Attach any I2C clients (thermo sensor, AD converter, display, relay driver, ...) to your PC via USB ... quick, easy and cheap! Drivers for Linux, Windows and MacOS available.
The i2c-tiny-usb project is an open source/open hardware project. The goal of i2c-tiny-usb is to provide a cheap generic i2c interface to be attached to the USB. A USB solution has several advantages incl. the built-in power supply and a more future proof interface. Furthermore no cpu intense bitbanging is required on the host side. This USB solution even requires less parts than some printer port solutions.
I2C-Mega-USB is a compatible clone of Till Harbaum’s i2c-tiny-usb. The firmware has no software in common with Till’s implementation but is compatible with the i2c-tiny-usb driver found in the mainline Linux kernel. As a result it will work out of the box without requiring any special software on the host computer. I2C-Mega-USB utilizes ATmega32U4 with hardware I2C and USB, which should be better than the original bitbang I2C and software USB.
This setup uses ATmega32U4 Leonardo
and packaged into waterproof box and wires routed via cable glands for marine use.
With i2c sensor connected:
Download firmware:
wget https://github.com/bareboat-necessities/bbn-i2c-over-usb/releases/download/v1.0.0/I2CUSB.hex
Hold reset button while pluggin your Leonardo ATmega32U4 into USB until 3 yellow lights flash to enter bootloader mode.
avrdude -p m32u4 -c avr109 -P /dev/ttyACM0 -U flash:w:./I2CUSB.hex
- Install avr-gcc compiler toolchain and avrdude. On Debian:
sudo apt-get update
sudo apt-get -y install gcc-avr binutils-avr avrdude avr-libc i2c-tools
- Clone this repo:
git clone https://github.com/bareboat-necessities/bbn-i2c-over-usb
- Fetch the libraries:
cd bbn-i2c-over-usb; git submodule update --init --recursive
- Build the firmware:
make
I2CUSB.hex is the firmware file you flash with avrdude.
Note that the i2c_dev kernel module needs to be loaded before using any of the
i2c-tools utilities.
$ i2cdetect -l
...
i2c-13 i2c i2c-tiny-usb at bus 003 device 002 I2C adapter
$ i2cdetect -y 13
Maybe it can work on OpenWrt (not tested)
https://gist.github.com/karantir/c3b123a63696a895cc9dad32168fe690
- I2C-Mega-USB [https://github.com/kasbert/I2C-Mega-USB]
- i2c-tiny-usb. [https://github.com/harbaum/I2C-Tiny-USB]
- LUFA - The Lightweight USB Framework for AVRs [https://github.com/abcminiuser/lufa/]
- Arduino Core Two Wire Interface [https://github.com/arduino/ArduinoCore-avr/blob/master/libraries/Wire/src/utility/twi.c]
- i2c-star [https://github.com/daniel-thompson/i2c-star]
- rp2040-i2c-interface [https://github.com/Nicolai-Electronics/rp2040-i2c-interface]