This is the Adafruit thermal printer, whose Arduino library is published here: http://www.ladyada.net/products/thermalprinter/. This is a basic port to mbed that needs proper testing. The printBitmap function is not ported yet.
This is the Adafruit thermal receipt printer library ported hastily to mbed.
printBitmap is not yet ported. TBD
It needs testing properly. TBD