Mbed OS 2 and Mbed OS 5

This is the handbook for Mbed OS 2. If you’re working with Mbed OS 5, please see the Mbed OS 5 documentation. For the latest BusOut API, please see BusOut.

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

Hello World!

Import program

00001 /* mbed Example Program
00002  * Copyright (c) 2006-2014 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "mbed.h"
00018 BusOut myleds(LED1, LED2, LED3, LED4);
00020 int main() {
00021     while(1) {
00022         for(int i=0; i<16; i++) {
00023             myleds = i;
00024             wait(0.25);
00025         }
00026     }
00027 }


API summary

Import library

Public Member Functions

  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)
  Create an BusOut , connected to the specified pins.
  BusOut (PinName pins[16])
  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.
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.
BusOut operator= (int v)
  A shorthand for write()
DigitalOut operator[] (int index)
  Access to particular bit in random-iterator fashion.
  operator int ()
  A shorthand for read()

Private Member Functions

  MBED_DEPRECATED ("Invalid copy construction of a NonCopyable resource.") NonCopyable(const NonCopyable &)
  NonCopyable copy constructor.
  MBED_DEPRECATED ("Invalid copy assignment of a NonCopyable resource.") NonCopyable &operator
  NonCopyable copy assignment operator.


The BusOut Interface can be used on any pin with a blue label, and also with the on-board LEDs (LED1-LED4)

The BusOut Interface can be used to set the state of the output pin, and also read back the current output state. Set the BusOut to zero to turn it off, or 1 to turn it on.

See the Pinout page for more details