Raspberry Pi LCD temperature display with big font

I've already hooked an HD44780 LCD screen to my Raspberry Pi and displayed the temperature from a Dallas DS18B20 temperature sensor, but using the built-in font on the LCD screen was unsatisfactory. It was too small. I have also hooked up a 32 x 8 LED dot matrix and that was good, but a bit over the top for my living room. I wanted a bigger font for the numbers on the LCD display. I Googled and Googled until I found this Perl module by Joshua Small. It took me a while to get it working (the example in the synopsis is littered with typos and I don't know much Perl). It also seemed a bit unstable with my LCD at least, often filling the screen with garbage so I wanted to get it to work with the WiringPi library and also because I'm more familiar with C and the Arduino Wiring library. So I set out to convert the Perl module and example to C. This took me a while too, and whilst the results may not be particularly elegant, they get the job done and I'm quite pleased that I was able to do something fairly complex all by myself if I do say so myself.

The code is on bitbucket and here's a piccy: