66 lines
2.5 KiB
Markdown
66 lines
2.5 KiB
Markdown
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# esp32-ds18b20
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## Introduction
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This is a ESP32-compatible C component for the Maxim Integrated DS18B20 Programmable Resolution 1-Wire Digital Thermometer device.
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It supports multiple devices on the same 1-Wire bus.
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It is written and tested for v2.1 and v3.0 of the [ESP-IDF](https://github.com/espressif/esp-idf) environment, using the xtensa-esp32-elf toolchain (gcc version 5.2.0).
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## Dependencies
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Requires [esp32-owb](https://github.com/DavidAntliff/esp32-owb).
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## Example
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See [esp32-ds18b20-example](https://github.com/DavidAntliff/esp32-ds18b20-example) for an example that supports single and multiple devices on a single bus.
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## Features
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In cooperation with the underlying esp32-owb component, this component includes:
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* External power supply mode (parasitic mode not yet supported).
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* Static (stack-based) or dynamic (malloc-based) memory model.
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* No globals - support any number of DS18B20 devices on any number of 1-Wire buses simultaneously.
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* 1-Wire device detection and validation, including search for multiple devices on a single bus.
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* Addressing optimisation for a single (solo) device on a bus.
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* CRC checks on temperature data.
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* Programmable temperature measurement resolution (9, 10, 11 or 12-bit resolution).
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* Temperature conversion and retrieval.
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* Separation of conversion and temperature retrieval to allow for simultaneous conversion across multiple devices.
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## Documentation
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Automatically generated API documentation (doxygen) is available [here](https://davidantliff.github.io/esp32-ds18b20/index.html).
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## Source Code
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The source is available from [GitHub](https://www.github.com/DavidAntliff/esp32-ds18b20).
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## License
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The code in this project is licensed under the MIT license - see LICENSE for details.
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## Links
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* [DS18B20 Datasheet](http://datasheets.maximintegrated.com/en/ds/DS18B20.pdf)
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* [1-Wire Communication Through Software](https://www.maximintegrated.com/en/app-notes/index.mvp/id/126)
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* [1-Wire Search Algorithm](https://www.maximintegrated.com/en/app-notes/index.mvp/id/187)
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* [Espressif IoT Development Framework for ESP32](https://github.com/espressif/esp-idf)
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## Acknowledgements
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Parts of this code are based on references provided to the public domain by Maxim Integrated.
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"1-Wire" is a registered trademark of Maxim Integrated.
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## Roadmap
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The following features are anticipated but not yet implemented:
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* Concurrency support (multiple tasks accessing devices on the same bus).
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* Alarm support.
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* EEPROM support.
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* Parasitic power support.
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