Gibberish data on 16x2 LCD Display with PCF8574T backpack

I am a complete beginner in Arduino ( But with a passion to learn) and I have been breaking my head to solve my problem with LCD 16X2.

I double checked my connections and the code. I have a LCD 16216-9SL ( Oriole - Indian Make. http://www.orioleindia.com/lcd%20manual/16x2.pdf) and a PCF8574T (Phillips/NXP) Back pack.

I downloaded and installed the latest libraries (1.3.4) as mentioned and complied my code. But my display wont show anything. It occasionally shows gibberish data, some times blank, some times some Japanese script like characters.

I am unable to figure out what is wrong. The backlight goes on and off. But nothing on the display. Please find the bizzare LCD behaviour -

https://drive.google.com/file/d/0B2YR0_EiA5BxSldYa1RmQTVxOFE/view?usp=sharing https://drive.google.com/file/d/0B2YR0_EiA5BxYmhQV1Y5NlF4aVU/view?usp=sharing

While checking the data sheet of 16216 LCD, I see the pin configurations are different. Can someone please help me

Your photos show an I2C adapter with soldered header. And a 16x2 display which is NOT soldered to the backpack.

Solder the pins and everything should work fine. From the photo, it looks as if your I2C address is 0x27.

David.

You haven’t specified which I2C library you are using. The current recommendation is to use the ‘New LiquidCrystal’ library by Francisco Malpartida. The library itself can be found here and an important explanation about how to install and use it is here.

You might want to look at this tutorial as one of the displays that Terry uses looks similar to yours. This tutorial uses the above mentioned library.

The ‘data sheet’ that you have linked to does not match the device in your photograph. The device in your photograph looks like just about every other display out there and the one in the data sheet is similar except they have doubled up on the GND pins and omitted pin 16.

Don

floresta: The 'data sheet' that you have linked to does not match the device in your photograph. The device in your photograph looks like just about every other display out there and the one in the data sheet is similar except they have doubled up on the GND pins and omitted pin 16.

Certainly not the same.

Makes sense of course, as pin 16 is ground as well as pin 1, you can use pin 1 for both grounds and save one pin - but what you have is the normal - 16 pin - variant.