How to create a Ready-to-use STM32CubeIDE project for DS18B20?

 Here's a step-by-step guide to create a ready-to-use STM32CubeIDE project for reading temperature from the DS18B20 sensor using STM32 HAL. The example assumes you're using STM32F103C8T6 ("Blue Pill") but can be adapted to other STM32 chips.

---

Project Overview

• Microcontroller: STM32F103C8T6

• Sensor: DS18B20

• Interface: 1-Wire protocol (bit-banged using GPIO)

• Development Tool: STM32CubeIDE

• Library: MaJerle's OneWire and DS18B20 drivers (HAL-compatible)

---

Wiring Recap

DS18B20 Pin	Connect To STM32
GND	GND
VDD	3.3V
DQ	PA1 (or your chosen GPIO)
4.7 kΩ	Between DQ and VDD

Project Setup Steps

 1. Create a New Project

• Open STM32CubeIDE

• File → New → STM32 Project

• Select STM32F103C8T6 (or your MCU)

• Name your project: DS18B20_Project

---

 2. Configure GPIO

• Open .ioc file

• Set PA1 as GPIO_Output

• Enable USART1 (optional, for serial print/debug)

• Enable SYS → Debug: Serial Wire (for SWD debugging)

---

 3. Add DS18B20 + OneWire HAL Libraries

You can use MaJerle’s libraries:

• Download from GitHub:
  https://github.com/MaJerle/OneWire

Files to Add:

• on1wire.c, on1wire.h

• ds18b20.c, ds18b20.h

• Add them to Core/Src/ and Core/Inc/ folders in CubeIDE.

 Modify onewire.c/h:

• Set ONEWIRE_MAX_DEV = 1 if using 1 sensor.

• Set the correct GPIO and PORT used (PA1).

---

 4. Main Code (main.c)

Inside main.c, modify like this:

c

#include "onewire.h"
#include "ds18b20.h"
#include "stdio.h"

float temp;
char buffer[32];

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_USART1_UART_Init(); // Optional

  OneWire_t ow;
  OneWire_Init(&ow, GPIOA, GPIO_PIN_1); // PA1

  uint8_t rom[8];
  if (OneWire_Search(&ow, rom)) {
    while (1)
    {
      DS18B20_Start(&ow, rom, DS18B20_Resolution_12bits);
      HAL_Delay(750); // Max conversion time
      temp = DS18B20_ReadTemperature(&ow, rom);

      sprintf(buffer, "Temp: %.2f C\r\n", temp);
      HAL_UART_Transmit(&huart1, (uint8_t*)buffer, strlen(buffer), HAL_MAX_DELAY);

      HAL_Delay(1000);
    }
  } else {
    // No sensor found
    while (1) {
      HAL_UART_Transmit(&huart1, (uint8_t*)"No DS18B20\r\n", 12, HAL_MAX_DELAY);
      HAL_Delay(1000);
    }
  }
}

---

Build and Flash

• Press Build 

• Flash using ST-Link or USB-UART (e.g. via bootloader)

• Open serial monitor at 9600 baud to view temperature readings

---

Helpful Notes

• You can use CubeMX middleware for UART or printf if needed.

• For multiple sensors, use OneWire_Search and loop through detected ROMs.

• For STM32F4, replace HAL GPIO setup and clocks accordingly.