LCD I2C (DFR0063) not working

userHead eecher 2011-12-16 06:28:00 5927 Views4 Replies

I recently bought an I2C-LCD combo (DFR0063) from DFRobot.  I can't get it to work at all.  I've updated my Arduino IDE to 1.0 and have tried several different versions of the I2C-LCD library.  I figured the "real" one from here:
would be my best shot, but no luck so far.  I actually had more success with this LCD unit when I had the SDA and SCL lines reversed--  at least then the backlight stayed on!  As it is, with everything hooked up correctly, the i2c address set correctly in the code and the IDE agreeing that the code compiles properly, nothing works.  I turn the power on the my Arduino, and the LCD's backlight blinks a time or two, and then stays off when the code says it should be on.  If I try the serial display example (where what you type in the serial monitor should be displayed on the LCD), no text ever appears, and the serial messages serve simply to turn the backlight on and off, some but not all of the time.  No text is ever displayed.  I've tried using both sets of connectors on the i2c backpack, with the same results.  Don't even ask about the "Hello, World!" example-- the backlight never turns on.  It seems like this unit completely sucks...  anybody have some magic solution for me?
2011-12-20 03:52:40 Thanks for checking in.  I haven't had time to try the display with a higher voltage power supply yet, but I hope to do so later today and will let you know what happens.
userHeadPic eecher
2011-12-19 11:53:17 Eecher,

Any progress? Let me know. If you can't get your LCD to work, we will try to get you a replacement, and we'll even test it for you before shipping. If you don't get it working open a ticket in the [url=;sa=main] helpdesk[/url]
userHeadPic Hector
2011-12-17 03:18:47 - Using male-to-female jumper cables.  The female ends are very snug, but I'll see if I can find and rig up a 4-conductor cable.

- Haven't tried using a non-USB power supply.  I have a 9v and 12v supplies that I can try.

- Definitely have the SDA and SCL lines going to the right pins on the Arduino now, and have adjusted the contrast as best I can.  I've never had any text appear while the backlight was on, so it's hard to say, but I adjusted it similarly to how I've done it with the other 16x2 non-i2c displays I've used.  I did see a "blinking cursor" appear on the display once without the backlight on, which was the only time I've seen anything legible appear on the screen at all.

- Apparently the Wire library changed alot with the 1.0 IDE update... I guess I'll try to go back to 022 with everything.
userHeadPic eecher
2011-12-16 10:46:49 Eecher,

How are you making your connection to the LCD? I mean, which type of jumpers are you using. In my experience, some of the female pins can be loose, which this LCD does not like one bit, this particularly happens with individual female pins, so try using a 4 pin female socket. Also, have you tried adjusting the contrast on the back of the LCD?

One more thing. The Arduino IDE V1.0 is very new and many sample codes and libraries are not yet compatible with it (This LCDs library has been updated for compatibility). I would recommend sticking to IDE 0022.

Please make sure that you connect SDA to pin 4 and SCL to pin 5 on your Arduino. Are you providing power directly from your Arduino to the LCD? Have you tried providing extra power to your arduino through a power adapter? Sometimes the USB power is not enough to drive external components.
userHeadPic Hector