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.
Original part for standard LiquidCristal library.
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.
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
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.
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.
Wire diagram: contrast
Wiring diagram: i2c connection
The banded wire are the SDA, SCL pins.
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
Than I’m going to create the prototype PCB on fritzing.
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.