2.5 KiB
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 environment, using the xtensa-esp32-elf toolchain (gcc version 5.2.0).
Dependencies
Requires esp32-owb.
Example
See 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.
Source Code
The source is available from GitHub.
License
The code in this project is licensed under the MIT license - see LICENSE for details.
Links
- DS18B20 Datasheet
- 1-Wire Communication Through Software
- 1-Wire Search Algorithm
- Espressif IoT Development Framework for ESP32
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.