Mistake on this page?
Report an issue in GitHub or email us

BusInOut

BusInOut class hierarchy

Use the BusInOut interface as a bidirectional bus that supports up to 16 DigitalInOut pins that you can read and write as one value.

You can use any of the numbered Arm Mbed pins as a DigitalInOut.

Tip:

The order of pins in the constructor is the reverse order of the pins in the byte order. If you have BusInOut(a,b,c,d,e,f,g,h), then the order of bits in the byte is hgfedcba with a being bit 0, b being bit 1, c being bit 2 and so on.

BusInOut class reference

Public Member Functions
 BusInOut (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)
 Create an BusInOut, connected to the specified pins. More...
 BusInOut (PinName pins[16])
 Create an BusInOut, connected to the specified pins. More...
void write (int value)
 Write the value to the output bus. More...
int read ()
 Read the value currently output on the bus. More...
void output ()
 Set all the pins in bus as output. More...
void input ()
 Set all the pins in bus as an input. More...
void mode (PinMode pull)
 Set the input pin mode for all the pins in bus. More...
int mask ()
 Binary mask of bus pins connected to actual pins (not NC pins) If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1. More...
BusInOutoperator= (int v)
 A shorthand for write() More...
DigitalInOutoperator[] (int index)
 Access to particular bit in random-iterator fashion. More...
 operator int ()
 A shorthand for read() More...

BusInOut Hello World!

/* mbed Example Program
 * Copyright (c) 2006-2014 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "mbed.h"
 
BusInOut pins(D0, D1, D2);
 
int main() {
    while(1) {
        pins.output();
        pins = 0x3;
        wait(1);
        pins.input();
        wait(1);
        if(pins == 0x6) {
            printf("Hello!\n");
        }
    }
}
Important Information for this Arm website

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies. If you are not happy with the use of these cookies, please review our Cookie Policy to learn how they can be disabled. By disabling cookies, some features of the site will not work.