Glowing Eyes: Need help finding 64 pin connector for Halloween project - Page 1
Forum section: electronics / projects

author: Emrys
author_rank: Newbie
timestamp: October 11, 2016, 03:05:12 am
content: Hi all - first post on here, please forgive me if you don't think this post belongs in this topicA little background first -- I saw on Youtube a pretty cool DIY project to make some glowing eyes to put up into your window for Halloween. They used toilet paper tubes and glowsticks, and I saw room for improvement. (there's a bunch of vids on the topic, here's one that shows how to make them their way:)After seeing this I thought, "Man, that would be so much better with LEDs!" So anyways, my improved version includes a window-sized piece of cardboard, lots of eye cutouts, 4x SN74HC244, 2x SN74HC595, and a launchpad to control everything.After a couple weeks of after-work-soldering/wiring, I had the ugliest board I've ever seen, but it worked perfectly. I could run 16 sets of 2 LEDs from the launchpad.I'm now working on making a PCB version of this so I can clean it up (a lot), but I'm having a hard time selecting a connector. I need to connect 32 LEDs to a board, meaning I need 64 connections (unless I decide to solder all the grounds together and make it 33). Right now I'm using Cat5e wires to connect all the LEDs, which is kind of a mess, but at least they stay bundled together and I can follow the colors to find specific LEDs when I need to -- and those are soldered straight to the board.tl dr:I would like to find a cheap connector (or connectors) that can handle 64 connections (or some large subset of that - 32, 16, 8...), each running only ~15mA at 5V max. I'd love to find something like a PCB mount punch down block, but I can't seem to find anything in this size range.Any ideas are welcome. And for those that want pics,

author: grifftech
author_rank: Frequent Contributor
timestamp: October 11, 2016, 02:34:23 pm
content: Use a card edge connector like this onehttps://www.amazon.com/PCI-Express-Flexible-Extender-Extension-Computer/dp/B01HM5F046/ref=sr_1_1?ie=UTF8&qid=1476196387&sr=8-1&keywords=video+card+extender] https://www.amazon.com/PCI-Express-Flexible-Extender-Extension-Computer/dp/B01HM5F046/ref=sr_1_1?ie=UTF8&qid=1476196387&sr=8-1&keywords=video+card+extender

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 11, 2016, 02:37:11 pm
content: IDC header ( 64 or 2x34), slit the ribbon for connection to each LED

author: mariush
author_rank: Super Contributor
timestamp: October 11, 2016, 03:26:31 pm
content: Use an IDE cable and you have 40 pins.But seriously, put a bunch of led drivers on the board with the leds .. you can get led drivers with up to 48 separate channels and they behave like your shift registers so you just shift in a few bytes and hit the latch pin and bam, all channels update their state at once turning on or off depending on the bytes you shifted.So you'd only need 2-3 wires for data and a couple for power, so you could use a plain cat5e cable or an IDC header.

author: Emrys
author_rank: Newbie
timestamp: October 12, 2016, 02:28:19 am
content: Thanks for the suggestions guys. I hadn't thought of making the edge of my PCB into a connector like a PCI card - seems interesting.Not sure how using a different method of LED driving will eliminate the need for lots of wires and a connector - note that the LEDs are on a piece of cardboard in my window, and the PCB is a separate entity.I will probably go with the IDC header - I think that's the cheapest and cleanest solution without a lot of extra work. I might even make 2 boards for that - one to just interface to the cardboard panel and the other for the actual circuitry, then connect the two with ribbon cables.Thanks again guys