Yummy LED displays are yummy

I was planning on making a LED display face for the Chronoduino at some point and i’ve always liked the old-skool miniature “bubble” displays, so i did a little digging through eBay…

Dug up some neat little retro HP and Siemens (Litronix) 7-segment and starburst displays, bought them and two of the packages arrived today (a few hours before the TI kit from the previous post). First up, there’s the HP 5082-7433 7-segment display (data sheet here). This particular model comes in red epoxy 12-pin DIP packages of 3 digits (they were originally made for handheld calculators, hence – threesomes).

It’s a “dumb” common cathode display, meaning the pinout gives you access to interconnected segment anodes (7 + decimal point) of all the digits and common cathodes for digits 1, 2 and 3. That’s 7+8+3=11 pins, leaving one not connected. I’ve managed to break a pin on one of the displays while pulling it out of the breadboard. Of course, i did not break the N/C pin, but third digit’s cathode. Not a problem, there’s more where that came from:

Yeah. I could only buy them in batches of 30, so… I got 30. They were cheap. And then i got 17 on top of the 30, because i’ve overpaid the shipping and the seller was honest enough to tell me so and add a fistful of displays extra. Not sure what i’m going to do with all of those…

I’ve also got 6 of these Siemens DL2416T (actually Litronix – Siemens bought them at some point in the 80s) units. They were much pricier than the HPs, and for a good reason (data sheet here).

They’re 4-character 16-segment starburst alphanumeric displays with braaainnnzzz in them. The package is 18-pin DIP and they’re considerably larger than the HPs. Probably too big for a watch, in fact.

Being smart displays, they don’t require outside logic to drive individual segments – you can simply tell them what to display and where. They have their own ROM, RAM and multiplexer. They support cursor loading and display blanking, of which the latter is particularly useful (to me) as it can be used with PWM for brightness control. Control is via 7 data input lines, used to pick a character you want to display, two digit select lines, a write pin and a clear pin. Data entry can be asynchronous and completely random.

Haven’t tried them out yet, but i did hook two HP 5082-7433’s to an Arduino. It was a quick and dirty multiplexing job via a single 74HC595 shift register (the register was controlling the segments, while the digit cathodes were driven directly by the Arduino), so please pardon the horribly uneven brightness. I didn’t use any current limiting resistors, as the display’s current draw is pretty tiny at 5V anyways.

Here’s an angled shot. Visibility isn’t that bad, despite the bulbous epoxy lenses. I think this might actually work nicely in a watch or something similar.

Finally, here’s a video. I’ll try the DL2416T’s tomorrow (hopefully).

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8 Responses to “Yummy LED displays are yummy”

  1. nave.notnilc 11/08/2011 at 20:08 #

    whoa, neat displays. any tips on finding sources? may I ask what you paid for them?

    • orcinus 18/08/2011 at 02:19 #

      The HP 5082-7433 were something like $30-35 for a lot of 30.
      The DL2416T is much pricier… $30ish for two, i think.

      Both are off eBay. Just search for the model numbers, something’s bound to pop-up :)

  2. Arpad Baranyi 20/07/2012 at 15:15 #

    Hello,

    do you have yet from the HP 5082-7433 some pcs? If yes, how much would it cost 10pcs incl. shipping to Hungary (Europe)? I would pay of course in advance via Paypal.
    I am looking forward to your soonest reply.
    regards
    Arpad

    • orcinus 19/08/2012 at 23:12 #

      Hey, sorry for not replying earlier.
      I’m away from home right now (working vacation) but i do have some extras, yeah. I’ll let you know when i’m back.

  3. Paul 17/08/2012 at 09:01 #

    I found some of these displays on ebay @ 5 euro for 6 of them. Still waiting for them to arive. The dl2416 is really a nice display. The expesive ones are the hewlett packard dl2416, but you can get cheaper DL2416T from siemens/litronix. Under $10 on ebay.
    dit you manage to get the dl2416 working.
    Btw there are also dl1414, dl1416 and dl3422 (a 22-segment display)
    Nice job!

  4. Jim M 13/09/2014 at 09:09 #

    Would you be willing to sell a few of the HP 5082-7433? I built a circuit in 1981 with them I’m still using and could use a couple more.

    Thanks,
    –Jim

    • orcinus 14/09/2014 at 02:59 #

      I keep planning on using them for a project i keep delaying (due to lack of free time). But i think i’ve got more than enough for that, so – sure.

      Except i’m about to leave for a business trip, so it’ll have to wait till i’m back.

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