// We *know* that if the IO pin reads as 0, or is low, rea

d() returns zero.

//  However, if it's high, it *may* return something els

e; the only guarantee

//  is that it will be nonzero. Thus, don't test to see i

f a read() returned

//  a 1!!!

if (buttonPin.read() == 0)

    { 

      LEDPin.write(1);

sleep(1);

      LEDPin.write(0);

sleep(1);

    } 

  } 

return MRAA_SUCCESS;

} 

Additional Examples

Because this block is just a GPIO access device, the existing MRAA GPIO

examples can be used with it.

Example projects in the IDE

When you create a new project in the Eclipse IDE, it will offer you the option

of several starter projects. Some of them, noted above, are good examples

of using the MRAA GPIO functions. They’re more complex than what we’ve

provided here, however.

For full documentation of the C++ API for GPIO pins, please visit the official

MRAA documentation.

Resources and Going Further

Pin Map

You might have noticed that we used GP46 in hardware and GPIO 32 in

our example code. This is because the MRAA library uses a different

number for the pins. If you would like to use MRAA to control hardware,

figure out which GPIO pins you plan to use on the table below (labeled

“Edison Pin”) and then use the MRAA Number in software.

The available pins on the Pi Block have been highlighted in yellow in the

table.

Notes:

• Input/output voltage on the Pi Block is 3.3V

• Input/output voltage on the GPIO Block is 3.3V by default

• Input/output voltage on the Arduino Breakout is 5V

• Input/output voltage on the Mini Breadboard is 1.8V

MRAA pin map table based on Intel’s IOT Dev Kit Repository

Edison

Pin

(Linux)

Arduino

Breakout

Mini

Breakout

MRAA

Number

Pinmode0

Pinmode1

Pinmode2

GP12

3

J18-7

20

GPIO-12

PWM0

GP13

5

J18-1

14

GPIO-13

PWM1

GP14

A4

J19-9

36

GPIO-14

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