
kplamondon

I found an LCD screen that has 4 ports, 2 being 5v and gnd; the others being called SDA and SCL. The LCD screen has 4 lines that can be written, my main goal is to set up the LCD screen so that when my rover 5 drives in different directions it is written on the screen. Also if read the forum before this one my rover 5 is going to go into harmful gases, detecting if they exist in different areas. If it does i want to put a warnings on it, etc so it can be read.
My main concern with this is how to connect the LCD screen and a basic code that would print something simple like "hello world" onto it, from there i can infer what i need to do for my different print statements or whatever term is used to do this.
Devantech LCD05 is what to look for if you can't buy from a UK based company. While they may cost a bit more they are very much worth it.
What LCD is it? Do you have the datasheet? You will need the datasheet to know the commands to use. Be aware of the cheap ones on ebay, they are near impossible to work out.
http://www.amazon.ca/gp/aw/d/B0080DYTZQ/ref=aw_d_dsc_sdp_misc?qid=1373601918&sr=8-7
http://www.amazon.com/LCD-Module-Arduino-White-Blue/dp/B003B22UR0/ref=sr_1_3?s=electronics&ie=UTF8&qid=1373597891&sr=1-3&keywords=serial+lcd
I toally agree that going serial would be easier, but just how much would i2c be harder if this LCD happens to be i2c. If i2c is a lot harder and this isn't i2c I may need to just buy a serial and be prepared for expensive shipping.
In short avoid the one I mentioned in this topic which is the "IIC/I2C/TWI 1602 Serial LCD Module Display" with the "YWRobot Arduino LCM1602 IIC V1" backpack.
Make sure you get the datasheet, not the Arduino code. You will need to know the address of the LCD (if I2C) and all of the commands to move the cursor, clear the screen, define any custom characters, print characters to the screen etc.
The one @toymaker mentions in this topic which is the same Devantech one I mentioned earlier is by far the simplest to use and can be serial or I2C.
The one mentioned in this topic is also pretty easy to use and both Serial and I2C, I have done some examples for that one too.
@kplamondon if, on the other hand it isn't complete please ask for further help.
To be honest, I would always advise/recommend the Devantech LCDs. They may be a little more expensive than the useless ones from ebay but they are very easy to use and are both Serial and I2C so needn't use up one of the digital ports if you are low on ports. I've also covered using the LCD in some depth, have used it a lot for many different applications recently and know that Tony (@toymaker) also uses these a lot so there will always be a lot of help if needed.