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7-segment LED from Radio Shack
Posted: Sat Dec 03, 2011 3:01 pm
by clair
I always want to see letter and numbers, in other words, output; so I snatched up this 7-segment LED display at Radio Shack only to find out that apparently no one in the world but me has ever used one with an Arduino. All the ones in Arduino projects have the pins neatly at the top and bottom. So much for that. I spent hours searching for how to translate the project code I was using to match the one I had. Finally, working with a datasheet from National Semiconductor I managed to do it. (BTW, I am brand new at all this stuff -- 4 days only.)
So, I thought I post an image of the Radio Shack LED, RS part number 276-075; National Semiconductor part ELS-321HDB/A. maybe it will help some other hapless newbie like myself.

- Pin diagram of National Seminconductor 7-seg LED (Radio Shack).
- ELS-321HDB_A-pins.gif (11.14 KiB) Viewed 5474 times
Re: 7-segment LED from Radio Shack
Posted: Sun Dec 04, 2011 1:33 am
by thefatmoop
Output over rs232 is pretty good too but requires a computer. I often use an LCD similar to this one
http://www.adafruit.com/products/198 Pretty easy to wire up and the library makes it just as easy as the serial.print commands.
If you want to save some pins on the arduino with that 7 segment you could look into a shift register
https://www.adafruit.com/products/457
Re: 7-segment LED from Radio Shack
Posted: Sun Dec 04, 2011 6:53 am
by clair
Yes -- I just got some from adafruit, and am investigating how they work right now. In doing that, I found this project
http://www.sqlskills.com/blogs/paulsele ... plays.aspx
which, from his diagrams, I deduced was using four of the same 7-segment LED. He has some nice images.
As I said, I'm only 4 days, well, 5 now, into be the proud owner of an Arduino, so I've much to learn. In this wholly new field I've decided to take one component and run it to ground as it were. So, I've decided on 7-segment displays as my first subject -- and of course that leads to shift registers, and who knows what else!
Re: 7-segment LED from Radio Shack
Posted: Sun Dec 04, 2011 7:04 am
by clair
Oops -
forgot to post a link to the code I used -- it's originally from Hacktronics
http://www.hacktronics.com/Tutorials/ar ... t-led.html
and my version, commented and with an image at the bottom, is here:
http://www.clairdunn.com/personal/ardui ... nt-led.htm
Re: 7-segment LED from Radio Shack
Posted: Mon Oct 28, 2013 5:06 pm
by rionwulfe
Thank you so much for posting this, Clair. It helped me.