I'm considering getting a 3.2" TFT and the project may have Ethernet support later
First the TFT:
I assume that there are no differences between Sainsmart one and the one from ITead Studio except for the name?
Then for something more important. I can't have the display the running all the time. In another thread I found some code to shutdown the display controller itself. This leaves the backlight running. For that I found a hack to switch it off with a transistor. If the touch screen controller is still running I can then use that to turn it on, or install an extra button if that doesn't work.
Which brings us us the adapter shield for Mega. There are two versions. The old one:
and a newer one:
http://www.elecfreaks.com/store/lcd-tft01-arduino-mega-shield-v20-p-214.html
http://imall.iteadstudio.com/development-platform/arduino/shields/im120417024.html
The new one seems clearly superior. It has line buffers and appears to have its own 3,3V voltage regulator instead of using the 3.3V from the Arduino. That one seems weird in the old version, since I read that the backlight can draw around 100mA.
But, it doesn't have the potentiometer, which means I can't easily access the backlight LEDs with a transistor. Should I just get the old version, or are there other options here? (I know that I could theoretically switch all I/Os to Tristate and cut off the power with two transistors, but that seems overkill here).
Now for the Ethernet shield. I don't need this right away, but if I install a standard Ethernet shield, the double row on the right side obviously isn't connected anymore. I thought of using pin headers, a ribbon cable and these connectors in the right size:
http://www.reichelt.de/index.html?ACTION=3;ARTICLE=14575;SEARCH=PFL%2026
This has the advantage that I gain easy access to the 8 or so unused pins there.
An alternative may be to use an ENC28J60 instead and try to hook it to the ISCP header with such a connector. But I also read that this controller is inferior and not recommended. There seem to be several competing libraries...
Has anyone combined a TFT with an Ethernet shield? I searched but couldn't find anything.