03 June 2016

A clock with Arduino and four HP 5082-7300 displays - 1

I needed a time display on my bedside table and I wanted it with an electronic vintage touch. So I gathered:
  • 4x HP 5082-7300 displays
  • an Arduino-like board
  • an RTC module
  • a perfboard
  • some female pin headers
  • wire, solder, tools, ...
  • a 5 Vdc source
  • an LDR
  • a couple of N.O. pushbuttons
Four HP 5082-7300 displays.
An HP 5082-7300 display is an early LED display developed before 7-segments became the de-facto standard. It includes a BCD decoder and it displays 0-9, dash and blank and a right hand side decimal point. Each segment is composed of few LED dots, so it mimicks a dot-matrix display. It works from about 4 V to 5.5 V and it drains an average of 100 mA at 5 V: that's half a Watt per display! We are talking about late 1970's technology.

So, why using these power hungry displays in 2016? Simple: to learn something new and to save old technology from the recycle bin. Moreover a modern microcontroller makes it very easy to produce a BCD sequence that represents the time of the day.