bosone Posted May 19, 2004 Report Posted May 19, 2004 i will begin the construction of the sequencer soon.but i have a doubt (or a dumb question..) ... i dig into the site but i didn find the answer...how are the two 2x40 LCD connected to the core?the core pinnings is for one LDC... Quote
moebius Posted May 19, 2004 Report Posted May 19, 2004 Check LCD module page.There's diagram to connect two character displays. All (control and data) lines, but ENABLE line are shared by two displays. ENABLE to second display is taken from J10 - RC pin.Bye, Moebius Quote
Echopraxia Posted September 18, 2007 Report Posted September 18, 2007 Newbie question. If I use a 16 pin IDC connector for the core board connection,would I take 2X 16 pin cables minus the extra enable line and crimp both cables to the single IDC connector?One more question. Where you can solder dil/sil headers on the lcd side of the cable is it possible to label data wires and switch there location on an IDC connector so you can have an IDC on ends of both LCD displays? Also I am going to get in on the next bulk order for LCDs that is coming up real soon. Quote
nebula Posted September 19, 2007 Report Posted September 19, 2007 Newbie question. If I use a 16 pin IDC connector for the core board connection,would I take 2X 16 pin cables minus the extra enable line and crimp both cables to the single IDC connector?I wouldn't try to squeeze 2 cables into a single IDC connector. Maybe others have had luck with that, but I'd be dubious about getting a good connection.If you really want to go IDC, you could put a header with really long legs on the CORE, so it sticks out the bottom of the board. Then you could put an IDC connector on each side of the board.One more question. Where you can solder dil/sil headers on the lcd side of the cable is it possible to label data wires and switch there location on an IDC connector so you can have an IDC on ends of both LCD displays?Yes, it's possible ... but it is probably more trouble than it's worth. Ribbon cables work nicely for IDC connectors because all the wires stick together, and you only need to lay down the ribbon and squeeze. Trying to lay a bunch of individual wires would probably be a challenge!What you're trying to do here is change the pinout of the LCD pins from the CORE so they match your display. At the same time you're trying to connect 2 LCDs to one CORE. Personally, I'd probably make a little adapter on a piece of prototyping board... like "pad-per-hole" board, like this:solder down a 3 headers: 1 to connect to your core, and 1 for each LCD. Then turn the board over and solder some little wires to connect the 3 headers appropriately. You could then use straight-through ribbon cables with IDC connectors on each end. This little new board would connect to your CORE and your two LCDs.But ... that takes up space, and it would be time-consuming. My interconnect method of choice is the Molex crimp method. The connectors and pins look like this:... If you're careful you can crimp two wires into a pin. You can use ribbon cable, but I prefer to just run individual strands, similar to the way you typically see the inside of analog synths wired up. Also I am going to get in on the next bulk order for LCDs that is coming up real soon.Yay! The LCDs are pretty good. Quote
ris8_allo_zen0 Posted September 19, 2007 Report Posted September 19, 2007 If you really want to go IDC, you could put a header with really long legs on the CORE, so it sticks out the bottom of the board. Then you could put an IDC connector on each side of the board.I also thought about this, but it wouldn't work because the pin mapping would be inverted (i.e. each pair swapped).To connect two LCDs, my solution is to crimp two IDC connectors to the same ribbon cable (just like the IDE or floppy ribbon cables), then cut the wire corresponding to "Enable" just after the first connector. In this picture you can see that connector. The blue wire is the second Enable.You also see the connector at CORE side with all the wires manually crimped... I'm not much proud of it, but at the end it works!Greetings, RAZ Quote
nebula Posted September 19, 2007 Report Posted September 19, 2007 I also thought about this, but it wouldn't work because the pin mapping would be inverted (i.e. each pair swapped).But does that really matter when you've just got flying leads on the other end anyway? Quote
