My paralell LCD module isn't responding.

Forum 2005-2010 (read only) Hardware Interfacing
1

I followed Ladyada's tutorial up until the point where you plug in the arduino and you see little blocks on the screen. The reason I stopped was because, well, no blocks appeared on the screen. I've tweaked my contrast around quite a bit and still nothing. I've not tried putting in arbitrary values of fixed-value resistors, for fear of blowing my display. If anybody has any ideas of ways to troubleshoot, fire away.

Here's the tut in question: Arduino Tutorial - connecting a parallel LCD

2

I'm having a similar problem, but it's with multiple Hantronix 16x2 LCD's (part# HDM16216L-5-E30S). 3 of the 5 that I ordered do not work with my SparkFun Serial Enabled LCD Backpack or wired up via parallel to my Arduino. I haven't messed with the other two in case I need to send them back. The pinouts are the same as the SparkFun Hitachi 16x2 LCD. My symptoms are that the backlight comes on, but nothing is displayed on the screen. No matter how I adjust the contrast, I never see black blocks, or anything for that matter. Have you resolved your issue and if so, what was the problem? Does anyone have any experience with the Hantronix LCD's? Am I overlooking something simple? :stuck_out_tongue: I can't imagine getting 3 bad LCD's all in one batch.
-John

3

same problem here with a lcd from an old HP server. Backlight works but I am not able to see any blocks on startup..
Pin 13 should be linked to the metal of the lcd I read somewhere but that is not the case with this lcd

4

Not unless it's a 4x40. Are you sure you wired it up correctly?

http://home.iae.nl/users/pouweha/lcd/lcd0.shtml#pin_assignment

5

I had no problems using an Optex 51505. I did try a NewHaven LCD that I could not
get running.

On the 51505 you can short the VLCD pin to 5V for one contrast level and 0V for
the opposite level. Check your datasheet for the wiring.

Also verify the pinout of your connector. Make sure you are looking at the pins from the proper side of the board. The pinout is mirrored if you look at the wrong side.

I will be releasing an LCD board for my ZB1 board shortly. It will have a
schematic which is very similar to the LadyAda drawings.

(* jcl *)