Moving signs are a common enough sight today but off-the-shelf units are invariably expensive and somewhat inflexible. The six-character module described in this article can be cascaded up to 16 modules long and has a character set that can be customised to suit your application.The dot matrix moving sign module presented here has a six character display area. A maximum of 16 of these modules can be cascaded together to produce a 96-character display. The PCB layout for the module can accommodate 5×7-Matrix displays with a distance between the rows of pins of 33.0 mm (30 mm character height) but larger or smaller displays may also be fitted by using adapter boards, if the LED matrix is electrically compatible, of course.The big advantage of building this moving sign yourself is that the cost of the finished article is much less than that of a ready-built unit. Most of the ICs used in the design are widely available and relatively cheap. The passive components are all standard and an AT89C2051 with Flash-memory is not the most expensive microcontroller. The main item from a cost point of view is the type of LED matrix displays that are used.