Character LCD I2c Adapter
I’m going to explain a connection schema for a character display i2c adapter.
In my original post (Instructables) I create a connection schema not for the original library, but now I’m going to explain and show a schema for original one.
![](https://mischianti.org/wp-content/uploads/2019/01/FJ1OTSFJHQJPJXP.LARGE1_.jpg)
Original part for standard LiquidCristal library.
![](https://mischianti.org/wp-content/uploads/2019/02/image-10.png)
Here the IC AliExpress
You can find an adaper on the net, quite inexpensive but if you wont create a personal one you can use mine.
![](https://mischianti.org/wp-content/uploads/2019/01/FP6RI2OJB3ZV2S7.LARGE1_.jpg)
You can find the component for the original library from Aliexpress under here, you can select Display or with adapter, display or only adapter.
Wiring diagram: Back Light
![](https://mischianti.org/wp-content/uploads/2019/01/FMFC62ZJB3ZV2X7.LARGE1_.jpg)
In the wiring diagram I connect the P7 of pcf8574 on an NPN (2N2222) transistor to enable/disable backlight.
Wiring diagram: address
You can define the address of the device with A0, A1, A2 pins.
![](https://mischianti.org/wp-content/uploads/2019/01/F7LWGNCJB3ZV2WN.LARGE1_.jpg)
I set the address all low (you can connect It as you need, in the datasheet you can find all configuration).
![](https://mischianti.org/wp-content/uploads/2019/01/FP0S0NGJB6U4JDR.LARGE1_.jpg)
I find very useful sketch that search all i2c component attached, use this to check address.
Wire diagram: contrast
![](https://mischianti.org/wp-content/uploads/2019/01/FIVZCB7JB3ZV2XU.LARGE1_.jpg)
Wiring diagram: i2c connection
The banded wire are the SDA, SCL pins.
![](https://mischianti.org/wp-content/uploads/2019/01/F034J8AJB3ZV2XT.LARGE1_.jpg)
Wiring Diagram: Transfer Data
The other P1-P6 are used to transfer data to the LCD.
Prototyping PCB
First I test It on the breadboard
![](https://mischianti.org/wp-content/uploads/2019/01/F976LBFJC6K3589.LARGE1_.jpg)
Than I’m going to create the prototype PCB on fritzing.
![](https://mischianti.org/wp-content/uploads/2019/01/SchemaLCD_i2c_standardv03_pcb-1024x594.png)
Prefored board
But first (time ago) I create a board on prefored one.
It’s not so beatiful but It’s work.
Milling PCB
With my old CNC, I milled a PCB.
But the photo is the old version of PCB the tipe that works with my forket library, but now I attach the new PCB.
From the schema I create a PCB and I try to mill PCB with my router, search my guide How to milling PCB and How to build a CNC if you are interesting.
GCode files
File to use for CNC Milling.
Gerber file
File that can be used to send a schema to a factory to create a board.
Etching file
I’m not use this technic, but a lot of people love It.