Use an ethernet shield and LCD at a time

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

I'm Spanish and my English is not so good.
I have a problem, I have a project with Arduino, but I need to use an ethernet shield and a LCD screen at a time, but I see in the arduino page that they use some pins simultaneously.

How I can solve this problem?

2

Use a serial display either rs232 or an I2C display these need far fewer pins.

If you want to use a parallel display, you can select using 8 or 4 pins, choose 4. With the LCD lib you can select which pins to use. The ethernet uses pin 10..13 so you just should select some other. Note you can use the analog pins as digital ones.

3

You need at least six Arduino pins to control a character mode LCD module using the LiquidCrystal library. You do not have to use the ones specified in the examples but you do have to specify which ones you use when you initialize the library.

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

should be thought of as:

LiquidCrystal lcd(RS, E, D4, D5, D6, D7);

just substitute the pin numbers that you use for your connections to the LCD module.

Don

4

as @floresta said.
It's the easiest way.
I have a tutorial on my posterous if you want.
I use the ethernet shield to do telnet and the display to display a message.

You can have a look at the section on how to use both.

http://asselinpaul.posterous.com/arduino-telnet-client-display

Sincerely
Paul

5

I am also having this problem,
I cant use Digital pin 4 because that is used for the SD card, (its undocumented on the schematic but I know this for a fact because I have the sd card working with the third party library)

I know I can use the Analog as Digital but my question is will the LCD library understand A# (# is whatever analog pin you set) in the pin setup as shown below

LiquidCrystal(rs, enable, d4, d5, d6, d7)

Also arnt Digital pin's 1 and 2 used for the USB?

This is a major problem as I need to present my work within the next 5 days so a speedy response would be Extremely appreciated, Thanks!

6

As far as I'm concerned, you can use the digital 1 and 2 with no problem.

7

ok so 1,2, and 8 are open for me but i need 3 more to get the lcd to work

so my question still stands, will the LCD library understand and use the A# analog pins in its setup?

8

Am sorry I don't know the answer.
I know you're short on time but you could check out an i2c / SPI character LCD backpack. They basically decrease the number of pins needed to control an lcd.

here is a link to the one adafruit sells:

Good luck

9

I know I can use the Analog as Digital but my question is will the LCD library understand A# (# is whatever analog pin you set) in the pin setup as shown below...

I believe that the library can use the analog pins 0-5 when they are referred to as 14-19. Try it that way and if it works then substitute the A0-A5 version and report back to us.

Don

10

I know I can use the Analog as Digital but my question is will the LCD library understand A# (# is whatever analog pin you set) in the pin setup as shown below...
I believe that the library can use the analog pins 0-5 when they are referred to as 14-19. Try it that way and if it works then substitute the A0-A5 version and report back to us.

Don

yep see the note on - http://www.arduino.cc/en/Reference/DigitalWrite
Don't forget to set pinmode to OUTPUT;

11

Thanks guys, unfortunately i have run into some trouble with my LCD I believe "the technical term is my %#!* done busted" (Lotek song reference ;)) So I will report back on my findings as soon as i get a new lcd.

12

If you get another one... head over to moderndevice.com... they got the 16x2 or 20x4 LCD there, and a driver board as well that will only use one digital pin on your arduino (the TX pin). That is if you use hardware serial with it. If you use software serial, you can use whatever pin you wish.

13

robtillaart:

You have to use nested quotes to get it to look right.

One quote:

I know I can use the Analog as Digital but my question is will the LCD library understand A# (# is whatever analog pin you set) in the pin setup as shown below...
I believe that the library can use the analog pins 0-5 when they are referred to as 14-19. Try it that way and if it works then substitute the A0-A5 version and report back to us.

Don

Nested quotes:

I know I can use the Analog as Digital but my question is will the LCD library understand A# (# is whatever analog pin you set) in the pin setup as shown below...

I believe that the library can use the analog pins 0-5 when they are referred to as 14-19. Try it that way and if it works then substitute the A0-A5 version and report back to us.

Don

Don