💧 Kernel space driver for Bosch Sensortec BME280
The driver allows using the sensor via I2C bus on a single-board computer like Raspberry Pi, Orange Pi, Asus Tinker Board, etc.
[](LICENSE) [][github-pre-commit] [][pre-commit.ci]   [][github-markdownlint] [][github-commitlint]  [][raspberrypi] [][tinker-board]
🎉 Features
- 🗃️ Provides an interface in sysfs and procfs for sensor settings, calibration data, measurements
- ⚙️ Supports multiple sensors on the same I2C adapter
- 🔌 Supports multiple I2C adapters
- ⚗️ Tested on: Rasbperry Pi 3B+, Asus Tinker Board
🌻 Motivation
Final project for my education in Linux Kernel GL BaseCamp. I participated in the course from November 2019 until March 2020.
✨ Getting Started
📚 Prerequisites
Firstly you will need to install build dependencies such as compiler
(build-essential, g++-arm-linux-gnueabihf, gdb-multiarch) and
linux-headers. Next, you will need to get source code for exact kernel version
you are running. You can find the kernel version via uname -r.
📦 Installation
- Clone the Repository
- Build this Kernel Module (
make clean modules_release) - Install this Kernel Module (
make modules_install)
👀 Usage
- Connect the sensor to your host
- Scan I2C bus to find the sensor address (
i2cdetect) - Initialize the sensor from user space (
echo "bme280 'your address, usually 0x76 or 0x77'" > /sys/bus/i2c/devices/i2c-'your adapter number'/new_device)
❓ FAQs
🙋♂️ How to access sensor settings, calibration data, measurements?
👉 sysfs – filesystem for exporting kernel objects
| Mapping | Operations | Description | | ------------------------------ | ---------- | ------------------------------ | | /sys/class/bme280/i2c | read/write | I2C adapter and device address | | /sys/class/bme280/chip_id | read | Chip identifier | | /sys/class/bme280/reset | write | Reset | | /sys/class/bme280/mode | read/write | Power mode | | /sys/class/bme280/osrs_p | read/write | Pressure oversampling | | /sys/class/bme280/osrs_t | read/write | Temperature oversampling | | /sys/class/bme280/osrs_h | read/write | Humidity oversampling | | /sys/class/bme280/filter | read/write | Filter coefficient | | /sys/class/bme280/standby_time | read/write | Standby time | | /sys/class/bme280/pressure | read | Pressure (Pa) | | /sys/class/bme280/temperature | read | Temperature (°C * 100) | | /sys/class/bme280/humidity | read | Humidity (% * 1024) |
👉 procfs – process information pseudo-filesystem
| Mapping | Operations | Description | | ----------------- | ---------- | ----------------------------- | | /proc/bme280info | read | Device information as a table | | /proc/bme280calib | read | Calibration data as a table |
🙋♂️ How to switch to another sensor?
👉 If you want to switch to another sensor, use /sys/bme280/i2c
mapping, write to it a number of I2C adapter in decimal and device address in
hex (echo "0 0x77" > /sys/bme280/i2c).
🛠️ Tech Stack
✍️ Contributing
👍🎉 First off, thanks for taking the time to contribute! 🎉👍
Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are greatly appreciated.
- Fork the Project
- Create your Feature Branch (
git checkout -b feature/awesome-feature) - Commit your Changes (
git commit -m 'Add awesome feature') - Push to the Branch (
git push origin feature/awesome-feature) - Open a Pull Request
⚠️ License
lkmod-bme280 is licenced under the MIT License. See the LICENSE for
more information.