🌡️ DS18B20 Temperature Sensor Library for STM32

A lightweight and non-blocking DS18B20 driver written in C for STM32 (HAL-based).

Built on top of the non-blocking 1-Wire library, it allows reading temperature from one or multiple DS18B20 devices without blocking the CPU.

It supports:

• 🌡️ DS18B20 – 9–12 bit temperature sensor (Celsius & Fahrenheit)

The library is designed for:

• Applications requiring non-blocking temperature acquisition
• Multi-device support on a single 1-Wire bus
• STM32 projects across All families

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✨ Features

• 🔹 Non-blocking operation using timer callbacks
• 🔹 Supports multiple DS18B20 devices (OW_MAX_DEVICE)
• 🔹 Configurable resolution (9–12 bit)
• 🔹 Temperature read in Celsius and Fahrenheit
• 🔹 Alarm threshold configuration
• 🔹 Works with any GPIO pins
• 🔹 Built on top of HAL-compatible 1-Wire library

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⚙️ Installation

1. Copy files directly

Add these files to your STM32 project:

• ds18b20.h
• ds18b20.c
• Ensure One-Wire Library added, https://github.com/nimaltd/ow

2. STM32Cube Pack Installer (Recommended)

Not yet available; include files manually for now.

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🔧 Configuration (ds18b20_config_t)

Set conversion resolution and alarm thresholds (Not yet available):

ds18b20_config_t ds18_conf = {
    .alarm_high = 50,           // High temperature alarm
    .alarm_low  = -50,          // Low temperature alarm
    .cnv_bit    = DS18B20_CNV_BIT_12  // Resolution (9–12 bit)
};

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🛠 CubeMX Setup

Read in One-Wire Reopository

🚀 Quick Start

Include header

#include "ds18b20.h"

Define a handle

ds18b20_t ds18;

Timer callback

void ds18_tim_cb(TIM_HandleTypeDef *htim)
{
    ow_callback(&ds18.ow);
}

Optional done callback

void ds18_done_cb(ow_err_t error)
{
}

Initialize DS18B20 in main.c

ow_init_t ow_init_struct;
ow_init_struct.tim_handle = &htim1;
ow_init_struct.gpio = GPIOC;
ow_init_struct.pin = GPIO_PIN_8;
ow_init_struct.tim_cb = ds18_tim_cb;
ow_init_struct.done_cb = NULL;   // Optional
ow_init_struct.rom_id_filter = DS18B20_ID;

ds18b20_init(&ds18, &ow_init_struct);

// Update ROM IDs for all devices
ds18b20_update_rom_id(&ds18);
while(ds18b20_is_busy(&ds18));

// Configure alarm thresholds and resolution
ds18b20_config_t ds18_conf = {
    .alarm_high = 50,
    .alarm_low = -50,
    .cnv_bit = DS18B20_CNV_BIT_12
};
ds18b20_conf(&ds18, &ds18_conf);
while(ds18b20_is_busy(&ds18));

Read temperatures

int16_t temp_c[2];

while(1) {
    ds18b20_cnv(&ds18);
    while(ds18b20_is_busy(&ds18));
    while(!ds18b20_is_cnv_done(&ds18));

    ds18b20_req_read(&ds18, 0);
    while(ds18b20_is_busy(&ds18));
    temp_c[0] = ds18b20_read_c(&ds18);

    ds18b20_req_read(&ds18, 1);
    while(ds18b20_is_busy(&ds18));
    temp_c[1] = ds18b20_read_c(&ds18);
}

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🧰 API Overview

| Function | Description | |----------|-------------| | ds18b20_init() | Initialize DS18B20 driver handle | | ds18b20_is_busy() | Check if bus is busy | | ds18b20_last_error() | Get last error | | ds18b20_update_rom_id() | Update connected ROM IDs | | ds18b20_cnv() | Start temperature conversion | | ds18b20_conf() | Set configuration (alarm/resolution) | | ds18b20_is_cnv_done() | Check if conversion is done | | ds18b20_req_read() | Request temperature read | | ds18b20_read_c() | Read temperature in Celsius | | ds18b20_read_f() | Convert Celsius to Fahrenheit |

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💖 Support

If you find this project useful, please ⭐ star the repo and support!

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📜 License

Licensed under the terms in the LICENSE.

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