Arduino uno + ethernet shield


Iam quite new to arduino so maybe my question will be silly but I want to use Arduino Uno + Ethernet shiled + touch LCD. My question is, if its still possible to use some free pins and if so, how?

For example if I just connect the ethernet shiled to my arduino uno r3 i see that some pins on the arduino are free but they are not labled. On this picture LINK they are labeled as A5, A4, NC and IOREF. There are also some 6 pins right above the AREF labeled as GND, A1, D10, D9, 5V and D11 …

So have no idea if some of those can be used?

Iam asking becuase if I connect the Uno + Ethernet + LCD (with shield pins), there will be no pins left co connect anything else and I would need the +5 and one digital pin and GND to connect some speaker in order to play some sounds also…

Do I need to buy the Mega? Or can I by any chance use some of those pins?

Ethernet shield uses pins 10, 11, 12, and 13 on your Uno. 11, 12, and 13 are the SPI bus, so you can connect as many other SPI devices to those pins as you like, but you can't use those pins for purposes other than SPI.

I don't know what pins are used for your touch LCD.


the thing is I was thinking about buying LCD shield version that has pins directly for conection to the Arduino Uno (so I guesss there will be no big deal to connect it on the ethernet shield as well). But if I do that, ist like when you put LEGO cubes on top of each other - there will be LCD at the top but no free pins anywhere, because its all connected - LCD to ethernet shield, ethernet shield to uno....

At this time, I have LCD that is not for the shiled (so I have to wire it through the resistors and it has some weird issues like sometimes the display is just white, sometimes it works but its registreting touch even when you dont touch it at all, so the example code that should show your touch x a y is constantly refreshing and changing the values like meaningless.... not registrering my touches. Odd thing is when I change the if(ts.touched() statement and add the }else{ at the very end, it seems to work for the next test just fine. But I have not a clue why because closed IF should work the same way with or without ELSE) that uses 10 pins on the ethernet shield (D7-D13 and GND, 5V and 3,3V. Then I have RFID reader that needs 3 pins (+5V, GND and D2) and I also wanted to connect the speaker which uses 3 pins (+5v, GND and should use D9 - which will be a little problem because this pin is used also for LCD but meabe it can be changed)

EDIT: ok I take it back, seems it randomly doing it again - just refreshing the x and y as if I was touching it even when Iam not :frowning: