https://github.com/electromake/usb-thermometer-python
Python library for USB Thermometer (DS18B20 sensor).
https://github.com/electromake/usb-thermometer-python
ds18b20 electromake iot python raspberry-pi thermometer usb usb-thermometer
Last synced: 2 months ago
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Python library for USB Thermometer (DS18B20 sensor).
- Host: GitHub
- URL: https://github.com/electromake/usb-thermometer-python
- Owner: electromake
- Created: 2025-02-20T23:39:12.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2025-03-05T14:35:59.000Z (over 1 year ago)
- Last Synced: 2025-12-25T18:59:28.657Z (6 months ago)
- Topics: ds18b20, electromake, iot, python, raspberry-pi, thermometer, usb, usb-thermometer
- Language: Python
- Homepage: https://electromake.pl/
- Size: 21.5 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# USB Thermometer Python library
## Overview
This project provides a Python 3 library for interfacing with DS18B20 temperature sensors via a USB-based 1-Wire interface. The library implements the 1-Wire protocol over a serial port, allowing you to discover connected sensors, read temperature measurements, configure sensor settings (precision, alarm thresholds), and perform low-level bit manipulations required for proper communication with the sensors.
## Features
- **Sensor Discovery:** Detect all DS18B20 sensors on the 1-Wire bus.
- **Temperature Reading:** Continuously read sensor temperature values.
- **Sensor Configuration:** Write to and read from the sensor scratchpad, set measurement precision and alarm thresholds.
- **Utilities:** Functions for converting bit lists to hexadecimal strings/bytearrays and computing CRC8 checksums.
- **Examples:** Three comprehensive examples demonstrate:
1. Discovering sensors and continuously reading their temperatures.
2. Storing sensor data in an SQL database using SQLAlchemy.
3. Configuring sensor settings (precision and alarm thresholds).
## Project Structure
- **wire.py**
Implements the `USBThermometer` class which manages communication with DS18B20 sensors via a serial port.
- **sensors.py**
Contains the `DS18B20` class that represents individual temperature sensors, handling their ROM codes, serial numbers, and configuration registers.
- **utils.py**
Provides utility functions for bit manipulation, hexadecimal conversion, and CRC8 calculation.
- **tests**
Unit tests for verifying the functionality of the library.
- **examples**
Example scripts demonstrating different use cases:
- `example1.py`: Discover sensors and continuously read temperatures until interrupted.
- `example2.py`: Record sensor samples to a SQL database (SQLite or PostgreSQL) using SQLAlchemy.
- `example3.py`: Configure sensor settings such as precision and alarm thresholds.
## Installation
1. **Clone the repository:**
```bash
git clone https://github.com/electromake/usb-thermometer-python.git
cd usb-thermometer-python
```
2. **Install required dependencies:**
```bash
pip install pyserial sqlalchemy
# If you would like to run SQL example, run also:
pip install sqlalchemy
```
## Usage
### Example 1: Continuous Temperature Reading
Discover all sensors and continuously read their temperatures until a keyboard interrupt (Ctrl+C) is detected.
```bash
python example1.py
```
### Example 2: Storing Sensor Samples in a Database
Discover sensors and store temperature samples (with timestamps) in a SQL database. The database contains two tables: one for sensor details (ROM codes) and one for temperature samples.
```bash
python example2.py
```
### Example 3: Configuring Sensor Settings
Configure sensor settings by adjusting measurement precision and alarm thresholds. The example shows how to write new settings to the sensor's scratchpad and verify them.
```bash
python example3.py
```
### Testing
To run the unit tests, execute:
```bash
python -m unittest discover
```
### More resources
- [DS18B20 Datasheet](https://www.analog.com/media/en/technical-documentation/data-sheets/DS18B20.pdf)
- [1-wire serial port implementation](https://www.analog.com/en/resources/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html)
### Author
Electromake
[https://electromake.pl/](https://electromake.pl)