components/esp32-owb/README.md@d0a74a6a9a02 (annotated)
components/esp32-owb/README.md
Mon, 24 Jun 2024 20:55:35 +0200
- author
- Michiel Broek <mbroek@mbse.eu>
- date
- Mon, 24 Jun 2024 20:55:35 +0200
- branch
- idf 5.1
- changeset 131
- d0a74a6a9a02
- parent 129
- 31f9d3e4a85f
- permissions
- -rw-r--r--
IDF code size optimisations, reduced binary 157.379 bytes. Now it fits in the partitions.
| 0 | 1 | # esp32-owb |
| 2 | ||
| 3 | This is a ESP32-compatible C component for the Maxim Integrated "1-Wire" protocol. | |
| 4 | ||
| 129 | 5 | It is written for the `idf.py` target `esp32`, although it may work on other ESP-32 devices with minor modifications. |
| 6 | ||
| 7 | It is tested for version 4.4.4 and 5.0.1 of the [ESP-IDF](https://github.com/espressif/esp-idf) environment. | |
| 0 | 8 | |
| 129 | 9 | Legacy support for v2.1 is available on the [ESP-IDF_v2.1](https://github.com/DavidAntliff/esp32-owb/tree/ESP-IDF_v2.1) branch. This is no longer maintained. |
| 10 | ||
| 11 | Legacy support for v3.0-v3.3 and v4.1-beta1 is available on the [ESP-IDF_v3.0-3.3_4.1-beta1](https://github.com/DavidAntliff/esp32-owb/tree/ESP-IDF_v3.0-3.3_4.1-beta1) branch. This is no longer maintained. | |
| 0 | 12 | |
| 13 | ## Features | |
| 14 | ||
| 15 | This library includes: | |
| 16 | ||
| 129 | 17 | * External power supply mode. |
| 18 | * Parasitic power mode. | |
| 0 | 19 | * Static (stack-based) or dynamic (malloc-based) memory model. |
| 20 | * No globals - support any number of 1-Wire buses simultaneously. | |
| 21 | * 1-Wire device detection and validation, including search for multiple devices on a single bus. | |
| 22 | * Addressing optimisation for a single (solo) device on a bus. | |
| 23 | * 1-Wire bus operations including multi-byte read and write operations. | |
| 24 | * CRC checks on ROM code. | |
| 25 | ||
| 26 | This component includes two methods of bus access - delay-driven GPIO and RMT-driven slots. | |
| 27 | The original implementation used CPU delays to construct the 1-Wire read/write timeslots | |
| 28 | however this proved to be too unreliable. A second method, using the ESP32's RMT peripheral, | |
| 29 | results in very accurate read/write timeslots and more reliable operation. | |
| 30 | ||
| 129 | 31 | Therefore I highly recommend that you use the RMT driver. *The GPIO driver is deprecated and will be removed.* |
| 32 | ||
| 33 | See documentation for [esp32-ds18b20](https://www.github.com/DavidAntliff/esp32-ds18b20#parasitic-power-mode) | |
| 34 | for further information about parasitic power mode, including strong pull-up configuration. | |
| 0 | 35 | |
| 36 | ## Documentation | |
| 37 | ||
| 38 | Automatically generated API documentation (doxygen) is available [here](https://davidantliff.github.io/esp32-owb/index.html). | |
| 39 | ||
| 40 | ## Source Code | |
| 41 | ||
| 42 | The source is available from [GitHub](https://www.github.com/DavidAntliff/esp32-owb). | |
| 43 | ||
| 44 | ## License | |
| 45 | ||
| 46 | The code in this project is licensed under the MIT license - see LICENSE for details. | |
| 47 | ||
| 48 | ## Links | |
| 49 | ||
| 129 | 50 | * [esp32-ds18b20](https://github.com/DavidAntliff/esp32-ds18b20) - ESP32-compatible DS18B20 Digital Thermometer |
| 51 | component for ESP32 | |
| 0 | 52 | * [1-Wire Communication Through Software](https://www.maximintegrated.com/en/app-notes/index.mvp/id/126) |
| 53 | * [1-Wire Search Algorithm](https://www.maximintegrated.com/en/app-notes/index.mvp/id/187) | |
| 54 | * [Espressif IoT Development Framework for ESP32](https://github.com/espressif/esp-idf) | |
| 55 | ||
| 56 | ## Acknowledgements | |
| 57 | ||
| 129 | 58 | Thank you to [Chris Morgan](https://github.com/chmorgan) for his contribution of adding RMT peripheral support for more |
| 59 | reliable operation. | |
| 0 | 60 | |
| 61 | Parts of this code are based on references provided to the public domain by Maxim Integrated. | |
| 62 | ||
| 63 | "1-Wire" is a registered trademark of Maxim Integrated. |
