I am looking for what I'm sure is fairly trivial or basic guidance on soldering up some components for an Arduino project.
My project is a working model football scoreboard which will involve 16 7-segment LED's, some two-digit, some single-digit. I'll be driving them through two cascaded 7221's, and I've already wired up a couple of samples on a breadboard and have the sketches working the way I need.
I'm trying to "componentize" my project, so the help I need is in the basic wireup of the various LED's to a final piece of perfboard with headers. My intent is to simplify the wireup of my project by connecting the pins of the LED to a header, and "standardize" the pinouts on the header, eg pins 0-9 always indicating segments A-G, DP, and digit select. I'll do the same for the segment pins of the 7221's, thus allowing me to just fabricate cables to run from the LED's to the drivers.
In my head, as an example based on one of my two-digit LED's, I envision the "assembly" being as simple as soldering the LED to the perfboard, then soldering a dual-row 18-pin right-angled header to one edge of the perfboard, then soldering wires underneath the perfboard from the pins of the LED to the header.
Is this a reasonable plan? Are there obvious problems with this that I'm just not seeing? Are there special considerations I need to keep in mind as I solder the wires from the LED to the bottom of the header? Or should the LED be mounted to an IC socket? Is there a better/smarter way to connect the wires to the header?
I'm sure this is really a very basic assembly question, but I'm new to the hardware side and soldering is something I'm still trying to get better at, and keeping it in simple chunks seems the best plan for me at this point - so I appreciate the help!
I'd use wirewrap socket strips for everything and wirewrap it all up. Lot easier to make changes, fix mistakes, etc. Quicker too.
This place has all you need. Use Island of Holes perf board, tack down the socket strips at the ends and one in the middle, then have at it. http://www.king-cart.com/phoenixent/category=SOCKETS+WIRE+WRAP+DIP+%2526+SIP
I use the gold wirewrap too myself.
Thanks, LarryD, but the only problem there is they are a UK supplier and I'm here in the US Midwest Thinking the shipping costs/times might put them at a disadvantage.
CrossRoads:
I'd use wirewrap socket strips for everything and wirewrap it all up. Lot easier to make changes, fix mistakes, etc. Quicker too.
This place has all you need. Use Island of Holes perf board, tack down the socket strips at the ends and one in the middle, then have at it. Phoenix Enterprises category - SOCKETS WIRE WRAP DIP & SIP
I use the gold wirewrap too myself.
In looking through the items on their site, I wasn't immediately noticing any right-angled dual-layer wire-wrap headers - just the regular soldered variety. Was I just overlooking them or am I looking for a ghost for some reason?
Would you happen to have a link for a good primer on wire-wrapping? I've read about it, but now that I'm seriously considering doing this for my project rather than soldering, I thought perhaps you would have a good reference for a newb. Many thanks.
I finally took some time to dig further through that parts/supplies site and tried to make some selections for my project. I'd like to run some particulars of my project and ask if what I've picked here is right or wrong before I plunk down the cash.
First, the two-digit LED's I already have are Lumex LDD-C814RI, the data sheet for which can be found here. My first intent was to purchase wire-wrap sockets for these LED's, but I was not able to find 18-pin sockets on a .866" width; I saw some sockets with a .9" spacing, and thought that difference of .03 would not matter, but I wasn't sure. Would such a socket work? I've not found any sockets with a specific hole distance of .866" (corresponding with the pin distance on the two rows on the LED's).
If the .9" wire-wrap socket is not suitable, is there anything wrong with selecting two "single" SIP-type wire-wrap sockets and just using them in parallel? Such as this SIP socket that I could just break into 9-pin segments?
I also could not find any right-angled dual-layer wire-wrap headers, so I may have to settle for regular (straight) headers and perhaps look to fashion 90-degree cables(?). I was looking at this part for the headers.
Also, one last question. If I'm using the solder merely to tack down the sockets and LED's, does that imply that the perfboard I select should only have conductive material on one side? That is, if I place a dab of solder on either end of a socket to secure it to the board, I might inadvertently create a connection if the solder touches the pads across adjacent holes...or am I missing something entirely?
The biggest part of this first purchase is the wire-wrap tool for $31 and a couple of spools of cable for about $8 each, so the risk isn't that big a deal, but I was hoping to get a sanity check on what I'm buying.
Thanks in advance for the help. It's very much appreciated.
