components/esp32-ds18b20/README.md@1ab1f4a8c328
components/esp32-ds18b20/README.md
Sat, 14 Mar 2020 13:07:02 +0100
- author
- Michiel Broek <mbroek@mbse.eu>
- date
- Sat, 14 Mar 2020 13:07:02 +0100
- changeset 47
- 1ab1f4a8c328
- parent 0
- 88d965579617
- permissions
- -rw-r--r--
Version 0.2.2 Changed to use a permanent network and WiFi connection. Removed three mainloop stages. Removed MQTT sequence counter that was not used. Update WiFi rssi status during eacht measure cycle. Changed FreeRTOS schedulng to 500 Hz.
# 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.
