To some there is the allure of older technology - such as nixie tubes, vacuum-fluorescent displays and old LEDs that can't be ignored... and when they turn up again the first thing to try is getting them working with an Arduino for retro-fun and reminiscing. Paul Huinink feels the same way and has spent some time to document how to use Hewlett-Packard HDSP2000 alphanumeric display units with an Arduino.
Originally released in 1975, the HDSP2000 were designed for almost any use and were popular for outdoor devices, as their Gallium-Phosphide LEDs were readable in direct sunlight. Driving them requries some constant-current sinking drivers and in his example Paul has used UDN2981s for the purpose. The circuitry isn't that complex, and provides us with the following example:
So if you come across some of these displays, or just enjoy seeing older technology at work - visit Paul's website for complete instructions. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're interested in text output for your Arduino projects, but don't have any vintage displays - save time and move forward with the Freetronics LCD & Keypad shield which contains a bright 16x2 character LCD and five buttons that can be read from only one analogue input pin: