Go Down

Topic: 1602LCD with Sainsmart I2C (Read 1 time) previous topic - next topic


I bought a microtivity IM161 LCD Module 1602 and connected it to a Sainsmart LCD2004 I2C. I've tried addresses 0x20, 0x24 and 0x35 with SLC on A4 and SDA on A5. All I get is white boxes on the blue background when I attempt a simple hello world. Any suggestions are greatly appreciated, as I am stumped on what to try next. I downloaded the latest I2C libs. Thanks in advance...

//Compatible with the Arduino IDE 1.0
//Library version:1.1
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup()
  lcd.init();                      // initialize the lcd

  // Print a message to the LCD.
  lcd.print("Hello, world!");

void loop()


To get an I2C device working, start with the i2c_scanner : http://playground.arduino.cc/Main/I2cScanner

Are these the components you are using ?

SDA = A4, SCL = A5

Why did you download the newest I2C libs ? You should use the newest Arduino software, version 1.0.3.


Thanks for the link. When I run the test program I get:

I2C Scanner
No I2C devices found

No I2C devices found


Feb 07, 2013, 12:26 pm Last Edit: Feb 07, 2013, 01:05 pm by runningdude22 Reason: 1
Got it!!! The link you sent me led me to find the correct address, which is 0x3F. Does capitalization matter? I can't imagine it does...

Thanks so much for your kind help!


Another question, while I'm at it. I see that the LCD came with a diode and I've read that the LCD runs off of 4.2v instead of 5.

1. Will I do any damage not using a diode?
2. How would I know what kind of diode to place on the power to it if it didn't come with one?


I would suggest a resistor of 47 ... 330 ohm for the backlight.
The '0x3f' is the same as '0x3F'.

Go Up

Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

via Egeo 16
Torino, 10131