As it turns out there is a problem in compatibility.
lifted from - https://www.sparkfun.com/products/9363
I just noticed a similar problem with the LCD shield connected on top of the Ethernet shield. The LCD shield starts up, but there seems to be a loop quickly refreshing the image of the Sparkfun Logo with the white background. This image was tied to the S1 button when the LCD was connected directly to my Uno.
Still no response from anyone with any information on this issue? ..Disappointing..
Is the code you have for writing on the lcd in the loop or setup part of the sketch? If it’s in the loop it will automatically redraw it every time it goes through loop unless it is in a conditional element.
The code is exactly as provided on your blog; I put it on my Arduino for a way to quickly get familiar with this shield. My problem is as follows: When the shield is directly connected to the base Uno the code seems to work fine, but when the shield is connected as LCD —> Ethernet —> Uno the code seems to infinitely be looping in refreshing the Sparkfun image with white background (code is still unmodified).
Are you using these with a Duemilanove?
I’ve noticed the same issue. After a little bit of noodling, I think it might be linked to the way that the LCD’s code is accessing the LCD vs. what is expected. Out of curiosity, are you also including the Ethernet library when you hook up the ethernet shield?
Also, the LCD shares a pin with the Ethernet shield (pin 4 for switch/button 2). The ioinit code for the LCD seems to set this pin as an Input which, from reading on the Ethernet Shield, might make the SD card slot angry. Not sure how angry, but perhaps angry enough to upset the controller/communications. Removing that and setting it as Output doesn’t seem to help much. I can get it to display some stuff, but as soon as I start using the Ethernet library, everything goes off to never-never land. I am wondering if that has to do with the Ethernet library coded to use the SPI library and the LCD library coded to send hard bytes over the SPI bus…
I’ve been meaning to try my hand at recoding the LCD Library to use the SPI library, but I haven’t had the time to look into it and I’m still relatively new to the whole thing.
Has any one got this to work with the Ethernet shield ? ,I really want to get this screen but if it wont work with the Ethernet shield it will be pointless for me.
I’m having exactly the same problem. I’ve already bought the shield. My separate test sketches worked fine. The second I integrated them all together, it stopped working. I am wondering, as I am not using the SD card or the buttons on the LCD shield, can I alter one of the libraries slightly to not include a section that is causing this problem? I’m new to this realm of development. Any suggestions of shields or Displays that work well showing or representing serial data, or any solutions to this problem would be much appreciated. The shields look so good stacked up together, it would be a shame to use an external 16x2.
Any ideas on how to remedy this?
I'm using the <gLCD.h> LCD library and Ethernet shield. .. I was wondering, As I don't need to use the buttons on the LCD shield OR the SD card on the Ethernet, would removing these sections from the libraries make any difference? My first thought - no, because they are not called upon in the sketch. It's a long shot but I'd rather tackle this problem and use a tidy looking LCD than fork out another £20 for a 20x4 just to display serial data on location.