One wire interface fr STM32G474MBT6

sreejithrnair2026 · ‎2026-02-06

I want to interface STM32G474 MCU with DS18B20 digital temperature probe in my project. The DS18B20 uses one-wire interface. Is one wire interface supported with this MCU?

Kindly provide a detailed explanation. Help please.

Datasheet link for DS1B20: EVVO DS18B20Axx

Regards,
Sreejith

Andrew Neil · ‎2026-02-09

@sreejithrnair2026 wrote:
do not have any UARTs free and all the UARTs are occupied.

You can take a similar approach to synthesising 1-Wire using SPI ...

See:

https://community.st.com/t5/stm32-mcus-embedded-software/ds2431-read-rom-returns-0x00-on-stm32f446re/m-p/845399/highlight/true#M68752

Note also that Analog Devices (who are now the manufacturers, since they acquired Maxim) have various bridge chips to connect 1-Wire to more widely supported interfaces; eg, I2C:

https://www.analog.com/en/products/ds2482-100.html

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

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mƎALLEm · ‎2026-02-06

Hello @sreejithrnair2026 and welcome to the ST community,

The protocol used by this sensor is not supported natively by the MCU. You need to use GPIO and may be a timer to communicate with a such sensor.

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Uwe Bonnes · ‎2026-02-06

You can easily implement one-wire with an uart. Uart Feature of G4 like logic inversion, open drain and half duplex mode allows implementation with one pullup.

mƎALLEm · ‎2026-02-06

And it seems others already implemented that:

Example: https://github.com/nimaltd/ds18b20/tree/master

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sreejithrnair2026 · ‎2026-02-09

Thanks for sharing the implemented code. In my case, I do not have any UARTs free and all the UARTs are occupied. So, I can only use the option of bit banging for 1 wire interface.

Uwe Bonnes · ‎2026-02-09

Try to use the timer so you have constant timing. GPIO bitbanging will easily be disturbed by other interrupts...

mƎALLEm · ‎2026-02-09

Hello @sreejithrnair2026 ,

Look at the link I have shared it uses GPIO + timer to read and write data:

The link to the one wire library:

https://github.com/nimaltd/ow/tree/main

Used by a higher level library: ds18b20: https://github.com/nimaltd/ds18b20/tree/master

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Andrew Neil · ‎2026-02-09

@sreejithrnair2026 wrote:
do not have any UARTs free and all the UARTs are occupied.

You can take a similar approach to synthesising 1-Wire using SPI ...

See:

https://community.st.com/t5/stm32-mcus-embedded-software/ds2431-read-rom-returns-0x00-on-stm32f446re/m-p/845399/highlight/true#M68752

Note also that Analog Devices (who are now the manufacturers, since they acquired Maxim) have various bridge chips to connect 1-Wire to more widely supported interfaces; eg, I2C:

https://www.analog.com/en/products/ds2482-100.html

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

sreejithrnair2026 · ‎2026-02-09

Thank you Andrew. Really appreciate your support.

Regards

mƎALLEm · ‎2026-02-09

@sreejithrnair2026 ,

If your question has been answered, please accept as solution the post that has answered it.

To give better visibility on the answered topics, please click on "Accept as Solution" on the reply which solved your issue or answered your question.