Using Lcd Displays

I am new to Arduino and to using forums so I hope I am posting in the right place?

I have just bought the i2c 16x2 lcd display and wondered if I could still use the older displays that do not have the serial backpack installed after installing the library in the arduino ide, as I have managed modify a few sketches from other arduino users and dont want to lose the use of them by not being able to use the old lcd's, in time when I am more familiar with serial lcd's I will rewrite the code in my sketches.

Another question is how long can the wiring from arduino to such things as sensors and relays be before they are long.

wondered if I could still use the older displays that do not have the serial backpack installed

If you don't use the new library, it will have no impact just because it lives in the libraries folder.

Thanks for taking the time to reply.

I found the new lcd library at https://arduino-info.wikispaces.com/LCD-Blue-I2C and near the top of the page it says NOTE!! Move any other LCD libraries to another folder,or rename or delete them.

That is why I am not sure how to proceed.

The I2C drivers for the LCD are readily available.

http://www.dx.com/p/lcd1602-adapter-board-w-iic-i2c-interface-black-works-with-official-arduino-boards-216865#.Vb3nSkrXerU

The length of the cable to sensors is a general one but it depends on the sensor or output device.

You can feasibly drive a relay at the end of a Km cable given the right voltage.

You need to be specific on the device in question.

Weedpharma

weedpharma:
The I2C drivers for the LCD are readily available.

True, but we can only recommend that you use the more familiar fmalpartida library (and remove any and all other LiquidCrystal libraries from your IDE path) and then use bperrybap’s “i2cLCDguesser” script to determine the correct descriptor to use with this display and backpack, which descriptor you then copy into whatever sketches you want to use.

NOTE!! Move any other LCD libraries to another folder,or rename or delete them.

I think that the phrase "of the same name" was left out. Some people are too self-centered to realize that there may be other people developing libraries that do the same thing, with different hardware maybe, with a slightly different name.

Thanks to all who took the time to reply to my questions.

It seems I was unduly concerned about using the new lcd library I decided to bite the bullet and use it, once I found the correct code for my lcd it was just a matter of cutting and pasting the code from the sketches that I had already got working and so far all is well.

I got the info needed from the site below so thanks to the people responsible for posting.

http://www.datsi.fi.upm.es/docencia/Informatica_Industrial/DMC/LCD-Blue-I2C.htm

The reason I asked about cable lenght is because I want to use a pir sensor to protect a garden shed using arduino uno a 5volt relay and an lcd display to report "Motion detected" on line 1 and "Intruder Alert" on line 2, the lenght of cables running between the components will have to be a few meters long and if my memory serves me low voltage does not travel long distances. The project is still in the early days at the moment.

5V running over lengths of 5 mtrs should not present a problem with low current sensors.

The distance depends on the current and size of the conductors.

Weedpharma

And most importantly - do not use separate wires. Shielded cable may be a good idea, using the shield as the ground conductor.