Wanted: *very small* displays, 7 segment and alphanumeric. - Page 1
Forum section: electronics / general

author: Mads Aggerholm
author_rank: Newbie
timestamp: November 01, 2012, 08:50:49 pm
content: Hello Sirs,I am new to this forum, so please inform me if there is unwritten rules I might violate.Now, I am searching high and low for some very small, preferable single digit displays, not more than 3, max. 4 millimeters.7-segment and alphanumeric. Different colored ones would be very nice too.I know they exist (or have existed), because my father had two pieces once, and approximately a year ago I saw one on eBay that was 1 millimeter (!!) high!For the curious among you, I need them to make a scoreboard for a race track.I have already made "The worlds smallest race-track":And now I aim to make one more, at half the size and with a bridge!This time I´d like to include a timer to count the seconds (and 1/100 seconds) for the round. That'll be a lot of numbers, and I want to keep the size of the scoreboards as small as possible to fit the rest.Can anyone in here help me on this one?Sincerely/Best regardsMads Aggerholmwww.scandione.com

author: poptones
author_rank: Frequent Contributor
timestamp: November 01, 2012, 11:25:15 pm
content: Pretty cool. Do the cars have motors or are they pulled along on belts?If I might offer a suggestion: 7 segment displays are usually just arrays of leds. Why not use 7 small LEDs mounted under the table along with 7 optical fibers illuminating seven small slits? You could make it any size or dimension you want, even making a "pole."

author: andyturk
author_rank: Frequent Contributor
timestamp: November 02, 2012, 12:46:06 am
content: It's not 7-segment, but it's certainly tiny:http://adafruit.com/products/661Adafruit sells the breakout boards, but I'm sure you can source the raw display somewhere.Try this one for color:http://adafruit.com/products/684

author: Psi
author_rank: Super Contributor
timestamp: November 02, 2012, 12:51:06 am
content: The best option is probably a tiny OLED graphic display, you can get those really tiny.Edit: I was beaten to it, that's what andyturk just posted above.

author: cidcorp
author_rank: Unknown
timestamp: November 02, 2012, 04:21:48 am
content: Wow, I've been looking for a display small enough to make a small Automobile Rear-view Mirror Compass/Thermometer and this will do excellent, but I have one concern. How do these displays function in low temps, I haven't dug too deep in the technical docs but doesn't anyone know off hand. I'm not concerned with response of the display in low temps just it's ability to function in some capacity (I live in cold climate).I'm glad I stumbled over this thread. Thanks all who provided the links.ChrisToronto, Canada

author: Mads Aggerholm
author_rank: Newbie
timestamp: November 02, 2012, 05:41:43 am
content: Thanks for the replies, everybody.Quote from: poptones on November 01, 2012, 11:25:15 pmThank you. No, even if I had a motor small enough, the cars are too light to make a sufficient pressure on the surface to make them run. Under the tracks I've two chains and two motors from LEGO, that pull the cars using a small stick attached to the chain. It was important that the cars could fall off if the velocity became too high, otherwise it would not be a challenge to win the race; Everyone could just give'm full throttleQuote from: poptones on November 01, 2012, 11:25:15 pmI have given this a thought, but that sure would need a lot of optical fiber! 7 x 2 x 2 just to count the rounds, and for the timer with four digits (00:00 sec. if 1/100 second should be present) would be 7 x 4 x 2. That'll be 84 fibers!But thanks for the suggestion. Maybe a larger display under the track, that is transmitted to a tiny screen using a small camera...? That would be "to cross the stream to get water", though.Quote from: andyturk on November 02, 2012, 12:46:06 amThanks. This is worth a thought. I'm not very familiar with Arduino, but this could be a chance to do something about it.It also opens up for some possibilities to make some more graphic expressions. I.e. a false start, when a car wins the race, etc.Thanks again everyone!Sincerely/Best regardsMads Aggerholm

author: kripton2035
author_rank: Super Contributor
timestamp: November 02, 2012, 07:18:57 am
content: search for hcms2905they exists in a 4digits x 0,15" height that's 4mmand different led colors

author: jeroen74
author_rank: Frequent Contributor
timestamp: November 02, 2012, 11:55:46 am
content: And those modules are hideously expensive and need boatloads of wires to connect, as they have a parallel interface. 7 or 8 data lines, read/write, chipselect, several address lines.Avago also carry a few 5x5 modules of this kind that run on 3V3 and have a SPI interface. They do not come with a built-in character generator though.If you really need small digits, look up the DL1414 which you can find surplus or used. Or the Siemens DL340M.http://www.decadecounter.com/vta/tubepage.php?item=33&user=0

author: kripton2035
author_rank: Super Contributor
timestamp: November 02, 2012, 12:22:49 pm
content: I totally agree that these hdsp modules are very expensives !but you can get some lot on ebay with nice prices from time to timeI bought some like that some times ago. $5 the module...

author: jeroen74
author_rank: Frequent Contributor
timestamp: November 02, 2012, 12:29:07 pm
content: About a year ago my last employer had their yearly clear out of all the offices and I found a tube with 9 pieces of spanking brand new DL2416 modules in the binAnd I found more stuff like a barely used Atmel STK500 and AVRISPMKii, a Keil ULINK, a ST JTAG programmer and a Microchip ProMate II... I bought it all for €1