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.
|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|
|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|
|SCL||14||Serial clock line|
|SDA||15||Serial data line|
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.
- Power supply.
- Arduino UNO
16×2 alphanumeric LCD
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|
|8||VSS||To Ground pin|
|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.