Hello
I have just received my handful of JeeNodes and while all works quite nice and easy when i plugged in the LCD plug it does absolutely nothing... i've tried playing with the onboard pot. and recheched the connection to the LCD (the one in the JeeShop) but no chance of getting the example code running.... any ideas ?
Do i have to put a jumper in the SW place and connect it ?
LCD plug
(16 posts) (8 voices)-
Posted 22/01/2010 10:12:58
-
You have to place three solder jumpers - or two and a backlight resistor. See http://news.jeelabs.org/docs/lp1.html
Posted 22/01/2010 11:10:16 -
yey! now i see it.
i've soldered the jumpers like in the folowing photo:
-the one that says LIGHT - soldered the middle one to the bottom one;
-the one that says LOGIC - soldered the middle one to the top one;
-and soldered the 2 small padds where the resistor should be.Then connected it to USB and run the demo, it works like a charm, thanks Jean-Claude!
Any ideas if this setup can run in the long term with no damage to the uC's like heating... or for the small transistor ?
Posted 22/01/2010 16:41:43 -
i know there is a method to turn the back light off... but can't seem to find the command.... any hints please... :D ?
Posted 22/01/2010 16:57:08 -
turning off the display touched here: http://talk.jeelabs.net/topic/69#post-268 but i don't have an idea on how to turn it back on when i need it to (not when there is a new char. printed)
Posted 22/01/2010 18:12:27 -
This was on my to-do list, I've added backlight() and noBacklight() to the LiquidCrystalI2C class. Please get latest code and try again :)
Uses a bit of a hack - the backlight bit in the I2C expander is set as input to turn it off... that way the other code is not affected.
Posted 22/01/2010 19:01:40 -
yep... lcd.backlight() and lcd.noBacklight() they work like a charm. 10x
Posted 22/01/2010 19:33:22 -
I had the same problem at first.
I had forgotten to solder the 3 pads.Now I can get the backlight to come on and blink.
But I can't seem to get text to display.Any ideas what I missed?
Posted 13/03/2010 04:09:40 -
Same problem here. Soldered all 3 Pads (2 on 3v, 1 on the resistor-pad). Backlight is blinking but no text.
Posted 13/03/2010 14:54:19 -
I had exactly the same problem - and in my case the solution turned out to be that the onboard pot did not move when I tried turning it using a small screwdriver, it just felt like it did. Try turning it all the way counter-clockwise, and in my case everything started working.
Posted 13/03/2010 16:28:22 -
Ok.
Thanks for the tip turning the pot more.
I got the LCD so now it is just barely visable.and I turned it all the way counter clockwise i feel. I can see it barely visable. Any way to get the contrast higher or have that same issue?
Posted 13/03/2010 19:13:44 -
What kind of power source you're using? Using 5V might help. I had the same thing when using (too) low voltage supply.
Posted 13/03/2010 19:30:37 -
As long as you can see the characters faintly there are only a few more things that could have gone wrong :
- For my LCD display both the "light" and "logic" pads have to be soldered to "hi" - as my LCD displays need 5 volts.
As the previous poster stated that means that you need to use either the USB-BUB board, or the USB jeeduino to make sure that you have +5 volts available on the PWR pin, it will not work (at least with the LCD's I have) just from the Jeeduino's 3.3 Volts.
Posted 13/03/2010 21:33:03 -
That must be my problem then. I don't have enough power, since I am using a 3-4.2V source. RATS. I was planning to get by to use a LIPO to power the whole thing and have a display to test with. But if I need 5V that is going to be a bit trickier. I thought I had a great power solution worked out.
Now off to run it off of 5V for testing?
Posted 13/03/2010 23:11:53 -
If your display needs 5V power , maybe this is something .
http://www.sparkfun.com/commerce/productinfo.php?productsid=9054
Posted 14/03/2010 09:07:18 -
You can alvays make 5V lcd to work on 3,3V by applying negative(for example -3.3V to contrast pot leg instead of ground). + decrease the backlight resistor =).
If you ask where to get negative voltage? - check something like LMC7660 http://www.national.com/ds/LM/LMC7660.pdfPosted 15/03/2010 07:37:31