Vacuum Fluorescent Display Modules (VFD) are devices that use heated filaments to cause phosphor coated plates to emit light within a vacuum. The viewing area ranges in sizes from 46.54 mm x 7.65 mm to 306.95 mm x 25.35 mm. The available display types are character, graphic, 7 and 14 segment. These display modules can have interfaces of I2C, parallel, RS-422, serial, SPI, TTL/CMOS, and USB.