PortOut

Table of Contents

  1. Hello World!
  2. API
  3. Interface
  4. Related

The PortOut interface is used to write to an underlying GPIO port as one value. This is much faster than BusOut as you can write a port in one go, but much less flexible as you are constrained by the port and bit layout of the underlying GPIO ports.

A mask can be supplied so only certain bits of a port are used, allowing other bits to be used for other interfaces.

Hello World!

» Import this program
PortOut_HelloWorld - main.cpp

// Toggle all four LEDs
 
#include "mbed.h"
 
// LED1 = P1.18  LED2 = P1.20  LED3 = P1.21  LED4 = P1.23
#define LED_MASK 0x00B40000
 
PortOut ledport(Port1, LED_MASK);
 
int main() {
    while(1) {
        ledport = LED_MASK;
        wait(1);
        ledport = 0;
        wait(1);
    }
}

API

» Import latest build into a program
mbed - PortOut Class Reference

Public Member Functions

  PortOut (PortName port, int mask=0xFFFFFFFF)
  Create an PortOut , connected to the specified port.
void  write (int value)
  Write the value to the output port.
int  read ()
  Read the value currently output on the port.
PortOut &  operator= (int value)
  A shorthand for write()
  operator int ()
  A shorthand for read()

Interface

The PortOut Interface can use any pins with a blue label, as long as they are in the same GPIO port.

/media/uploads/chris/pinout-thumbnails.jpg
See the Pinout page for more details


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Last modified 22 Feb 2013, by user Emilio Monti. 0 comments

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