VDD接到地，通过Open-drain方式的数据端DQ的上拉通道对内部电容的预充电提供基本访问的供电，然后芯片内部做温度转换的过程需要抽取更多的电流，因此需要在发布转换命令后10us内将DQ拉到强供电端以提供转换电流，此种方式的官方连接如下图所示：
可见寄生供电的方式需要MCU提供一个GPIO控制增强电流供电端的MOS管或三级管。在温度转换过程前打开供电，在温度转换后关闭供电。由于VDD没有保持供电，因此寄生供电模式没有造成额外温升，测量温度的稳定性更高。
DS18B20寄生供电方式新方案
温度转换过程所要抽拉的额定电流规格为1.5mA：
1.5mA在MCU的GPIO电流安全输出范围内，这里提出新的寄生供电方式方案，去除了MOS管或三级管的使用，简化了电路连接，并成功验证。具体的方案如下：
方案的改进是直接将DS18B20 VDD接到STM32的一个GPIO, 在基本访问过程GPIO输出0即DS18B20 VDD接地，在转换过程前GPIO输出1即提供电压给DS18B20 VDD, 从而在转换过程中DS18B20处于VDD供电状态，转换完成后GPIO再输出0即DS18B20 VDD接地，继续基本访问的读操作。本方案的寄生供电特点是从DS18B20 VDD提供转换过程电流，原方案是从DS18B20 DQ提供转换过程电流。
STM32工程配置
这里以STM32G030F6P6芯片及STM32CUBEIDE开发工具实现DS18B20寄生供电方式的代码案例。
首先建立工程并配置时钟系统：
然后配置管脚A0为Open Drain输出（连接DS18B20 DQ），配置A1为Push Pull输出（连接DS18B20 VDD）。
并配置USART2作为温度检测结果输出接口，全部采用默认参数即可。
保存并生成初始工程代码：
STM32访问DS18B20工程代码
模拟1-wire协议要用到微秒级延时函数，这里采用的微秒延时函数： STM32 HAL us delay（微秒延时）的指令延时实现方式及优化 。
在进行DS18B20前，要先读取64位的ROM ID, 然后对此读到的ROM ID进行校验，以验证1-wire的访问是否正确，然后再进行后续的温度读取操作。ROM ID由1个字节的家族码，6个字节的产品码和1个字节的CRC-8校验码组成。因此校验方式是将家族码和产品码总共7个字节进行CRC-8计算得到计算码，然后将计算码和最后一个字节的校验码进行比较，相同则证明1-wire访问正确。这里采用的CRC-8计算函数： C语言标准CRC-8校验函数 。
STM32模拟1-wire访问DS18B20的函数定义为：
#define DQ_0 HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_RESET);
#define DQ_1 HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_SET);
#define DQ_IS_LOW HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0)==0?1:0
#define CONVERSION_VOLTAGE 1 //0: DS18B20 constant VCC mode. 1: DS18B20 short term VCC mode only supplying for conversion process.
#define CV_ON HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_SET) //supply power to DS18B20 VCC
#define CV_OFF HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET) //not supply power to DS18B20 VCC
#define GPIO_EXEC_DELAY_us 8
uint8_t DS18B20_Reset(void) //Bus reset timing in page 15 of spec
{
__disable_irq();
DQ_1;
PY_Delay_us_t(10); //Pull high, ready to send reset request
DQ_0;
PY_Delay_us_t(520); //Minimum 480us
DQ_1;
PY_Delay_us_t(15+55-GPIO_EXEC_DELAY_us);
if (DQ_IS_LOW)
{
PY_Delay_us_t(420);
__enable_irq();
return 1;
}
else
{
PY_Delay_us_t(420);
__enable_irq();
return 0;
}
}
void DS18B20_WriteByte(uint8_t val)
{
__disable_irq();
for (uint8_t i = 0; i < 8; i++)
{
DQ_0;
PY_Delay_us_t(15-GPIO_EXEC_DELAY_us);
if (val & 0x01)
{
DQ_1;
}
else
{
DQ_0;
}
PY_Delay_us_t(100);
DQ_1;
PY_Delay_us_t(4);
val >>= 1;
}
__enable_irq();
}
uint8_t DS18B20_ReadByte(void)
{
uint8_t read = 0;
__disable_irq();
for (uint8_t i = 0; i < 8; i++)
{
read >>= 1;
DQ_0;
PY_Delay_us_t(2);
DQ_1;
PY_Delay_us_t(12-GPIO_EXEC_DELAY_us);
if (!DQ_IS_LOW) read |= 0x80;
PY_Delay_us_t(50);
}
PY_Delay_us_t(60);
__enable_irq();
return read;
}
uint16_t DS18B20_ReadTempReg(void)
{
uint8_t tempL, tempH;
if(CONVERSION_VOLTAGE) CV_ON;
DS18B20_Reset();
DS18B20_WriteByte(0xcc);
DS18B20_WriteByte(0x44);
PY_Delay_us_t(2);
DQ_0;
PY_Delay_us_t(2);
DQ_1;
PY_Delay_us_t(800000); //conversion delay
if(CONVERSION_VOLTAGE) CV_OFF;
DS18B20_Reset();
DS18B20_WriteByte(0xcc);
DS18B20_WriteByte(0xbe);
tempL = DS18B20_ReadByte();
PY_Delay_us_t(60);
tempH = DS18B20_ReadByte();
DS18B20_Reset();
if (tempH>7) return 0;
else {return ((((uint16_t)tempH) << 8) | (uint16_t)tempL);}
}
uint64_t DS18B20_ReadID()
{
uint64_t ROMID=0;
uint8_t RD[8];
if (DS18B20_Reset() == 0)
{
return 0;
}
DS18B20_WriteByte(0x33);
for (uint8_t i = 0; i < 8; i++)
{
ROMID <<=8;
ROMID |= DS18B20_ReadByte();
}
DS18B20_Reset();
for(int8_t i=7;i>=0;i--)
{
RD[7-i] = (ROMID>>(i*8));
}
if (PY_CRC_8(RD, 7)==RD[7]) ROMID= *(uint64_t *)RD;
else ROMID = 0xFFFFFFFFFFFFFFFF;
return ROMID;
}
uint16_t DS18B20_ReadTempByID(uint64_t ROMID)
{
uint8_t tempL, tempH;
uint8_t i;
uint64_t ROMID_t = ROMID;
if(CONVERSION_VOLTAGE) CV_ON;
DS18B20_Reset();
DS18B20_WriteByte(0x55);
for (i = 0; i < 8; i++)
{
DS18B20_WriteByte((uint8_t)ROMID_t);
ROMID_t>>=8;
}
DS18B20_WriteByte(0x44);
PY_Delay_us_t(2);
DQ_0;
PY_Delay_us_t(2);
DQ_1;
PY_Delay_us_t(800000); //conversion delay
if(CONVERSION_VOLTAGE) CV_OFF;
ROMID_t = ROMID;
DS18B20_Reset();
DS18B20_WriteByte(0x55);
for (i = 0; i < 8; i++)
{
DS18B20_WriteByte((uint8_t)ROMID_t);
ROMID_t>>=8;
}
DS18B20_WriteByte(0xbe);
tempL = DS18B20_ReadByte();
tempH = DS18B20_ReadByte();
DS18B20_Reset();
if (tempH>7) return 0;
else return ((((uint16_t)tempH) << 8) | (uint16_t)tempL);
}
其中，“#define GPIO_EXEC_DELAY_us 8” 是做时序校正优化的参数，是GPIO代码驱动输出模式下的输出延时，因为DS18B20有三个时序关键点需要控制准确，所以要在这三个时序关键点进行时序校正优化：
-
总线复位后的响应的MCU采样时间点
-
写bit时序的开始15us低电平长度，保证DS18B20采样到正确状态
-
读bit时序的MCU采样时间点
STM32串口工程代码
这里在工程里引入usart.h和usart.c，便于调用print函数打印输出结果。
usart.h:
#ifndef _USART_H
#define _USART_H
#include "stm32g0xx_hal.h"
#include "stdio.h"
int fputc(int ch, FILE *f) ;
#endif
usart.c:
#include "usart.h"
extern UART_HandleTypeDef huart2; //声明串口
/* USER CODE BEGIN 1 */
#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
/**
* @brief Retargets the C library printf function to the USART.
