PCA9538 I2C IO Expander

Cookbook » PCA9538 I2C IO Expander

This 8-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 2.3-V to 5.5-V VCC operation. It provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL), serial data (SDA)].

Features

Low Standby Current Consumption of 1 µA Max
I2C to Parallel Port Expander
Open-Drain Active-Low Interrupt Output
Active-Low Reset Input
Operating Power-Supply Voltage Range of 2.3 V to 5.5 V
5-V Tolerant I/O Ports
400-kHz Fast I2C Bus
Two Hardware Address Pins Allow up to Four Devices on the I2C/SMBus
Input/Output Configuration Register
Polarity Inversion Register
Noise Filter on SCL/SDA Inputs

Datasheet

#include "mbed.h"
#include "PCA9538.h"

//PCA9538 MyExpand(p9,p10,0x70,p21);
DigitalOut myled(LED1);
DigitalOut myled2(LED2);
PCA9538PinOut myled3(exp_p4,p9,p10,0x70);
PCA9538PinOut myled4(exp_p7,p9,p10,0x70);
PCA9538PinIn  mypuls(exp_p0,p9,p10,0x70);
//void vISRExpand(void);

int main() {
    //MyExpand.vInit(0x0F,&vISRExpand);
    //MyExpand.vWrite(0x00);
    while(1) {
        if(mypuls==0){
            myled2=1;
            wait(0.3);
            myled2=0;
            wait(0.3);
        }else{
            myled3=1;
            myled4=1;
            myled=myled3;
            wait(0.5);
            myled = 0;
            myled3=0;
            myled4=0;
            wait(0.5);
        }
    }
}


/*void vISRExpand(void){

    myled2=!myled2;
    MyExpand.vWrite(MyExpand.cRead()<<4);
}*/