Kits / Starter Kit: Hardware Hacking / Examples / Control Mains Switches Remotely / Using Java

Control Remote Mains Switches using Java¶

For this project we are assuming, that you have a Java development environment set up and that you have a rudimentary understanding of the Java language.

If you are totally new to Java itself you should start here. If you are new to the Tinkerforge API, you should start here.

We are also assuming that you have the remote control connected to an Industrial Quad Relay Bricklet as described here.

Goals¶

The goal of this little project is to give an idea how the relays of the Industrial Quad Relay Bricklet have to be switched to turn the mains switches on/off.

The following code uses setMonoflop() to trigger a button press on the remote control. A monoflop will set a new state (relay open or close) and hold it for a given time (1.5s in the example code). After this time the previous state is restored. This approach simulates a button click that takes 1.5s (1500ms).

According to the hardware setup section the inputs of the remote control should be connected as follows:

Signal	Relay
A	0
B	1
ON	2
OFF	3

To trigger the switch "A ON" of the remote control the relays 0 and 2 of the Industrial Quad Relay Bricklet have to be closed. This is represented by the selection mask (1 << 0) | (1 << 2).

So the monoflop function should be called with this selection mask and a time of 1500ms to simulate a button press of "A ON". See the following source code for a minimal example.

Source Code¶

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletIndustrialQuadRelay;

public class RemoteSwitch {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;
    private static final String UID = "ctG"; // Change to your UID
    private static final int VALUE_A_ON  = (1 << 0) | (1 << 2); // Pin 0 and 2 high
    private static final int VALUE_A_OFF = (1 << 0) | (1 << 3); // Pin 0 and 3 high
    private static final int VALUE_B_ON  = (1 << 1) | (1 << 2); // Pin 1 and 2 high
    private static final int VALUE_B_OFF = (1 << 1) | (1 << 3); // Pin 1 and 3 high

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions you
    //       might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletIndustrialQuadRelay iqr = new BrickletIndustrialQuadRelay(UID, ipcon); // Create device object

        ipcon.connect(HOST, PORT); // Connect to brickd
        // Don't use device before ipcon is connected

        iqr.setMonoflop(VALUE_A_ON, 15, 1500); // Set pins to high for 1.5 seconds

        ipcon.disconnect();
    }
}