Hawkeye Posted June 16, 2012 Report Share Posted June 16, 2012 You can safely invert A and K wires for LED-backlit displays that don´t obtain logic voltage from these pins (they should not anyways). Quote Link to comment Share on other sites More sharing options...
smashtv Posted June 16, 2012 Report Share Posted June 16, 2012 yes i understand that too after re-reading the datasheet 3 times. That´s a strange switch ! (how it could be use if it accept 250VAC but the led only work with 12VDC ? it´´s only for special application ? ) It is probably for automotive use..... but UL/VDE/HSE/CE/CSA like ratings listed in AC terms so you end up with some parts like this that should say "3A 12VDC" on the side and be tested vs. a proper automotive electrical standard instead. Best regards Tim Quote Link to comment Share on other sites More sharing options...
Lamouette Posted June 20, 2012 Author Report Share Posted June 20, 2012 Hey ! What's up ! i didn't work on the SeQV4 (i'm trying to debug a shruti :rolleyes: ) But before i return on it, here is something i can do to test my screens ? just to se if the can full lit ? if i just connect an A and K on it, will i have full brightness ? Thx and Bye !!! Have a good breakfast ! Quote Link to comment Share on other sites More sharing options...
Brathering Posted June 20, 2012 Report Share Posted June 20, 2012 (edited) Brightness depends on voltage given to it. Connect 5Vdc to pin 15 (LED-Anode (+)) and 16 (LED-Kathode (-)) and see what happen! ;-) -> Measure first that it will deliver max 5.1Vdc, otherwise display-kill !!! <- Attitude can be realised with a pot later, but that have the mbseq allready in it. Edited June 20, 2012 by Brathering Quote Link to comment Share on other sites More sharing options...
Brathering Posted June 22, 2012 Report Share Posted June 22, 2012 Lamouette, are you still alive!? 1 Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted June 22, 2012 Report Share Posted June 22, 2012 He is one tough guy, no worries, in canada they arm-wrestle with bears because there are not many other neighbors around :) Quote Link to comment Share on other sites More sharing options...
Brathering Posted June 22, 2012 Report Share Posted June 22, 2012 :D hahahahaha :D Quote Link to comment Share on other sites More sharing options...
Lamouette Posted June 22, 2012 Author Report Share Posted June 22, 2012 haha :laugh: i´m not a real canadian ! But you´re right ! i will give you some news quickly, actually i try to finish the Shruthi-1. it´s close to be done ! the summer is the worst season to work as well, my flatmates always asking me to drink some beers around a campfire, near the river, at home, at night, at morning... :tongue: and the season of festival is started so my weekend are quicly full of things ! :ahappy: i also started to do some sport so it reduce the time i have to work on soldering... finnaly the winter will be nice ! :frantics: i promise i will work on the SEQ this weekend ! Quote Link to comment Share on other sites More sharing options...
Brathering Posted June 22, 2012 Report Share Posted June 22, 2012 It was just because the prequel-story about the blowing switch, time-management here is as catastrophal as yours. :-D Quote Link to comment Share on other sites More sharing options...
Lamouette Posted June 26, 2012 Author Report Share Posted June 26, 2012 breaked the fuse of the PSU.... have to wait to go shopping.... waiting again.... some news later ! :rolleyes: Quote Link to comment Share on other sites More sharing options...
Lamouette Posted July 4, 2012 Author Report Share Posted July 4, 2012 ok, i can´t wait more so i order a USB hub (self powered), like that a could work and finish the SEQV4, but i will come back to use that PSU. :devil: i give you some news when i receive it , and if my screens lights correctly ! :drool: i know i have to check if the SD card reader works cause actually, when i plug the LCP17, it nerver detect my SD card. See you asap ! Bye :ahappy: Quote Link to comment Share on other sites More sharing options...
Lamouette Posted July 21, 2012 Author Report Share Posted July 21, 2012 (edited) Hey hey hey !! After :blink: More as 1 month, i finnaly received at home my USB hub, to power my SEQV4. So i plug it, but like the beginning, my screens not lighting normaly, it is so low.... :wacko: What i could try to have a full power of brightness ? ( manly lighting :D ) Thx and bye ! ps : i'm happy cause just during this time i build a shruthi, so i could use the SEQV4 to sequence it !! :frantics: Re bye !!! :rolleyes: Edited July 21, 2012 by Lamouette Quote Link to comment Share on other sites More sharing options...
