This is the description of the Java API bindings for the LCD 16x2 Bricklet. General information and technical specifications for the LCD 16x2 Bricklet are summarized in its hardware description.
An installation guide for the Java API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
Download (ExampleHelloWorld.java)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletLCD16x2;
public class ExampleHelloWorld {
private static final String HOST = "localhost";
private static final int PORT = 4223;
// Change XYZ to the UID of your LCD 16x2 Bricklet
private static final String UID = "XYZ";
// 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
BrickletLCD16x2 lcd = new BrickletLCD16x2(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Turn backlight on
lcd.backlightOn();
// Write "Hello World"
lcd.writeLine((short)0, (short)0, "Hello World");
System.out.println("Press key to exit"); System.in.read();
ipcon.disconnect();
}
}
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Download (ExampleButtonCallback.java)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletLCD16x2;
public class ExampleButtonCallback {
private static final String HOST = "localhost";
private static final int PORT = 4223;
// Change XYZ to the UID of your LCD 16x2 Bricklet
private static final String UID = "XYZ";
// 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
BrickletLCD16x2 lcd = new BrickletLCD16x2(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Add button pressed listener
lcd.addButtonPressedListener(new BrickletLCD16x2.ButtonPressedListener() {
public void buttonPressed(short button) {
System.out.println("Button Pressed: " + button);
}
});
// Add button released listener
lcd.addButtonReleasedListener(new BrickletLCD16x2.ButtonReleasedListener() {
public void buttonReleased(short button) {
System.out.println("Button Released: " + button);
}
});
System.out.println("Press key to exit"); System.in.read();
ipcon.disconnect();
}
}
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Download (ExampleUnicode.java)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 | import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletLCD16x2;
public class ExampleUnicode {
private static final String HOST = "localhost";
private static final int PORT = 4223;
// Change XYZ to the UID of your LCD 16x2 Bricklet
private static final String UID = "XYZ";
// Maps a normal UTF-16 encoded string to the LCD charset
static String utf16ToKS0066U(String utf16)
{
String ks0066u = "";
char c;
for (int i = 0; i < utf16.length(); i++) {
int codePoint = utf16.codePointAt(i);
if (Character.isHighSurrogate(utf16.charAt(i))) {
// Skip low surrogate
i++;
}
// ASCII subset from JIS X 0201
if (codePoint >= 0x0020 && codePoint <= 0x007e) {
// The LCD charset doesn't include '\' and '~', use similar characters instead
switch (codePoint) {
case 0x005c: c = (char)0xa4; break; // REVERSE SOLIDUS maps to IDEOGRAPHIC COMMA
case 0x007e: c = (char)0x2d; break; // TILDE maps to HYPHEN-MINUS
default: c = (char)codePoint; break;
}
}
// Katakana subset from JIS X 0201
else if (codePoint >= 0xff61 && codePoint <= 0xff9f) {
c = (char)(codePoint - 0xfec0);
}
// Special characters
else {
switch (codePoint) {
case 0x00a5: c = (char)0x5c; break; // YEN SIGN
case 0x2192: c = (char)0x7e; break; // RIGHTWARDS ARROW
case 0x2190: c = (char)0x7f; break; // LEFTWARDS ARROW
case 0x00b0: c = (char)0xdf; break; // DEGREE SIGN maps to KATAKANA SEMI-VOICED SOUND MARK
case 0x03b1: c = (char)0xe0; break; // GREEK SMALL LETTER ALPHA
case 0x00c4: c = (char)0xe1; break; // LATIN CAPITAL LETTER A WITH DIAERESIS
case 0x00e4: c = (char)0xe1; break; // LATIN SMALL LETTER A WITH DIAERESIS
case 0x00df: c = (char)0xe2; break; // LATIN SMALL LETTER SHARP S
case 0x03b5: c = (char)0xe3; break; // GREEK SMALL LETTER EPSILON
case 0x00b5: c = (char)0xe4; break; // MICRO SIGN
case 0x03bc: c = (char)0xe4; break; // GREEK SMALL LETTER MU
case 0x03c2: c = (char)0xe5; break; // GREEK SMALL LETTER FINAL SIGMA
case 0x03c1: c = (char)0xe6; break; // GREEK SMALL LETTER RHO
case 0x221a: c = (char)0xe8; break; // SQUARE ROOT
case 0x00b9: c = (char)0xe9; break; // SUPERSCRIPT ONE maps to SUPERSCRIPT (minus) ONE
case 0x00a4: c = (char)0xeb; break; // CURRENCY SIGN
case 0x00a2: c = (char)0xec; break; // CENT SIGN
case 0x2c60: c = (char)0xed; break; // LATIN CAPITAL LETTER L WITH DOUBLE BAR
case 0x00f1: c = (char)0xee; break; // LATIN SMALL LETTER N WITH TILDE
case 0x00d6: c = (char)0xef; break; // LATIN CAPITAL LETTER O WITH DIAERESIS
case 0x00f6: c = (char)0xef; break; // LATIN SMALL LETTER O WITH DIAERESIS
case 0x03f4: c = (char)0xf2; break; // GREEK CAPITAL THETA SYMBOL
case 0x221e: c = (char)0xf3; break; // INFINITY
case 0x03a9: c = (char)0xf4; break; // GREEK CAPITAL LETTER OMEGA
case 0x00dc: c = (char)0xf5; break; // LATIN CAPITAL LETTER U WITH DIAERESIS
case 0x00fc: c = (char)0xf5; break; // LATIN SMALL LETTER U WITH DIAERESIS
case 0x03a3: c = (char)0xf6; break; // GREEK CAPITAL LETTER SIGMA
case 0x03c0: c = (char)0xf7; break; // GREEK SMALL LETTER PI
case 0x0304: c = (char)0xf8; break; // COMBINING MACRON
case 0x00f7: c = (char)0xfd; break; // DIVISION SIGN
default:
case 0x25a0: c = (char)0xff; break; // BLACK SQUARE
}
}
// Special handling for 'x' followed by COMBINING MACRON
if (c == (char)0xf8) {
if (!ks0066u.endsWith("x")) {
c = (char)0xff; // BLACK SQUARE
}
if (ks0066u.length() > 0) {
ks0066u = ks0066u.substring(0, ks0066u.length() - 1);
}
}
ks0066u += c;
}
return ks0066u;
}
// 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
BrickletLCD16x2 lcd = new BrickletLCD16x2(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Turn backlight on
lcd.backlightOn();
// Write a string using the utf16ToKS0066U function to map to the LCD charset
lcd.writeLine((short)0, (short)0, utf16ToKS0066U("Stromstärke: 5µA"));
// Write a string directly including characters from the LCD charset
lcd.writeLine((short)1, (short)0, "Drehzahl: 1000s\u00e9");
System.out.println("Press key to exit"); System.in.read();
ipcon.disconnect();
}
}
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Generally, every method of the Java bindings that returns a value can
throw a TimeoutException
. This exception gets thrown if the
device did not respond. If a cable based connection is used, it is
unlikely that this exception gets thrown (assuming nobody unplugs the
device). However, if a wireless connection is used, timeouts will occur
if the distance to the device gets too big.
Beside the TimeoutException
there is also a NotConnectedException
that
is thrown if a method needs to communicate with the device while the
IP Connection is not connected.
Since Java does not support multiple return values and return by reference is not possible for primitive types, we use small classes that only consist of member variables. The member variables of the returned objects are described in the corresponding method descriptions.
The package for all Brick/Bricklet bindings and the IP Connection is
com.tinkerforge.*
All methods listed below are thread-safe.
BrickletLCD16x2
(String uid, IPConnection ipcon)¶Parameters: |
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Returns: |
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Creates an object with the unique device ID uid
:
BrickletLCD16x2 lcd16x2 = new BrickletLCD16x2("YOUR_DEVICE_UID", ipcon);
This object can then be used after the IP Connection is connected.
BrickletLCD16x2.
writeLine
(short line, short position, String text)¶Parameters: |
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Writes text to a specific line with a specific position. The text can have a maximum of 16 characters.
For example: (0, 5, "Hello") will write Hello in the middle of the first line of the display.
The display uses a special charset that includes all ASCII characters except backslash and tilde. The LCD charset also includes several other non-ASCII characters, see the charset specification for details. The Unicode example above shows how to specify non-ASCII characters and how to translate from Unicode to the LCD charset.
BrickletLCD16x2.
clearDisplay
()¶Deletes all characters from the display.
BrickletLCD16x2.
backlightOn
()¶Turns the backlight on.
BrickletLCD16x2.
backlightOff
()¶Turns the backlight off.
BrickletLCD16x2.
isBacklightOn
()¶Returns: |
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Returns true if the backlight is on and false otherwise.
BrickletLCD16x2.
setConfig
(boolean cursor, boolean blinking)¶Parameters: |
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Configures if the cursor (shown as "_") should be visible and if it
should be blinking (shown as a blinking block). The cursor position
is one character behind the the last text written with
writeLine()
.
BrickletLCD16x2.
getConfig
()¶Return Object: |
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Returns the configuration as set by setConfig()
.
BrickletLCD16x2.
isButtonPressed
(short button)¶Parameters: |
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Returns: |
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Returns true if the button is pressed.
If you want to react on button presses and releases it is recommended to use the
ButtonPressedListener
and ButtonReleasedListener
listeners.
BrickletLCD16x2.
setCustomCharacter
(short index, short[] character)¶Parameters: |
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The LCD 16x2 Bricklet can store up to 8 custom characters. The characters consist of 5x8 pixels and can be addressed with the index 0-7. To describe the pixels, the first 5 bits of 8 bytes are used. For example, to make a custom character "H", you should transfer the following:
character[0] = 0b00010001
(decimal value 17)character[1] = 0b00010001
(decimal value 17)character[2] = 0b00010001
(decimal value 17)character[3] = 0b00011111
(decimal value 31)character[4] = 0b00010001
(decimal value 17)character[5] = 0b00010001
(decimal value 17)character[6] = 0b00010001
(decimal value 17)character[7] = 0b00000000
(decimal value 0)The characters can later be written with writeLine()
by using the
characters with the byte representation 8 ("\x08" or "\u0008") to 15
("\x0F" or "\u000F").
You can play around with the custom characters in Brick Viewer since version 2.0.1.
Custom characters are stored by the LCD in RAM, so they have to be set after each startup.
New in version 2.0.1 (Plugin).
BrickletLCD16x2.
getCustomCharacter
(short index)¶Parameters: |
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Returns: |
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Returns the custom character for a given index, as set with
setCustomCharacter()
.
New in version 2.0.1 (Plugin).
BrickletLCD16x2.
getIdentity
()¶Return Object: |
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Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
Listeners can be registered to receive
time critical or recurring data from the device. The registration is done
with add*Listener()
functions of the device object.
The parameter is a listener class object, for example:
device.addExampleListener(new BrickletLCD16x2.ExampleListener() {
public void property(int value) {
System.out.println("Value: " + value);
}
});
The available listener classes with inherent methods to be overwritten
are described below. It is possible to add several listeners and
to remove them with the corresponding remove*Listener()
function.
Note
Using listeners for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.
BrickletLCD16x2.
ButtonPressedListener
()¶This listener can be added with the addButtonPressedListener()
function.
An added listener can be removed with the removeButtonPressedListener()
function.
buttonPressed
(short button)Parameters: |
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This listener is triggered when a button is pressed. The parameter is the number of the button.
BrickletLCD16x2.
ButtonReleasedListener
()¶This listener can be added with the addButtonReleasedListener()
function.
An added listener can be removed with the removeButtonReleasedListener()
function.
buttonReleased
(short button)Parameters: |
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This listener is triggered when a button is released. The parameter is the number of the button.
Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.
BrickletLCD16x2.
getAPIVersion
()¶Return Object: |
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Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.
BrickletLCD16x2.
getResponseExpected
(byte functionId)¶Parameters: |
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Returns: |
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Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.
For getter functions this is enabled by default and cannot be disabled,
because those functions will always send a response. For listener configuration
functions it is enabled by default too, but can be disabled by
setResponseExpected()
. For setter functions it is disabled by default
and can be enabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For functionId:
BrickletLCD16x2.
setResponseExpected
(byte functionId, boolean responseExpected)¶Parameters: |
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Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and listener configuration functions (default value: true). For getter functions it is always enabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For functionId:
BrickletLCD16x2.
setResponseExpectedAll
(boolean responseExpected)¶Parameters: |
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Changes the response expected flag for all setter and listener configuration functions of this device at once.
BrickletLCD16x2.
DEVICE_IDENTIFIER
¶This constant is used to identify a LCD 16x2 Bricklet.
The getIdentity()
function and the
IPConnection.EnumerateListener
listener of the IP Connection have a deviceIdentifier
parameter to specify
the Brick's or Bricklet's type.
BrickletLCD16x2.
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a LCD 16x2 Bricklet.