I have been developing a ceiling fan sign for the last 10 years.
To convert the ascii set characters into graphics on the rotating display, I bought a software package from www.webcatering.com/font2bmp/
It converts any windows font character into a .bmp graphic file.
I then wrote a conversion program using Liberty Basic which reads the .bmp character and outputs a machine language table that the microcontroller understands.
Since the sign has 32 vertical pixels and has a 1mm resolution, this is the easiest method. The Basic program can convert any .bmp file so CocaCola and Budweiser are just as easily displayed.