* @param None
* @retval None
*/
PUTCHAR_PROTOTYPE
{
/* Place your implementation of fputc here */
/* e.g. write a character to the EVAL_COM1 and Loop until the end of transmission */
HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 0xFFFF);
return ch;
}
/* USER CODE END 1 */
STM32完整工程代码及效果
如下为STM32完整工程代码，首先读取ROM ID 并校验，然后进行温度的读取及串口输出：
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2022 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
//Written by Pegasus Yu in 2022
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "usart.h"
#include <stdio.h>
#include <stdlib.h>
uint8_t PY_CRC_8(uint8_t *di, uint32_t len)
{ //Written by Pegasus Yu 2022/04/22
uint16_t crc_poly = 0x0107; //X^8+X^2+X^1+1 total 9 effective bits. Computed total data shall be compensated 8-bit '0' before CRC computing.
uint8_t *datain;
uint64_t cdata = 0; //Computed total data
uint16_t data_t = 0; //Process data of CRC computing
uint16_t index_t = 63; ///bit shifting index for initial '1' searching
uint16_t index = 63; //bit shifting index for CRC computing
uint8_t rec = 0; //bit number needed to be compensated for next CRC computing
uint32_t cn=(len+1)/7;
uint32_t cr=(len+1)%7;
uint32_t j;
datain = malloc(len+1);
for(j=0;j<len;j++)
{
datain[j]=di[j];
}
datain[len]=0; //Compensate 8-bit '0' for input data
if(len<=7)
{
for(j=0;j<=len;j++)
{
cdata = (cdata<<8);
cdata = cdata|datain[j];
}
cn = 1;
}
else
{
if(cr==0)
{
cr=7;
}
else
{
cn++;
}
for(j=0;j<cr;j++)
{
cdata = (cdata<<8);
cdata = cdata|datain[j];
}
}
do
{
cn--;
while(index_t>0)
{
if( (cdata>>index_t)&1 )
{
index = index_t;
index_t = 0;
data_t |= (cdata>>(index-8));
{
data_t = data_t ^ crc_poly;
}
while((index!=0x5555)&&(index!=0xaaaa))
{
/*
if ((data_t>>7)&1) rec = 1;
else if ((data_t>>6)&1) rec = 2;
else if ((data_t>>5)&1) rec = 3;
else if ((data_t>>4)&1) rec = 4;
else if ((data_t>>3)&1) rec = 5;
else if ((data_t>>2)&1) rec = 6;
else if ((data_t>>1)&1) rec = 7;
else if ((data_t>>0)&1) rec = 8;
else rec = 9; */
for(uint8_t n=1;n<9;n++)
{
if ((data_t>>(8-n))&1) {rec = n;break;}
if (n==8) rec=9;
}
if((index-8)<rec)
{
data_t = data_t<<(index-8);
data_t |= (uint16_t)((cdata<<(64-(index-8)))>>(64-(index-8)));
index = 0x5555;
}
else
{
for(uint8_t i=1;i<=rec;i++)
{
data_t = (data_t<<1)|((cdata>>(index-8-i))&1) ;
}
if(rec!= 9)
{
data_t = data_t ^ crc_poly;
index -= rec;
}
else
{
data_t = 0;
index_t = index-8-1;
index = 0xaaaa;
}
}
}
if(index==0x5555) break;
}
else
{
index_t--;
if(index_t<8) break;
}
}
if(cn>0)
{
cdata = data_t&0x00ff;
for(uint8_t k=0;k<7;k++)
{
cdata = (cdata<<8);
cdata = cdata|datain[j++];
}
data_t = 0;
index_t = 63; ///bit shifting index for initial '1' searching
index = 63; //bit shifting index for CRC computing
rec = 0; //bit number needed to be compensated for next CRC computing
}
}
while(cn>0);
free(datain);
return (uint8_t)data_t;
}
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
#define DQ_0 HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_RESET);
#define DQ_1 HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_SET);
#define DQ_IS_LOW HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0)==0?1:0
#define CONVERSION_VOLTAGE 1 //0: DS18B20 constant VCC mode. 1: DS18B20 short term VCC mode only supplying for conversion process.
