This is the description of the Java API bindings for the Servo Bricklet 2.0. General information and technical specifications for the Servo Bricklet 2.0 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 (ExampleConfiguration.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 | import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletServoV2;
public class ExampleConfiguration {
private static final String HOST = "localhost";
private static final int PORT = 4223;
// Change XYZ to the UID of your Servo Bricklet 2.0
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
BrickletServoV2 s = new BrickletServoV2(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Servo 1: Connected to port 0, period of 19.5ms, pulse width of 1 to 2ms
// and operating angle -100 to 100°
s.setDegree(0, -10000, 10000);
s.setPulseWidth(0, 1000, 2000);
s.setPeriod(0, 19500);
s.setMotionConfiguration(0, 500000, 1000,
1000); // Full velocity with slow ac-/deceleration
// Servo 2: Connected to port 5, period of 20ms, pulse width of 0.95 to 1.95ms
// and operating angle -90 to 90°
s.setDegree(5, -9000, 9000);
s.setPulseWidth(5, 950, 1950);
s.setPeriod(5, 20000);
s.setMotionConfiguration(5, 500000, 500000,
500000); // Full velocity with full ac-/deceleration
s.setPosition(0, 10000); // Set to most right position
s.setEnable(0, true);
s.setPosition(5, -9000); // Set to most left position
s.setEnable(5, true);
System.out.println("Press key to exit"); System.in.read();
s.setEnable(0, false);
s.setEnable(5, false);
ipcon.disconnect();
}
}
|
Download (ExampleCallback.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 | import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletServoV2;
import com.tinkerforge.TinkerforgeException;
public class ExampleCallback {
private static final String HOST = "localhost";
private static final int PORT = 4223;
// Change XYZ to the UID of your Servo Bricklet 2.0
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
// Note: Declare s as final, so the listener can access it
final BrickletServoV2 s = new BrickletServoV2(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT); // Connect to brickd
// Don't use device before ipcon is connected
// Use position reached callback to swing back and forth
s.addPositionReachedListener(new BrickletServoV2.PositionReachedListener() {
public void positionReached(int servoChannel, int position) {
if (position == 9000) {
System.out.println("Position: 90°, going to -90°");
try {
s.setPosition(servoChannel, -9000);
} catch(TinkerforgeException e) {
}
} else if (position == -9000) {
System.out.println("Position: -90°, going to 90°");
try {
s.setPosition(servoChannel, 9000);
} catch(TinkerforgeException e) {
}
} else {
// Can only happen if another program sets velocity
System.out.println("Error");
}
}
});
// Enable position reached callback
s.setPositionReachedCallbackConfiguration(0, true);
// Set velocity to 100°/s. This has to be smaller or equal to the
// maximum velocity of the servo you are using, otherwise the position
// reached callback will be called too early
s.setMotionConfiguration(0, 10000, 500000, 500000);
s.setPosition(0, 9000);
s.setEnable(0, true);
System.out.println("Press key to exit"); System.in.read();
s.setEnable(0, false);
ipcon.disconnect();
}
}
|
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.
Every function of the Servo Brick API that has a servo_channel parameter can
address a servo with the servo channel (0 to 9). If it is a setter function then
multiple servos can be addressed at once with a bitmask for the
servos, if the highest bit is set. For example: 1
will address servo 1,
(1 << 1) | (1 << 5) | (1 << 15)
will address servos 1 and 5.
This allows to set configurations to several
servos with one function call. It is guaranteed that the changes will take
effect in the same PWM period for all servos you specified in the bitmask.
BrickletServoV2
(String uid, IPConnection ipcon)¶Parameters: |
|
---|---|
Returns: |
|
Creates an object with the unique device ID uid
:
BrickletServoV2 servoV2 = new BrickletServoV2("YOUR_DEVICE_UID", ipcon);
This object can then be used after the IP Connection is connected.
BrickletServoV2.
getStatus
()¶Return Object: |
|
---|
Returns the status information of the Servo Bricklet 2.0.
The status includes
Please note that the position and the velocity is a snapshot of the current position and velocity of the servo in motion.
BrickletServoV2.
setEnable
(int servoChannel, boolean enable)¶Parameters: |
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Enables a servo channel (0 to 9). If a servo is enabled, the configured position, velocity, acceleration, etc. are applied immediately.
BrickletServoV2.
getEnabled
(int servoChannel)¶Parameters: |
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Returns: |
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Returns true if the specified servo channel is enabled, false otherwise.
BrickletServoV2.
setPosition
(int servoChannel, int position)¶Parameters: |
|
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Sets the position in °/100 for the specified servo channel.
The default range of the position is -9000 to 9000, but it can be specified
according to your servo with setDegree()
.
If you want to control a linear servo or RC brushless motor controller or
similar with the Servo Brick, you can also define lengths or speeds with
setDegree()
.
BrickletServoV2.
getPosition
(int servoChannel)¶Parameters: |
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---|---|
Returns: |
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Returns the position of the specified servo channel as set by setPosition()
.
BrickletServoV2.
getCurrentPosition
(int servoChannel)¶Parameters: |
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Returns: |
|
Returns the current position of the specified servo channel. This may not be the
value of setPosition()
if the servo is currently approaching a
position goal.
BrickletServoV2.
getCurrentVelocity
(int servoChannel)¶Parameters: |
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---|---|
Returns: |
|
Returns the current velocity of the specified servo channel. This may not be the
velocity specified by setMotionConfiguration()
. if the servo is
currently approaching a velocity goal.
BrickletServoV2.
setMotionConfiguration
(int servoChannel, long velocity, long acceleration, long deceleration)¶Parameters: |
|
---|
Sets the maximum velocity of the specified servo channel in °/100s as well as the acceleration and deceleration in °/100s²
With a velocity of 0 °/100s the position will be set immediately (no velocity).
With an acc-/deceleration of 0 °/100s² the velocity will be set immediately (no acc-/deceleration).
BrickletServoV2.
getMotionConfiguration
(int servoChannel)¶Parameters: |
|
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Return Object: |
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Returns the motion configuration as set by setMotionConfiguration()
.
BrickletServoV2.
setPulseWidth
(int servoChannel, long min, long max)¶Parameters: |
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Sets the minimum and maximum pulse width of the specified servo channel in µs.
Usually, servos are controlled with a PWM, whereby the length of the pulse controls the position of the servo. Every servo has different minimum and maximum pulse widths, these can be specified with this function.
If you have a datasheet for your servo that specifies the minimum and maximum pulse width, you should set the values accordingly. If your servo comes without any datasheet you have to find the values via trial and error.
Both values have a range from 1 to 65535 (unsigned 16-bit integer). The minimum must be smaller than the maximum.
The default values are 1000µs (1ms) and 2000µs (2ms) for minimum and maximum pulse width.
BrickletServoV2.
getPulseWidth
(int servoChannel)¶Parameters: |
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Return Object: |
|
Returns the minimum and maximum pulse width for the specified servo channel as set by
setPulseWidth()
.
BrickletServoV2.
setDegree
(int servoChannel, int min, int max)¶Parameters: |
|
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Sets the minimum and maximum degree for the specified servo channel (by default given as °/100).
This only specifies the abstract values between which the minimum and maximum
pulse width is scaled. For example: If you specify a pulse width of 1000µs
to 2000µs and a degree range of -90° to 90°, a call of setPosition()
with 0 will result in a pulse width of 1500µs
(-90° = 1000µs, 90° = 2000µs, etc.).
Possible usage:
setPosition()
with a resolution of cm/100. Also the velocity will
have a resolution of cm/100s and the acceleration will have a resolution of
cm/100s².setPosition()
now controls the rpm.Both values have a possible range from -32767 to 32767 (signed 16-bit integer). The minimum must be smaller than the maximum.
The default values are -9000 and 9000 for the minimum and maximum degree.
BrickletServoV2.
getDegree
(int servoChannel)¶Parameters: |
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Return Object: |
|
Returns the minimum and maximum degree for the specified servo channel as set by
setDegree()
.
BrickletServoV2.
setPeriod
(int servoChannel, long period)¶Parameters: |
|
---|
Sets the period of the specified servo channel in µs.
Usually, servos are controlled with a PWM. Different servos expect PWMs with different periods. Most servos run well with a period of about 20ms.
If your servo comes with a datasheet that specifies a period, you should set it accordingly. If you don't have a datasheet and you have no idea what the correct period is, the default value (19.5ms) will most likely work fine.
The minimum possible period is 1µs and the maximum is 1000000µs.
The default value is 19.5ms (19500µs).
BrickletServoV2.
getPeriod
(int servoChannel)¶Parameters: |
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Returns: |
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Returns the period for the specified servo channel as set by setPeriod()
.
BrickletServoV2.
getServoCurrent
(int servoChannel)¶Parameters: |
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Returns: |
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Returns the current consumption of the specified servo channel in mA.
BrickletServoV2.
setServoCurrentConfiguration
(int servoChannel, int averagingDuration)¶Parameters: |
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Sets the averaging duration of the current measurement for the specified servo channel in ms.
BrickletServoV2.
getServoCurrentConfiguration
(int servoChannel)¶Parameters: |
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Returns: |
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Returns the servo current configuration for the specified servo channel as set
by setServoCurrentConfiguration()
.
BrickletServoV2.
setInputVoltageConfiguration
(int averagingDuration)¶Parameters: |
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Sets the averaging duration of the input voltage measurement for the specified servo channel in ms.
BrickletServoV2.
getInputVoltageConfiguration
()¶Returns: |
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Returns the input voltage configuration as set by setInputVoltageConfiguration()
.
BrickletServoV2.
getOverallCurrent
()¶Returns: |
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Returns the current consumption of all servos together in mA.
BrickletServoV2.
getInputVoltage
()¶Returns: |
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Returns the input voltage in mV. The input voltage is given via the black power input connector on the Servo Brick.
BrickletServoV2.
setCurrentCalibration
(int[] offset)¶Parameters: |
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Sets an offset value (in mA) for each channel.
Note: On delivery the Servo Bricklet 2.0 is already calibrated.
BrickletServoV2.
getCurrentCalibration
()¶Returns: |
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Returns the current calibration as set by setCurrentCalibration()
.
BrickletServoV2.
getSPITFPErrorCount
()¶Return Object: |
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Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.
BrickletServoV2.
setStatusLEDConfig
(int config)¶Parameters: |
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Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.
You can also turn the LED permanently on/off or show a heartbeat.
If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.
The following constants are available for this function:
For config:
BrickletServoV2.
getStatusLEDConfig
()¶Returns: |
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Returns the configuration as set by setStatusLEDConfig()
The following constants are available for this function:
For config:
BrickletServoV2.
getChipTemperature
()¶Returns: |
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Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!
The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.
BrickletServoV2.
reset
()¶Calling this function will reset the Bricklet. All configurations will be lost.
After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!
BrickletServoV2.
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.
BrickletServoV2.
setPositionReachedCallbackConfiguration
(int servoChannel, boolean enabled)¶Parameters: |
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Enable/Disable PositionReachedListener
listener.
BrickletServoV2.
getPositionReachedCallbackConfiguration
(int servoChannel)¶Parameters: |
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Returns: |
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Returns the listener configuration as set by
setPositionReachedCallbackConfiguration()
.
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 BrickletServoV2.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.
BrickletServoV2.
PositionReachedListener
()¶This listener can be added with the addPositionReachedListener()
function.
An added listener can be removed with the removePositionReachedListener()
function.
positionReached
(int servoChannel, int position)Parameters: |
|
---|
This listener is triggered when a position set by setPosition()
is reached. If the new position matches the current position then the
listener is not triggered, because the servo didn't move.
The parameters are the servo and the position that is reached.
You can enable this listener with setPositionReachedCallbackConfiguration()
.
Note
Since we can't get any feedback from the servo, this only works if the
velocity (see setMotionConfiguration()
) is set smaller or equal to the
maximum velocity of the servo. Otherwise the servo will lag behind the
control value and the listener will be triggered too early.
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.
BrickletServoV2.
getAPIVersion
()¶Return Object: |
|
---|
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.
BrickletServoV2.
getResponseExpected
(byte functionId)¶Parameters: |
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Returns: |
|
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:
BrickletServoV2.
setResponseExpected
(byte functionId, boolean responseExpected)¶Parameters: |
|
---|
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:
BrickletServoV2.
setResponseExpectedAll
(boolean responseExpected)¶Parameters: |
|
---|
Changes the response expected flag for all setter and listener configuration functions of this device at once.
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
BrickletServoV2.
setBootloaderMode
(int mode)¶Parameters: |
|
---|---|
Returns: |
|
Sets the bootloader mode and returns the status after the requested mode change was instigated.
You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
The following constants are available for this function:
For mode:
For status:
BrickletServoV2.
getBootloaderMode
()¶Returns: |
|
---|
Returns the current bootloader mode, see setBootloaderMode()
.
The following constants are available for this function:
For mode:
BrickletServoV2.
setWriteFirmwarePointer
(long pointer)¶Parameters: |
|
---|
Sets the firmware pointer for writeFirmware()
. The pointer has
to be increased by chunks of size 64. The data is written to flash
every 4 chunks (which equals to one page of size 256).
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
BrickletServoV2.
writeFirmware
(int[] data)¶Parameters: |
|
---|---|
Returns: |
|
Writes 64 Bytes of firmware at the position as written by
setWriteFirmwarePointer()
before. The firmware is written
to flash every 4 chunks.
You can only write firmware in bootloader mode.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
BrickletServoV2.
writeUID
(long uid)¶Parameters: |
|
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Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.
We recommend that you use Brick Viewer to change the UID.
BrickletServoV2.
readUID
()¶Returns: |
|
---|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
BrickletServoV2.
DEVICE_IDENTIFIER
¶This constant is used to identify a Servo Bricklet 2.0.
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.
BrickletServoV2.
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Servo Bricklet 2.0.