I2C LCD INTERFACING
In this project we will learn how to minimize the interfacing pin of 16×2 alphanumeric LCD with Arduino using PCF8574P ic.
PCF8574P ic: This IC is a silicon CMOS circuit. It provides general purpose I/O expansion for most of the microcontroller families via I2C bus. The device consists of an 8-bit quasi-bidirectional port and an I2C bus interface. The IC has low current consumption and includes latched outputs with high current drive capability.
SYMBOL | PIN | DESCRIPTION
|
A0 | 1 | address input 0 |
A1 | 2 | address input 1 |
A2 | 3 | address input 2 |
P0 | 4 | Quasi-bidirectional I/O 0 |
P1 | 5 | Quasi-bidirectional I/O 1 |
P2 | 6 | Quasi-bidirectional I/O 2 |
P3 | 7 | Quasi-bidirectional I/O 3 |
VSS | 8 | Supply GRND |
P4 | 9 | Quasi-bidirectional I/O 4 |
P5 | 10 | Quasi-bidirectional I/O 5 |
P6 | 11 | Quasi-bidirectional I/O 6 |
P7 | 12 | Quasi-bidirectional I/O 7 |
13 | Interrupt output(LOW) | |
SCL | 14 | Serial clock line |
SDA | 15 | Serial data line |
VDD | 16 | Supply 5v |
This project is built with Arduino UNO, 16×2 alphanumeric LCD and PCF8574P IC. This IC helps to convert two wire data communication into 8-bit data line and control lines.
This project works in the following manners:
- When you turn ON the system the library file for LCD imported and loaded in the Arduino.
- The system will start displaying character as per the code.
COMPONENTS REQUIRED:
- Power supply.
- Arduino UNO
- PCF8574P
16×2 alphanumeric LCD
CIRCUIT CONNECTION:
According to the block diagram the controlling part is the Arduino UNO interfaces I2C based PCF8574P IC with 16×2 alpha numeric LCD the circuit are attached to it are:
- Power supply
- PCF8574P IC
- 16×2 LCD
Power Supply: Here USB is used as the power supply from the computer.
PCF8574P and 16×2 LCD: Follow the table for the connection.
PIN NO. | PCF8574P IC PINS | 16×2 LCD PINS |
1 | Address A0 | To Ground pin |
2 | Address A1 | To Ground pin |
3 | Address A2 | To Ground pin |
4 | P0 | 11 –D4 |
5 | P1 | 12 –D5 |
6 | P2 | 13 –D6 |
7 | P3 | 14 –D7 |
8 | VSS | To Ground pin |
9 | P4 | 6-EN |
10 | P5 | 5-RW |
11 | P6 | 4-RS |
12 | P7 | Not connected |
13 | Not connected | |
14 | SCL | A-5 Arduino UNO |
15 | SDA | A-4 Arduino UNO |
16 | VDD | To Vcc-5v pin |
How the Project Works:
A best written library function is available in the arduino.
It will start displaying automatically.
Search and Download code, circuit diagram from this LINK.