MaG2k Posted August 10, 2012 Report Share Posted August 10, 2012 Hey Lamouette... could be that i have some informations or ideas to handle your LCD-Backlightproblem. I will give you some new impulses...i also building the SEQ V4 at the moment and finished building the LPC17 Core yesterday! I Uploaded the Bootloader as discribed in the manual. Everythings seems to be fine. Today i startet to build the wiring for the LCDs. I bought two different types of 40x2 modules. I had also the problem to get a manual to the LCDs but because i had two problems. First one LCD-Type 1 had no backlight and problem two, second LCD-Type had full backlight but not controlable via trimmer on LPC17 Core-Board. Let me start with the second problem...full power backlight...reason for it was that the display had 16 PINS but only 14 were wired und the displays-PCB. But no problem look at the Backside of the Display PSB and measure were the backlights Anode and Kathode are connected to the 16 PIN-Display-Header. (at my display A and K was hooked up to PIN1 Vss and PIN2 Vdd of the Display-PinHeader). But i measured were the PINs 15 and 16 are connected to because there was a wiring on them and i found out that there ar open pads on the Backside of the LCD-PCB and some Pads that are wired with zero Ohm resistors (briges). by measuring i found out that you have to close some of these Pad-Bridges and to open others and then the backlightpower doesn't come from PIN1 and PIN2 anymore but then from PIN15 and PIN16 of the Display-Header. The other displaytype was a little differnt from that because the Backlight on the Displays PCB is wired to PIN16 and PIN15 of the Displayheader...but i had no backlight...cables were correctly made and measured. the Displays Manual said 16 is minus (kathode) and 15 is plus (anode) but after measuring i found out that the wiring is mixed up...so in reality on the Display PCB 16 was plus (anode) and 15 minus (kathode) but also on that display i found a circutry to switch that. there only to zero Ohm resistors had to be change places to two emty Pads. and the result was...now after correcting the displays backlight circutry it works! Long tex but short help for you...look at the Backside of your Display...search around the backlights connection to the display-PCB for empty Pads...measure the connections from the empty pads to PIN15 and PIN16 of the LCD-PIN-Header (via short-checker) and i think you also will find those empty pads you have to stuff and/or open and your backlightproblem will be solved! :-) To Contrasttrimmer i have to say that my second LCD-Type needs nearly the complete 5V contrast voltage to make something visible on the screen. the first one is a little more sensitv. Regards MaG2k Quote Link to comment Share on other sites More sharing options...
Lamouette Posted August 15, 2012 Author Report Share Posted August 15, 2012 Hello MaG2k and thank you for the answer ! I don't know if i understand all you explain, but i tried some things. after read the manual of the LCD i (hope) understand that the pin was inverted. (if you want check, the link are on the page 3. so i tried to invert the wire on 15 and 16, but nothing change. i understand that i have to add or remove bridge. but i don't know which part it is. i add a photo to help. between which pad i have to test, i tried, but everytime it write 1 or -1 on the multimeter screen. Do you have an idea ? Thanks, bye Quote Link to comment Share on other sites More sharing options...
orange_hand Posted August 15, 2012 Report Share Posted August 15, 2012 (edited) Hi, you want to check this out: Most of the displays are identically, especially the 2x40 as there are not some many different on the market compared to the 4x20... For further support, please post the data sheet of your display... You can search via your preferred search engine using the ID's on the back of your display. Also the shop where you bought them should have a data sheet. Cheers orange Edited August 15, 2012 by orange_hand Quote Link to comment Share on other sites More sharing options...
Lamouette Posted August 15, 2012 Author Report Share Posted August 15, 2012 (edited) Thx a lot for this schematic, i didn't find it ! Now i could check the LCD : C-51850NFQJ-LG-ACN Links for datasheets : http://www.kyocera-display.com/SiteImages/PartList/SPEC/51850ace.pdf http://www.kyocera-display.com/SiteImages/PartList/DRAWING/51850acd_drawing.pdf Edited August 15, 2012 by Lamouette Quote Link to comment Share on other sites More sharing options...
orange_hand Posted August 15, 2012 Report Share Posted August 15, 2012 Hi, according to the data sheet attached, the wiring of your LCD is exactly the same as the once I used. Please note that my mapping table is for the CORE32, not sure if the LPC17 has got exactly the same allocations on its connector. If so, you can use the mapping 1:1... Good luck :-) Cheers orange Quote Link to comment Share on other sites More sharing options...
Lamouette Posted August 16, 2012 Author Report Share Posted August 16, 2012 (edited) Hi, i changed do another ribbon with the same wiring as you, but now, when i connect it, and powered the LCP17, the led on the LCPxpresso flash one time, and nothing more, maybe my ribbon is bad, but after verifying the shcematic, my first ribbon was good. so it's not a ribon problem. i mesured the pin with my multimeter : On the LCP17 : Gnd - Pin 15 = 5V Gnd - Pin 16 = 0V On the screen : Gnd - pin 15 = 4.79V Gnd - Pin 16 = 0.11V But i don't have any backlight !! So i claim the problem is something like MaG2k said, it's a brigde or not ? but which one, i don't want to burn my screens, but bridging something wrong. Edited August 16, 2012 by Lamouette Quote Link to comment Share on other sites More sharing options...
