BusOut

/media/uploads/mbedofficial/digitalout_interfaces.png

The BusOut interface is used to create a number of DigitalOut pins that can be written as one value.

Hello World!

Binary counter on LEDs

#include "mbed.h"

BusOut myleds(LED1, LED2, LED3, LED4);

int main() {
    while(1) {
        for(int i=0; i<16; i++) {
            myleds = i;
            wait(0.25);
        }
    }
}

API

API summary

BusOut	A digital output bus, used for setting the state of a collection of pins
Configuration Methods
BusOut	Create an BusOut, connected to the specified pins
Access Methods
write	Write the value to the output bus
read	Read the value currently output on the bus
Access Method Shorthand
operator=	A shorthand for write
operator int()	A shorthand for read

class BusOut : public Base

A digital output bus, used for setting the state of a collection of pins

BusOut( PinName p0,
PinName p1 = NC,
PinName p2 = NC,
PinName p3 = NC,
PinName p4 = NC,
PinName p5 = NC,
PinName p6 = NC,
PinName p7 = NC,
PinName p8 = NC,
PinName p9 = NC,
PinName p10 = NC,
PinName p11 = NC,
PinName p12 = NC,
PinName p13 = NC,
PinName p14 = NC,
PinName p15 = NC,
const char * name = NULL )

Create an BusOut, connected to the specified pins

void write( int value )

Write the value to the output bus

int read()

Read the value currently output on the bus

BusOut& operator= ( int v )

A shorthand for write

operator int()

A shorthand for read

Interface

The BusOut interface can be used on mbed pins p5-p30, and also on-board LED1-LED4

The BusOut interface can be used to set the state of the output pins, and also read back the current output state.

Examples

Scroll across the LEDs

#include "mbed.h"

BusOut myleds(LED1, LED2, LED3, LED4);

int main() {
    while(1) {
        for(int i=0; i<4; i++) {
            myleds = 1 << i;
            wait(0.25);
        }
    }
}