Hi,
I can't get any life on to my lcd. What would be the reason?
I highly appreciate your help. I'm kinda new to all this.
BTW I haven't soldered it yet. The leaads are just bended there. Could that be the reason?
br
-orbitrek
This is my setting:
This is my lcd:
http://www.messtechnik-online.at/bauelemente/pdf/162c.pdf
And the code I tried was those basic exaqmples from arduino.cc
E.G.
// include the library code:
#include <LiquidCrystal.h>
// these constants won't change. But you can change the size of
// your LCD using them:
const int numRows = 2;
const int numCols = 16;
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup() {
// set up the LCD's number of rows and columns:
lcd.begin(numRows, numCols);
}
void loop() {
// loop from ASCII 'a' to ASCII 'z':
for (int thisLetter = 'a'; thisLetter <= 'z'; thisLetter++) {
// loop over the rows:
for (int thisRow= 0; thisRow < numRows; thisRow++) {
// loop over the columns:
for (int thisCol = 0; thisCol < numCols; thisCol++) {
// set the cursor position:
lcd.setCursor(thisCol,thisRow);
// print the letter:
lcd.print(thisLetter, BYTE);
delay(200);
}
}
}
}
orbitrek
BTW I haven't soldered it yet. The leaads are just bended there. Could that be the reason?
Yes.
STOP RIGHT HERE. You would be better off soldering pins (or short stiff wires) to the LCD module so you can plug it into your breadboard.
Next you have to verify that you have the correct power applied and the correct contrast (potentiometer) setting. Do this before you connect the rest of the wires. Write back if you need more info about this part.
You should also make sure that you are using Arduino v0017, or at least the LiquidCrystal library from that version. I would also recommend starting out with the 'Hello World' example from that library. Cut and paste it to avoid typing errors.
lcd.begin(numRows, numCols);
This is backwards for the library mentioned above. It may or may not be correct for the one you are using.
I originally thought your R/W wire was connected to +5 volts instead of ground but you tricked me with your backwards (to me) color coding of the wires.
Don
UPDATE:
It looks like you got your example code from the 'Hello World' example in the playground, specifically at http://arduino.cc/en/Tutorial/LiquidCrystal.
This example shows
lcd.begin(numRows, numCols);
which is the code you used. Obviously we have a problem here.
The bottom line is that I know that the example from the actual library works. I will check out the playground example and report back shortly.
Don
Update to the UPDATE:
Well, the bottom line is that they both work, so there is something else going on here that probably should be investigated in another thread. If someone who has more experience in C programming than I do (which would include just about anyone) doesn't chime in soon with an answer I will start a new thread in 'Bugs and Suggestions'.
Don
floresta wrote:
Next you have to verify that you have the correct power applied and the correct contrast (potentiometer) setting. Do this before you connect the rest of the wires. Write back if you need more info about this part.
So I should build a setting which only applies a supply voltage to the lcd. Should the lcd then be lit. And when I get it lit, I can move on to connect the rest.
Well, the next step is to solder those short pins.
And yeah, sorry about my wire coloring.
Great thanks to your guidance. I get back when I've succeeded/unsucceeded in next steps.
Now I got to go ZZZ.. its 01:44
-orbitrek
So I should build a setting which only applies a supply voltage to the lcd.
You need the supply voltage and the potentiometer to supply the contrast voltage. Pins 1, 2, and 3. One end of the pot is connected to +5v and the other end is grounded. The center connector goes to pin 3. Typically you should get a blank screen with the pot at one end (contrast = +5v) and some really dark boxes on the top row of the display with the pot at the other end (contrast = 0v). Adjust the pot until the boxes are just visible. This typically results in a very small positive voltage on the contrast pin and many displays are actually usable with the contrast pin grounded, and with those you can get away without the pot.
If you can't see the boxes don't bother trying to load and run any code. In this case you may have an extended temperature LCD display which requires a negative voltage on the contrast pin.
Well - when you read this I will still be asleep. I'll check back tomorrow and see how you did.
Don
Ok thanks,
So if I have "an extended temperature LCD display which requires a negative voltage", how would I know that. The spreadsheet doesn't give any hint as far as I understood it. Or to be accurate, there was a statement on the page 3:
" LCD Driver DrivingVoltage --- V0-VSS "
Does this mean that it is positive?
What would be easiest way to get negative voltage? I now only have the arduino as my power supply for the lcd.
I believe and hope I have time to mess around with my LCD again late at night.
-orbitrek
LCD spredsheet:
http://www.displaytech.com.hk/upload/product/attachment/982-162c%20series-v20.pdf
Just wanted to point out, you've got the R/W pin wired to 5v.. which leaves it high, which means you're always trying to read from the LCD. You'll never be able to write to the LCD with that pin on 5v, put it on ground instead. This will enable you to always write.
lol hope this wasn't explained before but there was too much reading for me, glanced over some. 
No, it is grounded. As far as I can see it in the picture correctly. I'll recheck that when I'll get back home.
Thanks..
Well it's pretty hard to tell.. especially when you're using the opposite colors for positive and negative.. lol ( I finally took the time to read the post and see that Floresta already had this problem.. lol:))
You may need to plug in your backlight to see text.. and like Floresta said, make sure you play with the potentiometer for the contrast.
Other than that, I'm voting on the connections..
This is old, but I just update this if someone searches for a piece of info.
So everything was done right, except the connections. It just started to work after I soldered everything properly.