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