#define CV_ON HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_SET) //supply power to DS18B20 VCC
#define CV_OFF HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET) //not supply power to DS18B20 VCC
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
__IO float usDelayBase;
void PY_usDelayTest(void)
{
__IO uint32_t firstms, secondms;
__IO uint32_t counter = 0;
firstms = HAL_GetTick()+1;
secondms = firstms+1;
while(uwTick!=firstms) ;
while(uwTick!=secondms) counter++;
usDelayBase = ((float)counter)/1000;
}
void PY_Delay_us_t(uint32_t Delay)
{
__IO uint32_t delayReg;
__IO uint32_t usNum = (uint32_t)(Delay*usDelayBase);
delayReg = 0;
while(delayReg!=usNum) delayReg++;
}
void PY_usDelayOptimize(void)
{
__IO uint32_t firstms, secondms;
__IO float coe = 1.0;
firstms = HAL_GetTick();
PY_Delay_us_t(1000000) ;
secondms = HAL_GetTick();
coe = ((float)1000)/(secondms-firstms);
usDelayBase = coe*usDelayBase;
}
void PY_Delay_us(uint32_t Delay)
{
__IO uint32_t delayReg;
__IO uint32_t msNum = Delay/1000;
__IO uint32_t usNum = (uint32_t)((Delay%1000)*usDelayBase);
if(msNum>0) HAL_Delay(msNum);
delayReg = 0;
while(delayReg!=usNum) delayReg++;
}
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
#define GPIO_EXEC_DELAY_us 8
uint8_t DS18B20_Reset(void) //Bus reset timing in page 15 of spec
{
__disable_irq();
DQ_1;
PY_Delay_us_t(10); //Pull high, ready to send reset request
DQ_0;
PY_Delay_us_t(520); //Minimum 480us
DQ_1;
PY_Delay_us_t(15+55-GPIO_EXEC_DELAY_us);
if (DQ_IS_LOW)
{
PY_Delay_us_t(420);
__enable_irq();
return 1;
}
else
{
PY_Delay_us_t(420);
__enable_irq();
return 0;
}
}
void DS18B20_WriteByte(uint8_t val)
{
__disable_irq();
for (uint8_t i = 0; i < 8; i++)
{
DQ_0;
PY_Delay_us_t(15-GPIO_EXEC_DELAY_us);
if (val & 0x01)
{
DQ_1;
}
else
{
DQ_0;
}
PY_Delay_us_t(100);
DQ_1;
PY_Delay_us_t(4);
val >>= 1;
}
__enable_irq();
}
uint8_t DS18B20_ReadByte(void)
{
uint8_t read = 0;
__disable_irq();
for (uint8_t i = 0; i < 8; i++)
{
read >>= 1;
DQ_0;
PY_Delay_us_t(2);
DQ_1;
PY_Delay_us_t(12-GPIO_EXEC_DELAY_us);
if (!DQ_IS_LOW) read |= 0x80;
PY_Delay_us_t(50);
}
PY_Delay_us_t(60);
__enable_irq();
return read;
}
uint16_t DS18B20_ReadTempReg(void)
{
uint8_t tempL, tempH;
if(CONVERSION_VOLTAGE) CV_ON;
DS18B20_Reset();
DS18B20_WriteByte(0xcc);
DS18B20_WriteByte(0x44);
PY_Delay_us_t(2);
DQ_0;
PY_Delay_us_t(2);
DQ_1;
PY_Delay_us_t(800000); //conversion delay
if(CONVERSION_VOLTAGE) CV_OFF;
DS18B20_Reset();
DS18B20_WriteByte(0xcc);
DS18B20_WriteByte(0xbe);
tempL = DS18B20_ReadByte();
PY_Delay_us_t(60);
tempH = DS18B20_ReadByte();
DS18B20_Reset();
if (tempH>7) return 0;
else {return ((((uint16_t)tempH) << 8) | (uint16_t)tempL);}
}
uint64_t DS18B20_ReadID()
{
uint64_t ROMID=0;
uint8_t RD[8];
if (DS18B20_Reset() == 0)
{
return 0;
}
DS18B20_WriteByte(0x33);
for (uint8_t i = 0; i < 8; i++)
{
ROMID <<=8;
ROMID |= DS18B20_ReadByte();
}
DS18B20_Reset();
for(int8_t i=7;i>=0;i--)
{
RD[7-i] = (ROMID>>(i*8));
}
if (PY_CRC_8(RD, 7)==RD[7]) ROMID= *(uint64_t *)RD;
else ROMID = 0xFFFFFFFFFFFFFFFF;
return ROMID;
}
uint16_t DS18B20_ReadTempByID(uint64_t ROMID)
{
uint8_t tempL, tempH;
uint8_t i;
uint64_t ROMID_t = ROMID;
if(CONVERSION_VOLTAGE) CV_ON;
DS18B20_Reset();
DS18B20_WriteByte(0x55);
for (i = 0; i < 8; i++)
{
DS18B20_WriteByte((uint8_t)ROMID_t);
ROMID_t>>=8;
}
DS18B20_WriteByte(0x44);
PY_Delay_us_t(2);
DQ_0;
PY_Delay_us_t(2);
DQ_1;
PY_Delay_us_t(800000); //conversion delay
if(CONVERSION_VOLTAGE) CV_OFF;
ROMID_t = ROMID;
DS18B20_Reset();
DS18B20_WriteByte(0x55);
for (i = 0; i < 8; i++)
{
DS18B20_WriteByte((uint8_t)ROMID_t);
ROMID_t>>=8;
}
DS18B20_WriteByte(0xbe);
tempL = DS18B20_ReadByte();
tempH = DS18B20_ReadByte();
DS18B20_Reset();
if (tempH>7) return 0;
else return ((((uint16_t)tempH) << 8) | (uint16_t)tempL);
}
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint64_t ROM_ID;
uint8_t FAMILY_CODE;
uint64_t SERIAL_NUM;
uint16_t TData;
uint8_t TD_Flag; //temperature data flag(0:positive or 1:negative)
uint8_t TD_Absi; //temperature data absolute integral value
uint8_t TD_Absf; //temperature data absolute fraction value
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART2_UART_Init();
/* USER CODE BEGIN 2 */
PY_usDelayTest();
PY_usDelayOptimize();
ROM_ID = DS18B20_ReadID();
FAMILY_CODE = ROM_ID; //8-bit family code
SERIAL_NUM = (ROM_ID>>8)&0x0000ffffffffffff; //48-bit serial number
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
if(ROM_ID==0xffffffffffffffff)
{
TData = 0xffff;
printf("Read ROMID Error!!");
PY_Delay_us(100000);
}
else
{
printf("FAMILY_CODE: 0x%x\r\n", FAMILY_CODE);
PY_Delay_us(500);
printf("SERIAL_NUM: 0x%lx%lx\r\n", (uint32_t)(SERIAL_NUM>>32),(uint32_t)(SERIAL_NUM));
PY_Delay_us(500);
TData = DS18B20_ReadTempReg();
if ((TData&0x8000)==0)
{
TD_Flag = 0;
TD_Absi = TData/16;
TD_Absf = TData%16;
//|temperature|=TD_Absi+TD_Absf*0.0625
if(TD_Absf==0) printf("Current temperature is %u degree Celsius\r\n",TD_Absi);
else if(TD_Absf*625<1000) printf("Current temperature is %u.0%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
else printf("Current temperature is %u.%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
}
else
{
TD_Flag = 1;
TD_Absi = (0x10000 - TData)/16;
TD_Absf = (0x10000 - TData)%16;
//|temperature|=TD_Absi+TD_Absf*0.0625
if(TD_Absf==0) printf("Current temperature is -%u degree Celsius\r\n",TD_Absi);
else if(TD_Absf*625<1000) printf("Current temperature is -%u.0%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
else printf("Current temperature is -%u.%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
}
PY_Delay_us(1000);
printf("ROMID: 0x%lx%lx\r\n", (uint32_t)(ROM_ID>>32),(uint32_t)(ROM_ID));
PY_Delay_us(500);
TData = DS18B20_ReadTempByID(ROM_ID);
PY_Delay_us(500);
if ((TData&0x8000)==0)
{
TD_Flag = 0;
TD_Absi = TData/16;
TD_Absf = TData%16;
//|temperature|=TD_Absi+TD_Absf*0.0625
if(TD_Absf==0) printf("Current temperature is %u degree Celsius\r\n",TD_Absi);
else if(TD_Absf*625<1000) printf("Current temperature is %u.0%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
else printf("Current temperature is %u.%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
}
else
{
TD_Flag = 1;
TD_Absi = (0x10000 - TData)/16;
TD_Absf = (0x10000 - TData)%16;
//|temperature|=TD_Absi+TD_Absf*0.0625
if(TD_Absf==0) printf("Current temperature is -%u degree Celsius\r\n",TD_Absi);
else if(TD_Absf*625<1000) printf("Current temperature is -%u.0%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
else printf("Current temperature is -%u.%u degree Celsius\r\n",TD_Absi,TD_Absf*625);
}
PY_Delay_us(1000);
}
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV1;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV4;
RCC_OscInitStruct.PLL.PLLN = 64;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV4;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief USART2 Initialization Function
* @param None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 115200;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart2.Init.ClockPrescaler = UART_PRESCALER_DIV1;
huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_SET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET);
/*Configure GPIO pin : PA0 */
GPIO_InitStruct.Pin = GPIO_PIN_0;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pin : PA1 */
GPIO_InitStruct.Pin = GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
将ROM ID, FAMILY ID, SERIAL NUMBER交叉输出及温度输出的效果：
例程下载
STM32G030F6P6-DS18B20例程下载(STM32CUBEIDE工程)
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