stryd_one Posted September 19, 2007 Report Posted September 19, 2007 Uhm ... crimp the IDC connectors to either end of the cable and one in the middle... L I-----------------------I-----------------------I L C D-----------------------D-----------------------D C D C--------------------X--C-----------------------C D Cut the 2nd enable line at 'X' and peel it off and connect to the coreLCD's go in either end so they're not connected serially to the coreI think tha's what ris8 did? Quote
nebula Posted September 19, 2007 Report Posted September 19, 2007 Uhm ... crimp the IDC connectors to either end of the cable and one in the middle... L I-----------------------I-----------------------I L C D-----------------------D-----------------------D C D C--------------------X--C-----------------------C D Cut the 2nd enable line at 'X' and peel it off and connect to the coreLCD's go in either end so they're not connected serially to the coreI think tha's what ris8 did?Sorry ... didn't finish my last post ... you're right. That makes total sense. Quote
ris8_allo_zen0 Posted September 19, 2007 Report Posted September 19, 2007 I wrote a post about two hours ago but forgot to click "Post" :PBut does that really matter when you've just got flying leads on the other end anyway?Sorry, it was my fault. I'd say: it works, but pay attention that the wires are swapped in pairs.Uhm ... crimp the IDC connectors to either end of the cable and one in the middle... L I-----------------------I-----------------------I L C D-----------------------D-----------------------D C D C--------------------X--C-----------------------C D Cut the 2nd enable line at 'X' and peel it off and connect to the coreLCD's go in either end so they're not connected serially to the coreI think tha's what ris8 did?That's exactly what I did! See this picture: you see the middle IDC connector and the one for the Core, and the blue wire which is the second Enable line.(don't care about the heatshrink near the connector: it was a mistake)RAZ Quote
Echopraxia Posted September 19, 2007 Report Posted September 19, 2007 Thankyou for all your suggestions. Stryd_one, from your diagram it looks like you take one long ribbon cable and slide an idc connector down to the middle of the cable and when you crimp this down you have two ends (one for each LCD) with the middle IDC connector going to the core right? Then you cut the enable line for 2nd LCD right by the core connection to run it to J10 RC. I do have one more question about pinouts for IDC connectors. I read building a midibox LCD cable by Jim Henry and saw the pin 1 indicator for the IDC connector which is a triangle. My question is which is pin 2 and so on on the connector. There are 2 rows of eight headers. Is it pin 1 pin 2 Pin 3 pin 4 Pin 5 pin 6 pin 7 pin 8 ect....?Or is it pin 1 pin 9 pin 2 pin 10 pin 3 pin 11 pin 4 pin 12 ect...? Quote
nebula Posted September 20, 2007 Report Posted September 20, 2007 You only need to do it once, so make sure you follow each individual conductor to ensure it's going to the right place on the LCD.Incidentally, if you are planning to use the Optrex 40x2 LCDs from the forthcoming group buy, there is an accurate graphic of the pinout on this 1-page pdf drawing:http://www.optrex.com/SiteImages/PartList/DRAWING/DMC-40202AZN_drawing.pdfIf you plan to mount your LCD to a front panel, remember that you may prefer to put your header on the BACK of the LCD - in which case the pins would obviously be backwards. Quote
ultra Posted September 20, 2007 Report Posted September 20, 2007 i made the little sub-board that has straight connections to idc headers and then rewire in between. it's more junk in the box but it made it easy to troubleshoot if there's a problem. Quote
Echopraxia Posted September 20, 2007 Report Posted September 20, 2007 Thanks for the pinout nebula. In the Optrex 40x2 LCD's diagram I see all the way to the left pins 1-14 but 15 and 16 are on the right side of the display. I am looking at TK's diagram and these need to be hooked up aswell. If that is the case then I would assume to just use seperated/singal wires for each pin 15 and 16 and not try to marry them with the IDC. I am tired..... One more thing nebula. When you took the video of testing the LCDs, It looked like you were disconnecting and reconnecting with a IDC connector correct? How were you using/connecting pins 15 and 16? Again very tired... Hooking up the core and LCD and testing it out before the other modules (i.e. dins,dout,IIC) seems like the best idea before going any futher. Quote
nebula Posted September 20, 2007 Report Posted September 20, 2007 The bulk buy is starting tonight. You ask a good question so I'll mention my test method in the Bulk Buy post. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.