Summary of Classic LED 7-Segment Displays using PIC16F887
This article details a project reviving vintage LED 7-segment displays, specifically the HP 5082-7414 and an unknown 2-digit red model, for use in wristwatches and desk clocks. The author created custom Eagle symbols and PCB footprints (DIP 12) for these common cathode displays. The project utilizes a PIC16F887 microcontroller to drive the bright, sunlight-viewable red LEDs, offering a classic aesthetic that modern LCDs lack despite higher power consumption.
Parts used in the Classic LED 7-Segment Clock Project:
- HP 5082-7414 4-digit Red LED 7-Segment display
- Unknown maker 2-digit Red LED 7-Segment display
- PIC16F887 microcontroller
- Eagle 5.4.0 software
- DIP 12 PCB footprint
- Vintage calculator or watch casing components
Just recently I have been addicted to old LED displays as they are small and bright and I love the classic look. We can see them in vintage calculators and vintage led watches. However these displays consume significant amount of power, so they are not used in watches and calculators anymore. As they are replaced by LCD, these LED 7-Segment displays are not in production anymore and difficult to obtain.
Now, I have 2 models of the classic LED 7-Segment as shown in the picture below: HP 5082-7414 from HP is on the left. It’s a 4-digit Red LED 7-Segment very nice for wristwatch. The one on the right is an 2-digit Red LED 7-Segment from an unknown maker. It can be used in a wristwatch too (with a little bit bigger case).
Based on my inspection, I have made symbols for these displays with Eagle 5.4.0 free version. The displays are common cathode and the symbols are below
The PCB footprints are as the following (DIP 12)
I have made simple clocks using these displays and PIC16F887. The real thing looks much better than the photo. The displays are bright red and sun light viewable. Very COOL!!! They are on my computer desk and I love to see them very often.
For more detail: Classic LED 7-Segment Displays using PIC16F887
- Why are LED 7-segment displays no longer used in watches?
They consume a significant amount of power compared to modern LCDs. - Are these classic LED displays still in production?
No, they have been replaced by LCD technology and are difficult to obtain. - What type of LED displays were used in this project?
The project uses common cathode 4-digit and 2-digit red LED 7-segment displays. - Which microcontroller drives the clock circuit?
The PIC16F887 microcontroller is used to create simple clocks with these displays. - What software was used to design the symbols and footprints?
The author used Eagle 5.4.0 free version to make symbols and PCB footprints. - Can these displays be viewed in sunlight?
Yes, the real displays are bright red and sun light viewable. - What package type is the PCB footprint designed for?
The PCB footprints are designed as DIP 12 packages. - How does the physical appearance compare to the photos?
The real thing looks much better than the photo provided in the article.
