@Test
public void testTriggerLow() throws InterruptedException {
provider.setMockState(MockPin.DIGITAL_INPUT_PIN, PinState.HIGH);
provider.setMockState(MockPin.DIGITAL_INPUT_PIN, PinState.LOW);
// wait before continuing test
Thread.sleep(50);
// verify that the output pin state is low
assertEquals(PinState.LOW, outputPin.getState());
}
/**
* [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();
}