This is my first arduino project and I need help. I have the Arduino Mega 2560 and the I2C/TWI LCD2004 Module from dfrobot. I wired it up just like shown in the diagram. When I plugged in my mega via the usb port the lcd lights up, but no characters. I then added the files needed to my library (.h, .cpp,.o), compiled and uploaded the I2C_LCD2004_Sample.pde to my mega and I get the leds flashing on the mega as it is uploading and the lcd still shows nothing, the lcd stays lit up but no characters on the screen. How do I know if I'm doing something wrong or if my LCD screen is defective? Any and all advice would be greatly appreciated.
I have GND connected to GND
VCC to 5v
SCL to analog In 5
SDA to analog in 4
I have it connected to analog 4 and 5, 5v and gnd just like the OP. I am using an Arduino Uno. Anything special I should know before I contact the seller? I tried switching the data lines, adjusted the pot, even tried some different library files. The blue backlight comes on but no text is displayed.
I was using the wrong library. I downloaded the library per the ebay ad and it didn't work. I tried several others. Finally, I went to DFRobot and downloaded the library on their product page here - I2C 16x2(1602) LCD Display Module for Arduino - DFRobot
My board doesn't say DFRobot on the back, it says YwRobot - but this is the only library that works.