syamajala Posted July 12, 2011 Report Share Posted July 12, 2011 I finished the CS for my fm, but it no longer turns on. The core and the opl3 module where working fine before I hooked up the lcd, din, and dout boards. So, where should I start looking? One thing I should mention, is that although I hooked up the din and dout boards, I didn't put in the shift registers yet. I thought that I would upload the proper application to the core before I put them in. Could that be the reason? Quote Link to comment Share on other sites More sharing options...
rosch Posted July 12, 2011 Report Share Posted July 12, 2011 (edited) nope, not stuffing the boards shouldn't change anything. you could start with checking where the problem is, eg disconnecting the boards and check the resistance between 5V and gnd. seems like a short somewhere. if a board is ok you could connect it again (one board at a time) and see if everything stays alright. on the lcd there's not much to solder, so you could probably spot a short visually very easy, if there is one. edit: maybe first make sure the lcd works, then the individual dins and douts. if these are alright maybe there's something wrong with the cs wiring Edited July 12, 2011 by rosch Quote Link to comment Share on other sites More sharing options...
syamajala Posted July 12, 2011 Author Report Share Posted July 12, 2011 (edited) It is the lcd. I disconnected the din and dout, then tried to turn it on the fm again, and it still wasn't working. I disconnected the lcd and it started working. I used SIL connectors for the lcd and soldered everything else. I think I'm going to get rid of the SILs. I'm not completely sure if I hooked up the lcd correctly. I'm using an optrex C-51850NFJ-SLW-ADN. According to the manual, pins 1, 2, 3 are Vss (gnd), Vcc (supply for logic), and Vee (supply for lcd drive). I hooked up Vss to Vs on the core, Vee to Vo, and Vcc to Vd. Another thing is I'm not sure if I should use +5v or +!2v to power the lcd. The manual says the absolute maximum Vee should be is 13.5v, and the recommend range is between 4.4 and 5.2v. However, I'm not sure if I should worry about current. I built a power supply using NorthernLightX's schematic, I think the transformer I used is 4A, the 7805 is 1A , and the 7812 is 1A, but since everything needs 5v and the opl3 is the only thing I have hooked up to the 7812 should I use 12v for the lcd? I haven't done any current measurements yet. Edited July 12, 2011 by syamajala Quote Link to comment Share on other sites More sharing options...
syamajala Posted July 16, 2011 Author Report Share Posted July 16, 2011 i get a black squares on the lcd now. the one on the far left is blinking too. at least it seems to turn on with the din, dout, and lcd all connected. i still haven't stuffed the din and dout though. Quote Link to comment Share on other sites More sharing options...
syamajala Posted July 17, 2011 Author Report Share Posted July 17, 2011 My lcd has a NT3881 chip on it. Is there anything special I need to do? I customized the source for my CS, and uploaded it but still haven't stuff the din and douts. I noticed once that when I played some notes on the fm the screen would flicker, but it still has black squares and blinking cursor. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted July 18, 2011 Report Share Posted July 18, 2011 Hi, just two thoughts... a) the NT3881 may not be HD44780 compatible (it would be cheapest time-wise if you could test with a proven-to-work display) b) have you tried changing the display contrast using the contrast potentiometer? Greets, Peter Quote Link to comment Share on other sites More sharing options...
syamajala Posted July 18, 2011 Author Report Share Posted July 18, 2011 The NT3881 is supposed to be HD44780 compatible. It looks like its supported by mios according to this, http://www.midibox.org/dokuwiki/doku.php?id=lcd&s[]=nt3881d I'll try the pots. Quote Link to comment Share on other sites More sharing options...
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