I am trying to use the screen with a raspberry pi 2 model b+. It worked out of the box with a python driver but I am having trouble to get it to work with lcdproc! It will be very helpful if there are some instructions on that topic (i.e. which driver to use, pin mapping etc).

[Why do you tag such a posting as SPAM?!] It's pretty easy to use with the new liquid crystal code (1.2.1), available at bitbucket dot org slash fmalpartida slash new-liquidcrystal slash wiki slash Home The critical code is: LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // LiquidCrystal_I2C lcd(i2c_addr, en, rw, rs, d4, d5, d6, d7, BACKLIGHT_PIN, POSITIVE); lcd.begin(20,4,LCD_5x8DOTS); // initialize the lcd lcd.print("Hello, ARDUINO ");

I eventually got this LCD working on the Leonardo with the following . h file which i obtained at arduino-info.wikispaces.com/file/detail/LiquidCrystal_I2C2004V1.zip does anybody know if this is the latest file available as t was posted in 2012.

The setup call in the example code needs to be changed to the following for the sketch to work with the Malpartida Liquid_Crystall_I2C library. LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Set the LCD I2C address //LiquidCrystal_I2C lcd(i2c_addr, en, rw, rs, d4, d5, d6, d7, BACKLIGHT_PIN, POSITIVE); // Set the LCD I2C address Also change the lcd.begin call to the following. lcd.begin(20, 4, LCD_5x8DOTS); // initialize the lcd Hopes this helps people.

I had to use an updated LiquidCrystal_I2C library because the older library they have linked doesn't work with the latest editor. Also, I used the I2C scanning program (google for it) and found that the LCD device address was 0x27, which when you shift to the left by one bit, resolves to 0x4E or 0x4F. Seems like they may have changed the device address to 0x4F in the last year. Unfortunately, even after figuring that out, the LCD now powers up but I can't seem to write anything to the display. Still working on that part.

Bill was spot on - seems like a good device, but as it usually goes, code and examples don't work. I am still trying to get this thing going. I wish vendors would pay more attention to details rather than just trying to sell stuff. Not very happy at all.

It took me a while to figure this out. I am new to arduino and LCDs so it is expected to be harder. I am using an arduino uno. My problem was figuring out the pins. I found numerous examples that showed different pins used. Ultimately, I followed Eric's example from above and used the I2C scanner and then tested out the various pin locations until I the LCD was recognized. Like Eric, the software came up with the address 0x3F so that has to be changed in the code sample. The BYTE keyword is no longer valid, but to make the code sample above work, simply delete the word BYTE and the comma that precedes it where ever you see it. Lastly, make sure that you download and install the custom library and header files LiquidCrystal_I2C. The link is below the sample code above called LCD2004. Look on the arduino site for instructions for how to install custom libraries if you need help on that. For the UNO, connect the pins as follows: LCD -- UNO SDA - A4 SCL - A5 VCC - 5V GND - GND Works like a charm.

Worked great, using only 2 wires is very nice. The I2C address wrong in the docs, but I ran the I2C scanner from the Arduino website and it showed the address as 0x3F, plugged that into the examples an everything worked perfectly. Thank you! Nice looking LCD.

Can someone please document how this thing works?? It seems like a nice product, but there isn't a PDF available explaining how it works. The sample code only helps so much and only if you are using Arduino.

I2C interface, this permits interfacing with only two wires (SDA/SCL) plus ground and 5-volts.SainSmart.com provides its own version of the Arduino LiquidCrystal library and some example code for this particular board. They are not of much help, but it is a nice display, though.