Introduction: Character LCD I2c Adapter (I2c Connection Example)

About: Software developer but I love electronics, wood, nature, and everything else as well.

I'm doing a connection schema for a character display i2c adapter.

Check the updates on my site.

Now I add olso a wiring connection schema to use original library not my forked.

LiquidCrystal Arduino library for the character LCD displays, forked project for create a personal schema to learn pcf8574.

In the github project you can find schema, photo and library code.

Here a video of milled PCB derived from Fritzing breadboard schema.

Step 1: Part for Original Library

You can find the component for the original library (not my forked) from eBay.

Now here you can find the same connection schema that have same behavior.

Step 2: Wiring Diagram: Back Light

As you can see in the wiring diagram I connect to P7 an NPN (2N2222) transistor to enable/disable backlight.

Step 3: Wiring Diagram: Address

I set the address all low (you can connect It as you need, in the datasheet you can find all configuration).

I find very useful sketch that search all i2c component attached, use this to check address.

Step 4: Wire Diagram: Trimmer

To select correct contrast you need to add a 10k trimmer.

Step 5: Wiring Diagram: Transfer Data

Blue and yellow wire is to send data to device, I don't connect the device as original library so I must fork the lib and add some change.

Step 6: Change to the Original Lib

As you can see in the image I shift some bit (right to left), and on right bit I put fixed declaration of Enable, RW, Register Select, and Back light pin.

If you want you can reconvert the schema to the original. If I find some time I'm going to do It for you (and test It) so you can use original library.

Step 7: Original Lib and Connection Schema

I recreate connection schema of original library, so you can use standard library with this.

Step 8: Wire Diagram: SDA SCL

Banded wire is the SDA SCL pin of my arduino.

Step 9: Wire Diagram

As you can see the wiring diagram is quite simple, than I try to create It on prototype board of the schema.

Step 10: Prototype Board

It's not so beatiful but It's work.

Step 11: Milling PCB

From the schema I create a PCB and I try to mill PCB with my router (I'm starting a guide how to mill PCB).

Step 12: Thanks