https://github.com/azogue/i2csense
Another library to handle sensors connected via I2c bus (SDA, SCL pins) to the Raspberry Pi
https://github.com/azogue/i2csense
home-automation i2c-bus i2c-sensors raspberry-pi smbus
Last synced: about 1 year ago
JSON representation
Another library to handle sensors connected via I2c bus (SDA, SCL pins) to the Raspberry Pi
- Host: GitHub
- URL: https://github.com/azogue/i2csense
- Owner: azogue
- License: mit
- Created: 2017-06-16T12:56:57.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2017-06-29T08:38:16.000Z (almost 9 years ago)
- Last Synced: 2025-04-11T16:13:08.820Z (about 1 year ago)
- Topics: home-automation, i2c-bus, i2c-sensors, raspberry-pi, smbus
- Language: Python
- Size: 20.5 KB
- Stars: 4
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
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README
# i2csense
Another library to handle sensors connected via **[I2c](https://en.wikipedia.org/wiki/I²C) bus** (SDA, SCL pins) to your **[Raspberry Pi](https://www.raspberrypi.org/)**.
This library implements the following i2c sensors:
- **[Bosch BME280 Environmental sensor (temperature, humidity and pressure)](https://cdn-shop.adafruit.com/datasheets/BST-BME280_DS001-10.pdf)**
- **[HTU21D temperature and humidity sensor](http://www.datasheetspdf.com/PDF/HTU21D/779951/1)**
- **[BH1750FVI light level sensor](http://cpre.kmutnb.ac.th/esl/learning/bh1750-light-sensor/bh1750fvi-e_datasheet.pdf)**
## Installation
This library needs the **i2c bus** to be enabled, and uses the `smbus-cffi` module to communicate with it, so, before installing with `pip`, make sure the bus is enabled, and the necessary dependencies are available:
### Directions for installing smbus support on Raspberry Pi:
Enable I2c interface with the Raspberry Pi config utility:
```bash
# Enable i2c interface
sudo raspi-config
```
Select `Interfacing options->I2C` choose `` and hit `Enter`, then go to `Finish` and you'll be prompted to reboot.
Install dependencies for use the `smbus-cffi` module and reboot:
```bash
sudo apt-get install build-essential libi2c-dev i2c-tools python-dev libffi-dev
sudo reboot
```
###### Check the i2c address of the sensors
After installing `i2c-tools`, a new utility is available to scan the addresses of the connected sensors:
```bash
/usr/sbin/i2cdetect -y 1
```
It will output a table like this:
```text
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- 23 -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: 40 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- 77
```
So you can see three sensors are present at **0x23 (BH1750)**, **0x40 (HTU21D)** and **0x77 (BME280)** addresses.
### Install with pip
Finally, in your python environment,
```bash
pip install i2csense
```
## Usage
This library is intended to be used by other applications, where sensors are instantiated with their configuration parameters, to be read at the desired intervals.
However, if you want to use as a simple logger via command line, a simple CLI is also available to test the sensors.
```python
import smbus
from i2csense.bme280 import BME280
bus = smbus.Bus(1)
sensor = BME280(bus)
delta_secs = 5
while True:
sensor.update()
if not sensor.sample_ok:
print("An error has occured")
break
print(sensor.current_state_str)
sleep(delta_secs)
```
**CLI usage**
Find sensors:
```bash
i2csense
# or specify the i2c bus:
i2csense -b 0
```
Test sensors:
```bash
# Test BME280 sensor with default params:
i2csense -s bme280
# Test BME280 sensor with custom params every 10 secs:
i2csense -d 10 --bus 0 --address 0x77 --sensor bme280 --params osrs_t=4 osrs_p=4 osrs_h=4 mode=2 filter_mode=1
```
## Changelog
- **v0.0.1**: First release with 3 sensors: **BME280, BH1750, HTU21D**.
- **v0.0.2**: Minor fixes.
- **v0.0.3**: Minor fixes for `BH1750`, fix `README.rst`.
- **v0.0.4**: Soft reset of `HTU21D` after bad sample, to restart sensor.
## TODO:
- **Append more sensors**.
- finish CLI interface with better help and more configuration options.
Although the library only covers three sensors, it would be ideal to continue completing it with more sensors or actuators running in the i2c bus, so I encourage you to contribute with more sensors, or to copy, change, edit, or suggest any changes.