ok i have this lcd http://www.character-lcd-lcds.shopeio.com/inventory/details.asp?id=436 and i dont have a 10k pot or a 10 ohm pot to control the back light and contrast but i do have resisters, so i want to know whats the lowest and whats the highest resistor i can use? So i know what the range is so i can try different ones.
If you have any other pots available, pretty much anything between 1k and 22k should work acceptably. If all you have is normal resistors, use pairs of them as potential dividers, whose total resistance = approx. 10k. eg. try a 5.2k and a 5.2k in series, with the contrast pin attached between the two. If this is too dark / light, then try an 8.2k and a 2.2k in the same way, then a 2.2k and an 8.2k. (ie. reverse the resistors positions) Trial and error will get you to the right contrast in the end. If the above is confusing, I can make up some schematics to explain it better. If you want to know a bit more about how these screens work, rather than just wiring it up to the parallel port, I suggest you take a look here: LCD guide part1 and part2. This screen uses the same chip and works in the same way.
would it be a good idea to wire everything up to a bread board so i dont have to solder all that crap over and over when trying different resistors?
That would be an excellent idea. I use breadboard for testing virtually every circuit I design for that very reason. (Try makins something like this without a breadboard for testing. (The link is to a picture of one of my own projects)) For complex projects, I tend to buy two sets of components if I can afford them - that way I can design and build the PCB, and if there is a problem, I can refer back to the working prototype to help fix them. The spare set of components usually get re - used in other projects.
dang what exactly does all that do? I think ill just wire it to the breadbored, Ill just take off the wires from my printer/parallel connector connect those to the bread board and use some telephone wire (22 gauge) and conenct it to the lcd, after i get it to work, ill go and de solder the telephone wire and hook up the wires from the parallel cable to the lcd btw, how can i check which number each wire on the parallel cable is? volt meter? (what do i look for) and also what would happen if i didnt have any restitors or anything? cuz look at this guide http://www.overclockers.com.au/techstuff/a_diy_lcd/ no pots or resistors i have a question about the power wires. So 3 wires are for gnd, and another is for what 5 volt? i plug them all into the same molex right? how do i arrange them? could i just connect 2 gnd wires together and connect it to one gnd wire on the molex, and the 3rd gnd wire to the other black wire on the molex? and then where does my 5v wire go to?
Hey there i recently bought a Seiko L1642B1L 2x16 LCD http://www.character-lcd-lcds.shopeio.com/inventory/details.asp?id=436 heres the pin layout http://www.eio.com/l1682.pdf ok reading this guide http://www.overclockers.com.au/techstuff/a_diy_lcd/ it doesnt say anything about wiring up resistors/potentiometers, but on many other guides it does. I have a few questions, if i do need resistors, whats the range (ex: 2k to 10k or something like that) And what do i hook my back light wires up to? Theres the two points labeled like C and A i think, but where would i hook those wires up to? And how do i figure out which printer wire goes to which point on the LCD? a volt meter? And for the power, on the pin layout theres only pin 1 (which is GND) and pin 2 (which is +5v) in the guide theres 3 gnd's and one 5v. SO wheres my other 2 gnd's? And when all the power wires are connected, which order do i plug it into the molex connector? do i plug the gnd into any black wire and then where do i plug my 5v into? if i have anymore questions ill ask thanx
resisters only if you want to adjust the display, the back light is pins 31-32 it says its an led so it should only nead 2 volts, you look at the pins on your printer cable and see witch ones go with the ones on the otherend of the cable, the guide was HIS lcd if yours only has one + and one - then you only nead one of each, ground to black posotive to red(well I think thats the color,whatever color other than black and yellow. oh and 6 bucks for a back lit lcd with 2 buy 16 thanks I was looking for a better one. how much was shipping.
shipping was like 7, my total was 13 bucks hmm at digikey.com or whatever, they sell 10k pots and 100 ohm pots for only .83 cents each, shipping is 5 bucks though lol i might just buy those
