Example for access to a MAXIM 6958B chip
4-Digit, 9-Segment LED Display Drivers with Keyscan communication via IIC

The example supports IOWarriors 24, 40 and 56.
You need an IOWarrior with a MAXIM 6958B and up to four 7 segment displays wired on the breadboard area.

Best get the datasheet for the MAX6958B as PDF from http://www.maxim-ic.com

The example tests the MAX6958B in digit mode. This means it can only show hex digits.
Write hex digits to the device or control the brightness of the displays.
"Reset" sets the displays to "0000" wheras "Test" activates all segments including the decimal point.