/**
* [ARGUMENT/OPTION "--pin (#)" | "-p (#)" ] This example program accepts an optional argument for
* specifying the GPIO pin (by number) to use with this GPIO listener example. If no argument is
* provided, then GPIO #1 will be used. -- EXAMPLE: "--pin 4" or "-p 0".
*
* <p>[ARGUMENT/OPTION "--pull (up|down|off)" | "-l (up|down|off)" | "--up" | "--down" ] This
* example program accepts an optional argument for specifying pin pull resistance. Supported
* values: "up|down" (or simply "1|0"). If no value is specified in the command argument, then the
* pin pull resistance will be set to PULL_UP by default. -- EXAMPLES: "--pull up", "-pull down",
* "--pull off", "--up", "--down", "-pull 0", "--pull 1", "-l up", "-l down".
*
* @param args
* @throws InterruptedException
* @throws PlatformAlreadyAssignedException
*/
public static void main(String[] args)
throws InterruptedException, PlatformAlreadyAssignedException {
// ####################################################################
//
// since we are not using the default Raspberry Pi platform, we should
// explicitly assign the platform as the BananaPro platform.
//
// ####################################################################
PlatformManager.setPlatform(Platform.BANANAPRO);
// create Pi4J console wrapper/helper
// (This is a utility class to abstract some of the boilerplate code)
final Console console = new Console();
// print program title/header
console.title("<-- The Pi4J Project -->", "GPIO Input Example");
// allow for user to exit program using CTRL-C
console.promptForExit();
// create gpio controller
final GpioController gpio = GpioFactory.getInstance();
// ####################################################################
//
// When provisioning a pin, use the BananaProPin class.
//
// ####################################################################
// by default we will use gpio pin #01; however, if an argument
// has been provided, then lookup the pin by address
Pin pin =
CommandArgumentParser.getPin(
BananaProPin.class, // pin provider class to obtain pin instance from
BananaProPin.GPIO_01, // default pin if no pin argument found
args); // argument array to search in
// by default we will use gpio pin PULL-UP; however, if an argument
// has been provided, then use the specified pull resistance
PinPullResistance pull =
CommandArgumentParser.getPinPullResistance(
PinPullResistance.PULL_UP, // default pin pull resistance if no pull argument found
args); // argument array to search in
// provision gpio pin as an input pin
final GpioPinDigitalInput input = gpio.provisionDigitalInputPin(pin, "MyInput", pull);
// set shutdown state for this pin: unexport the pin
input.setShutdownOptions(true);
// prompt user that we are ready
console.println("Successfully provisioned [" + pin + "] with PULL resistance = [" + pull + "]");
console.emptyLine();
console.box("The GPIO input pin states will be displayed below.");
console.emptyLine();
// display pin state
console.emptyLine();
console.println(
" ["
+ input.toString()
+ "] digital state is: "
+ ConsoleColor.conditional(
input.getState().isHigh(), // conditional expression
ConsoleColor.GREEN, // positive conditional color
ConsoleColor.RED, // negative conditional color
input.getState()));
console.emptyLine();
// stop all GPIO activity/threads by shutting down the GPIO controller
// (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
gpio.shutdown();
}
/**
* [ARGUMENT/OPTION "--pin (#)" | "-p (#)" ] This example program accepts an optional argument for
* specifying the GPIO pin (by number) to use with this GPIO listener example. If no argument is
* provided, then GPIO #1 will be used. -- EXAMPLE: "--pin 4" or "-p 0".
*
* @param args
* @throws InterruptedException
* @throws PlatformAlreadyAssignedException
*/
public static void main(String[] args)
throws InterruptedException, PlatformAlreadyAssignedException {
// ####################################################################
//
// since we are not using the default Raspberry Pi platform, we should
// explicitly assign the platform as the BananaPi platform.
//
// ####################################################################
PlatformManager.setPlatform(Platform.BANANAPI);
// create Pi4J console wrapper/helper
// (This is a utility class to abstract some of the boilerplate code)
final Console console = new Console();
// print program title/header
console.title("<-- The Pi4J Project -->", "GPIO Output Example");
// allow for user to exit program using CTRL-C
console.promptForExit();
// create gpio controller
final GpioController gpio = GpioFactory.getInstance();
// ####################################################################
//
// When provisioning a pin, use the BananaPiPin class.
//
// ####################################################################
// by default we will use gpio pin #01; however, if an argument
// has been provided, then lookup the pin by address
Pin pin =
CommandArgumentParser.getPin(
BananaPiPin.class, // pin provider class to obtain pin instance from
BananaPiPin.GPIO_01, // default pin if no pin argument found
args); // argument array to search in
// provision gpio pin as an output pin and turn on
final GpioPinDigitalOutput output =
gpio.provisionDigitalOutputPin(pin, "My Output", PinState.HIGH);
// set shutdown state for this pin: keep as output pin, set to low state
output.setShutdownOptions(false, PinState.LOW);
// create a pin listener to print out changes to the output gpio pin state
output.addListener(
new GpioPinListenerDigital() {
@Override
public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event) {
// display pin state on console
console.println(
" --> GPIO PIN STATE CHANGE: "
+ event.getPin()
+ " = "
+ ConsoleColor.conditional(
event.getState().isHigh(), // conditional expression
ConsoleColor.GREEN, // positive conditional color
ConsoleColor.RED, // negative conditional color
event.getState())); // text to display
}
});
// prompt user that we are ready
console.println(" ... Successfully provisioned output pin: " + output.toString());
console.emptyLine();
console.box("The GPIO output pin states will cycle HIGH and LOW states now.");
console.emptyLine();
// notify user of current pin state
console.println(
"--> ["
+ output.toString()
+ "] state was provisioned with state = "
+ ConsoleColor.conditional(
output.getState().isHigh(), // conditional expression
ConsoleColor.GREEN, // positive conditional color
ConsoleColor.RED, // negative conditional color
output.getState())); // text to display
// wait
Thread.sleep(500);
// --------------------------------------------------------------------------
// tset gpio pin state to LOW
console.emptyLine();
console.println("Setting output pin state is set to LOW.");
output.low(); // or ... output.setState(PinState.LOW);
// wait
Thread.sleep(500);
// --------------------------------------------------------------------------
// tset gpio pin state to HIGH
console.emptyLine();
console.println("Setting output pin state from LOW to HIGH.");
output.setState(PinState.HIGH); // or ... output.high();
// wait
Thread.sleep(500);
// --------------------------------------------------------------------------
// toggle the current state of gpio pin (from HIGH to LOW)
console.emptyLine();
console.println("Toggling output pin state from HIGH to LOW.");
output.toggle();
// wait
Thread.sleep(500);
// --------------------------------------------------------------------------
// pulse gpio pin state for 1 second HIGH and then return to LOW
console.emptyLine();
console.println("Pulsing output pin state HIGH for 1 second.");
output.pulse(1000, true); // set second argument to 'true' use a blocking call
Thread.sleep(50);
// --------------------------------------------------------------------------
// blink gpio pin state for 1 second between HIGH and LOW states
console.emptyLine();
console.println(
"Blinking output pin state between HIGH and LOW for 3 seconds with a blink rate of 250ms.");
Future future = output.blink(250, 3000);
// --------------------------------------------------------------------------
// wait for blinking to finish; we are notified in a future object
while (!future.isDone()) {
Thread.sleep(50);
}
// stop all GPIO activity/threads by shutting down the GPIO controller
// (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
gpio.shutdown();
}
