This content relates to a deprecated version of Mbed

Mbed 2 is now deprecated. For the latest version please see the Mbed OS documentation.

For the latest PortIn API, please see PortIn.

The PortIn interface is used to read an underlying GPIO port as one value. This is much faster than BusIn as you can read 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 program

00001 // Switch on an LED if any of mbed pins 21-26 is high
00003 #include "mbed.h"
00005 PortIn     p(Port2, 0x0000003F);   // p21-p26
00006 DigitalOut ind(LED4);
00008 int main() {
00009     while(1) {
00010         int pins = p.read();
00011         if(pins) {
00012             ind = 1;
00013         } else {
00014             ind = 0;
00015         }
00016     }
00017 }


Import librarymbed

No documentation found.


The PortIn Interface can use any pin with a blue label, as long as all the pins used are in the same GPIO port

See the Pinout page for more details

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