Lamouette Posted August 17, 2012 Author Report Share Posted August 17, 2012 i just read on the documentation (Page 6) that there is a VR Reverse voltage. maybe here is a link with the Pads VR1 (Photo above), and if i connect them, it will be good no ? I just want to try the backlight : could i just connect the 0v and +5V form the lcp17 (with a 2 pins DIL on the screens socket) to the A and K on the back of the screen ? If it don't work, the problem would be on the screen. No ? Bye :) Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted August 17, 2012 Report Share Posted August 17, 2012 This could be risky, sometimes there are caps and current limiting resistors (on the LCD PCB) before the A and K, and you would be cutting them out of the circuit. Quote Link to comment Share on other sites More sharing options...
Altitude Posted August 22, 2012 Report Share Posted August 22, 2012 Lamouette, Post a pic of your ribbon cable. Like I mentioned in the PM (and worth noting here for everyone), those Optrex displays have the pins oriented on the FRONT of the LCD, if you put the header on the back and use a 1:1 pinned IDC cable, it will be miswired and you will blow the back light instantly (i did it on my first one), check the 16pin header connections with a meter for continuity between each pin of the core and the display and make sure they match up before firing it up Quote Link to comment Share on other sites More sharing options...
MaG2k Posted August 30, 2012 Report Share Posted August 30, 2012 Hi Lamouette, ist a long time ago i watched you thread...but now i saw...you didn't found bridges on your LCDs-Backside. You made a photo of your LCDs Backside but only that half were the 16 Pin-connector is. Can you photograph the other half to? Because at "orange-hand's" photos you can see some resistors and some pads of not placed components. on that side it can be that there is that what we are searching. But by the way...you asked if you coudn't connect the 5V and GND directly to the A and K of the Backlight. Hmmm...as the others told it can work but it can also be that you see yor backlight for a short moment and that was the last time the was lite. But i must say that i did it right that way...cause a use 2 2x40LCDs with only 14 PIN connectors. There the A and K is not connected so you have to make own wires. And that wires run directly to PIN 1 and 2 of the 16 PIN connector from the Corebord. The Bcklight is making light...it works but i have to say the the displays get a little hot for my opinon so it is only for testing issues in use in that constelation. Later i will connect the A and K PINs to 15 and 16 of the Coreboard cause the you have the possibily to dimm the light by using Pot P1 (or P2)...(one is contrast and one backlightintensity). I hope that you dont got bad Displays with defectiv backlight. as i red you had testet a lot. what you can do is to use a powersupply were you can control the current limit. go to 3v and max of 100mA of current and try to go up tu 5V if nothig happens chance the polarity and try again...only to check if backlight is working...and if you see light at 5V (should be standard on those displays i think) then you can try the way i have solved it (for testissues). If i have time today in the evening i try to make pictures of my displays, the changes i did on the backsides of thes Displays and the wiring of the Testdisplays i use at the moment so that i can post them here. I think it will get a little bit clearer when you see on pictures what i did. so till then...see you MaG2k Quote Link to comment Share on other sites More sharing options...
MaG2k Posted August 30, 2012 Report Share Posted August 30, 2012 (edited) oh sorry...i saw right now that direct posting of pics isn't possible. i have to look how i can upload and link them to here okay i got it. okay as i discribed at last...you can see on the following picture how i connected the LCDs-backlight (anode and cathode) directly to PIN1 and PIN2 of the LCDs Pin-Header. on the second picture you can see the first type of LCD i have in whole. and on the third picture you can see the PCBs area in detail where it is possible to change the backlights polarity on PIN15 and PIN16. (changed JP1 and JP4 to JP2 and JP3) sometimes you have to take a look into the LCDs manual but dont trust them in every detail, cause my datasheet said PIN15 (B+) and PIN16 (B-) but on the panel it was inverted. on the fourth picture you can see the backside of the second type of LCD i have in whole. and on the fifth picture the same LCD in detail. (changed R9 and R10 to R11 and R12 and closed the brindges R14 and R15) i hope that you can see and understand a little bit better what i tried to discribe. you have to search and measure (short-measuer-mode/beeper) from were to were the wires on the PCB going from anode and cathode of the backlight to PIN15 and PIN16. Greetings MaG2k Edited August 30, 2012 by MaG2k Quote Link to comment Share on other sites More sharing options...
orange_hand Posted September 2, 2012 Report Share Posted September 2, 2012 I am currently at this stage :-) Made the mistake and used flat top LED's, terrible. Especially if you have to disassemble the control surface again, like I had to :-( Good luck anyway :-) Cheers orange Quote Link to comment Share on other sites More sharing options...
Shuriken Posted September 2, 2012 Report Share Posted September 2, 2012 Very nice Orange_hand. Good Job. Quote Link to comment Share on other sites More sharing options...
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