A lightweight and efficient 1-Wire protocol library written in C for STM32 (HAL-based).

Unlike blocking implementations, this library uses asynchronous, non-blocking operation driven by a single timer interrupt.
It can run on any GPIO pins.

It supports a wide range of Maxim/Dallas devices, including:

• 🌡️ DS18B20 – Temperature sensor
• 🔋 DS2431 – EEPROM
• 🔐 DS28E17 – I²C master bridge
• 🔒 DS1990A iButton – Authentication token
• ⚡ Any other standard 1-Wire device

The library is designed for:

• Projects where CPU blocking must be avoided
• Applications that need multi-device 1-Wire bus support
• Easy portability across different STM32 families (F0/F1/F3/F4/F7/G0/G4/H7, etc.)

• 🔹 Single or multiple device support (OW_MAX_DEVICE)
• 🔹 Full STM32 HAL compatibility
• 🔹 ROM ID operations (read, match, skip, search)
• 🔹 Robust error handling (reset, bus, ROM, length)
• 🔹 Non-blocking operation via timer callbacks
• 🔹 Clean and modular API
• 🔹 Support Single and Dual pins (for insolation circuits)

You can install in two ways:

Add these files to your STM32 project:

• ow.h
• ow.c
• ow_config.h

Available in the official pack repo:
👉 STM32-PACK (Not Ready)

Defines library limits and timing values. Example:

#define OW_MAX_DEVICE     4      // Max number of devices
#define OW_MAX_DATA_LEN   32     // Max data length
#define OW_DUAL_PINS      0      // Enable if using dual pins(TX/RX) for isolation 

1. GPIO Pin

   • Configure as Output Open-Drain (e.g., PC8).
   • In dual pins mode, set TX pin as Output Push-PULL and set RX pin as ** INPUT ** (e.g., PC8, PC7).

2. Timer

   • Use internal clock source.
   • Prescaler set for 1 µs tick.
     • Example: 170 MHz bus → Prescaler = 170 - 1.
   • Enable Timer NVIC interrupt.
   • In Project Manager → Advanced Settings, enable Register Callback for the timer.
   • In Project Manager → Code Generator, enable Generate Peripheral initialization as a pair ".c/.h" files per peripheral.

#include "ow.h"

ow_handle_t ds18;

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

void ds18_done_cb(ow_err_t error)
{
}

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 = ds18_done_cb;   // Optional: callback when transfer is done, or can use NULL
ow_init_struct.rom_id_filter = 0;        // 0 = Accept All, or use a value. (Available if OW_MAX_DEVICE > 1) 

ow_init(&ds18, &ow_init_struct);

Now the library is ready—use any ow_* functions.

uint8_t data[16];
ow_update_rom_id(&ds18);
while (ow_is_busy(&ds18));
HAL_Delay(10);
ow_xfer_by_id(&ds18, 0, 0x44, NULL, 0, 0);
HAL_Delay(1000);
ow_xfer_by_id(&ds18, 0, 0xBE, NULL, 0, 9);
while (ow_is_busy(&ds18));
ow_read_resp(&ds18, data, 16);

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Licensed under the terms in the LICENSE.