ok.. i just brought another LCD sreen off one of the bit tech members... and i need some help wiring it up... now the lst one i had i accidently blew it up because i wired it up wrong i want to try and avoid it this time if possible.. the guy that sold me the LCD doesnt remember what guide he used to wire up his but he said it was one of the guides mentioned in the LCD FAQ sticky now of what i can see of it.. i can easily identify a row of pins 1 - 14.. and to extra holes down the other side... now ive put a 5v power source to pins 1 and 2 and the green backlight came up... i no there are many guides around here and on the net but i no that not all the LCD's are the same layout so thats why im here.. i will post a better quality pic a bit later on 2day but here is a less clear one that i got off the guy that sold me the LCD any help would be apreciated...
here's how i wire mine... pins 1-14 are as follows: lcd pin 1- this pin will be the ground pin, or on a few displays i have seen this one be the +5V. if it's the former, you will connect it to the black wire on your molex power connector. lcd pin 2- put a resistor on it (10 ohm or less) and then connect the other end of the resistor to +5v (or if pin 1 is +5v, this one is ground) lcd pin 3- contrast control... connect it to the wiper pin on a 10k pot. connect the outer two legs of that pot to +5V and ground lcd pin 4- this one goes to pin 16 on the parallel port cable. lcd pin 5- pin 14 on the PP cable. lcd pin 6- pin 1 on the PP cable. lcd pin 7- pin 2 on the PP cable. lcd pin 8- pin 3 on the PP cable. lcd pin 9- pin 4 on the PP cable. lcd pin 10- pin 5 on the PP cable. lcd pin 11- pin 6 on the PP cable. lcd pin 12- pin 7 on the PP cable. lcd pin 13- pin 8 on the PP cable. lcd pin 14- pin 9 on the PP cable. pins 18-25 on the parallel port cable are all tied to ground. *pins 10, 11, 12, 13, 15 and 17 on the parallel port cable have no connections.
i no that pin 1 is ground and 2 is 5v... that powers the backlight i believe when i hooked it up.. im gonna give the pot a try..
i connected a wire to pin 3 then to the pot then 2 other wires to 5 and ground and nothing is happening..
the contrast control will not change the brightness of the lcd. you won't be able to see the contrast control do anything until you have the lcd hooked up to your pc. it will change the contrast of the characters... you will have to adjust it to almost ground... alternatively you can connect pin 3 to ground, it's just nice to have the option to adjust it if needed...
i thought that hooking u p pin 3 to a pot allows you to check if you can actually get the character boxes up..
nope. (at least i don't think)... the boxes won't appear until it's hoked up to the parallel port. i think this has something to do with pin 4,5 or 6... the rest of the pins (7-14) are data pins.
For starters, what model/make is the LCD? Secondly, if putting 5V across pin1 and pin2 turns on the backlight, then those are not pins 1 and 2. The HD44780 format is this: Pin1=ground Pin2=5V supply for logic Pin3=contrast voltage Pin4=RS (register select, to switch from data or command) Pin5=R/W (read or write) Pin6=E (chip enable) Pins7-14= DB0-DB7 (data bus) Pins 15 and 16 (if there are any) are usually for the backlight. If you give pin1 ground, pin2 5V, and put the wiper of a 5K pot on pin3, then you should be able to get a test screen. This is where you will see a bunch of blocks. PS: I have seen LCDs that had thier pins a little backwards before ie- pin15, then pin16, then pins1-14. But these were clearly labeled.
ok ive got some proper pics of my LCD here.. this one is of the front of it.. this is the back of it.. now i put 5v and ground to the 2 holes by the white part where you can see + and - and the back lit up... and i did the same to pins 1 and 2 and the same thing happened.. edit: sorry about the size they are saled down a bit...
i have some lcds that are wired the same way... it's convinient actually, i think. if both the logic and the led backlight need 5 v, then it only makes sense. i can see in the pix where pins 1 and 2 are connected to 15 and 16.
ive wired it up to the specifications but im not getting anything on the screen except the test screen... edit: dont worry it just neeeded a bit of a wiggle and now it works.... also whats the best way to be able to turn it on and off when i like.. when i cut power to it and turn it back on i have to restart lcd smartie..
Isn't there a way in LCD smartie to do that. Otherwise, make a profile or whatever with only 1 empty screen and turn ye backlight off.
it works and it doesnt... i no it does work properly.. but i think some of the wires are touching the others.. so im gonna have to rewire it again :'( it did work the 1st time i did it but when i put it down to go to sleep i woke up and a wire had come off and everything started to go wrong after that
it's best to use connectors and breakaway headers. mouser.com is a good place to get them, there are alot of other sites to find them on too... i use breakaway headers on the pcd of the lcd itself, then i crimp terminals onto the parallel wires, the same kind of pins you find inside of the 3 pin fan connectors. are you soldering the wires straight to the lcd's board?
i am soldering them straight to the pins they have on there... what do these headers look like i might be able to find some at my local electronics shop
here are the mouser.com part numbers for the housings and pins i was talking about- crimp terminals- 538-08-50-0114 housings- 538-22-01-2xx7 (fill on the xx with however many positions you want it to have... i.e.- 16p would be 538-22-01-2167) headers- 517-2340-6211TN oh- and the housings i listed do match up with the headers, although the housings have a locking ramp and the headers don't...)
