DigitalIn
Use the DigitalIn interface to read the value of a digital input pin. The logic level is either 1 or 0.
You can use any of the numbered Arm Mbed pins as a DigitalIn.
DigitalIn class reference
| Public Member Functions | |
| DigitalIn (PinName pin) | |
| Create a DigitalIn connected to the specified pin. More... | |
| DigitalIn (PinName pin, PinMode mode) | |
| Create a DigitalIn connected to the specified pin. More... | |
| int | read () |
| Read the input, represented as 0 or 1 (int) More... | |
| void | mode (PinMode pull) |
| Set the input pin mode. More... | |
| int | is_connected () |
| Return the output setting, represented as 0 or 1 (int) More... | |
| operator int () | |
| An operator shorthand for read() More... | |
DigitalIn hello, world
/*
* Copyright (c) 2006-2020 Arm Limited and affiliates.
* SPDX-License-Identifier: Apache-2.0
*/
#include "mbed.h"
DigitalIn mypin(SW2); // change this to the button on your board
DigitalOut myled(LED1);
int main()
{
// check mypin object is initialized and connected to a pin
if (mypin.is_connected()) {
printf("mypin is connected and initialized! \n\r");
}
// Optional: set mode as PullUp/PullDown/PullNone/OpenDrain
mypin.mode(PullNone);
// press the button and see the console / led change
while (1) {
printf("mypin has value : %d \n\r", mypin.read());
myled = mypin; // toggle led based on value of button
ThisThread::sleep_for(250);
}
}
DigitalIn example
To handle an interrupt, see InterruptIn.
Examples of logical functions - boolean logic NOT, AND, OR, XOR:
/*
* Copyright (c) 2006-2020 Arm Limited and affiliates.
* SPDX-License-Identifier: Apache-2.0
*/
#include "mbed.h"
DigitalIn a(D0);
DigitalIn b(D1);
DigitalOut z_not(LED1);
DigitalOut z_and(LED2);
DigitalOut z_or(LED3);
DigitalOut z_xor(LED4);
int main()
{
while (1) {
z_not = !a;
z_and = a && b;
z_or = a || b;
z_xor = a ^ b;
}
}
Related content
- InterruptIn API reference.