Tuesday, October 16, 2012

I2C LCD

I am done with buying cheap LCDs and trying to make them work. Last week I found an I2C LCD on ebay (named something like YwRobot LCM1602 IIC Arduino compatible) and I figured since it only needs a couple of wires to be used, I can give it a try. And it worked great!

Well not quite from the start, since I thought it needs 3.3V but after I switched it to 5V, it worked like a breeze. The library I used is LiquidCrystal_I2C (I found it here) - it is not compatible with Arduino 1.0 but I still have 0022 installed so no problem. Apparently, there is another library named fmalpartida/new-liquidcrystal that works with 1.0 but I haven't tried it yet - it looks like I would need to remove the library that comes with Arduino 1.0 and replace it with this one, I may try it someday.

Connecting to the Arduino is very easy:

  • GND to GND
  • VCC to +5V
  • SDA to analog pin 4
  • SCL to analog pin 5

    The next step is to use this LCD with my Raspberry Pi but if I understand this correctly, the LCD working at 5V and the Pi I2C pins working at 3.3V I need to be careful, I think I will wait until this board is back in stock at Adafruit.
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