Category: Tech Notes

Collection of ME 8 Embedded code snippets:

• Using java.util.TimerTask and Timer – for scheduling periodic tasks (reading a sensor, checking a status etc eg

MyTimerTask myTimerTask = new MyTimerTask();
Timer timer = new Timer();
timer.schedule(myTimerTask, millisBeforeStarting, millisBetweenExecution);

• Opening a GPIO pin:

this.pin = PeripheralManager.open(this.pinId); 
this.pin.setValue(true); // true = on, false = off

• Adding an EventListener to a switch:

GPIOPinConfig config = new GPIOPinConfig(this.portId, this.pinId,
    GPIOPinConfig.DIR_INPUT_ONLY, PeripheralConfig.DEFAULT,
    GPIOPinConfig.TRIGGER_BOTH_EDGES,

this.pin = PeripheralManager.open(config);
this.pin.setInputListener(this);

… where this implements PinListener and valueChanged() method:

public void valueChanged(PinEvent event) {
    GPIOPin eventPin = event.getPeripheral();
    ...
}

• Opening an I2C device for input/output:

I2CDeviceConfig config = new I2CDeviceConfig(i2cBus, address, addressSizeBits, serialClock);
myDevice = PeripheralManager.open(config);

• Read from a UART device:

this.uart = PeripheralManager.open(UART_DEVICE_ID);
this.uart.setBaudRate(9600);

InputStream is = Channels.newInputStream(uart);
this.serialBufferedReader = new BufferedReader(new InputStreamReader(is));

• Read using Generic Connection Framework:

CommConnection conn = (CommConnection)Connector.open("comm:/dev/ttyAMA0;baudrate=9600");
InputStream inputStream = conn.openInputStream();
this.serialBufferedReader = new BufferedReader(new
    InputStreamReader(inputStream));

• Open and write to a record store:

this.store = RecordStore.openRecordStore(storeName, true);
byte[] dataBytes = data.getBytes();
recordNum = store.addRecord(dataBytes, 0, dataBytes.length);