Roger430 managed to get talk to a segmented LCD via a PCF8566 LCD display driver through I2C. He uses a Launchpad with a Value Line “G” Series chip to talk to it. The PCF8566 is a peripheral device which interfaces to almost any Liquid Crystal Display (LCD) with low multiplex rates. It generates drive signals for any static or multiplexed LCD containing up to four backplanes and up to 24 segments and can easily be cascaded for larger LCD applications.

The toughest part was trying to figure out the configuration of the Raw LCD display. This one happened to have 4 back planes and used only 2 pins for each character for a total of 20 pins. It has a few graphics and a low battery indicator. It also has a small 7 segment character in the upper right hand corner as seen in the photo. The PCF8566 plays nicely with the MSP420G2231 and works very well with 3.3v.

I managed to cobble together a workable temperature display of the internal MSP430 temperature sensor. I used the small character in the upper right hand corner of the display as a degree symbol (actually the character 0). I used a table lookup for the characters 0 – 9. Right now it only displays the temp in two digits. I need to display 3 digits here in Texas – temps last summer were mostly in the 100’s.

His schematics and code can be found in his Forum thread.