用stm32G431写出DS18B20的读取温度的代码

以下是使用STM32G431读取DS18B20温度传感器的代码：

#include "stm32g4xx_hal.h"

#define DS18B20_PORT GPIOA
#define DS18B20_PIN GPIO_PIN_0

void delay_us(uint32_t us)
{
    uint32_t ticks = us * (SystemCoreClock / 1000000);
    __HAL_TIM_SET_COUNTER(&htim6, 0);
    while (__HAL_TIM_GET_COUNTER(&htim6) < ticks);
}

void ds18b20_write_bit(uint8_t bit)
{
    HAL_GPIO_WritePin(DS18B20_PORT, DS18B20_PIN, GPIO_PIN_RESET);
    delay_us(2);
    if (bit) {
        HAL_GPIO_WritePin(DS18B20_PORT, DS18B20_PIN, GPIO_PIN_SET);
    }
    delay_us(60);
    HAL_GPIO_WritePin(DS18B20_PORT, DS18B20_PIN, GPIO_PIN_SET);
}

uint8_t ds18b20_read_bit(void)
{
    uint8_t bit = 0;
    HAL_GPIO_WritePin(DS18B20_PORT, DS18B20_PIN, GPIO_PIN_RESET);
    delay_us(2);
    HAL_GPIO_WritePin(DS18B20_PORT, DS18B20_PIN, GPIO_PIN_SET);
    delay_us(15);
    bit = HAL_GPIO_ReadPin(DS18B20_PORT, DS18B20_PIN);
    delay_us(45);
    return bit;
}

void ds18b20_write_byte(uint8_t byte)
{
    uint8_t i;
    for (i = 0; i < 8; i++) {
        ds18b20_write_bit(byte & 0x01);
        byte >>= 1;
    }
}

uint8_t ds18b20_read_byte(void)
{
    uint8_t i, byte = 0;
    for (i = 0; i < 8; i++) {
        byte >>= 1;
        byte |= (ds18b20_read_bit() << 7);
    }
    return byte;
}

void ds18b20_convert_temperature(void)
{
    ds18b20_write_byte(0xCC);
    ds18b20_write_byte(0x44);
}

float ds18b20_read_temperature(void)
{
    uint8_t temperature_l, temperature_h;
    int16_t temperature;
    float temp;
    ds18b20_write_byte(0xCC);
    ds18b20_write_byte(0xBE);
    temperature_l = ds18b20_read_byte();
    temperature_h = ds18b20_read_byte();
    temperature = (temperature_h << 8) | temperature_l;
    temp = (float)temperature / 16.0;
    return temp;
}

int main(void)
{
    HAL_Init();
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_TIM6_CLK_ENABLE();
    TIM6->PSC = SystemCoreClock / 1000000 - 1;
    TIM6->ARR = 0xFFFF;
    TIM6->CR1 = TIM_CR1_CEN;
    while (1) {
        ds18b20_convert_temperature();
        HAL_Delay(800);
        float temp = ds18b20_read_temperature();
        // do something with temp
    }
}

这段代码使用STM32G431读取DS18B20温度传感器的温度值。它使用GPIOA的第0个引脚来连接DS18B20传感器。在主函数中，它会不断地读取温度值并将其存储在temp变量中，你可以根据需要对其进行处理。