Usage Instructions

The TWI 7-segment display can be used with any microcontroller that has a TWI or I2C bus. It works both with 5V and 3.3V systems (note that maximum brightness is lower on 3.3V compared to 5V).

To use with an Arduino or a board compatible with the Arduino IDE, there is an Arduino library available. It is implemented using the Wire library, and should work with any Arduino.

A low-level avr-gcc library is also available, and should work on ATMega chips that have an on-board hardware TWI bus. (ATTiny chips are not supported at this time, as they do not have TWI hardware).

If your processor is not directly supported, you can interface with the chip directly using its TWI protocol.

The library is the same as used with

null display, and the two displays can be used interchangably.

Usage with Arduino

The TWI 7-segment display is directly supported in the Arduino IDE. Version 1.0 or later is required.

To use it, either download our custom IDE package, with the required library preinstalled:
Arduino IDE with Akafugu Libraries.

If you already have the Arduino IDE installed, get the package and follow the instructions in this page:
Arduino IDE with Akafugu Libraries.

Once you have the Arduino IDE and the Akafugu Libraries installed, start or re-start the IDE. You should now have a TWIDisplay submenu inside the File -> Examples menu.

Here is a small example sketch for dislaying a number counter:

Protocol Documentation

If your processor has hardware TWI/I2C, adding support for it should be easy. We recommend using theGitHub library as a reference.

Have a look at the protocol documentation here: