Perl - Servo Bricklet 2.0

This is the description of the Perl 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 Perl API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Configuration

Download (example_configuration.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletServoV2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Servo Bricklet 2.0

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $s = Tinkerforge::BrickletServoV2->new(&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->set_degree(0, -10000, 10000);
$s->set_pulse_width(0, 1000, 2000);
$s->set_period(0, 19500);
$s->set_motion_configuration(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->set_degree(5, -9000, 9000);
$s->set_pulse_width(5, 950, 1950);
$s->set_period(5, 20000);
$s->set_motion_configuration(5, 500000, 500000,
                             500000); # Full velocity with full ac-/deceleration

$s->set_position(0, 10000); # Set to most right position
$s->set_enable(0, 1);

$s->set_position(5, -9000); # Set to most left position
$s->set_enable(5, 1);

print "Press key to exit\n";
<STDIN>;

$s->set_enable(0, 0);
$s->set_enable(5, 0);

$ipcon->disconnect();

Callback

Download (example_callback.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletServoV2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Servo Bricklet 2.0

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
our $s = Tinkerforge::BrickletServoV2->new(&UID, $ipcon); # Create device object

# Use position reached callback to swing back and forth
sub cb_position_reached
{
    my ($servo_channel, $position) = @_;

    if ($position == 9000)
    {
        print "Position: 90°, going to -90°\n";
        $s->set_position($servo_channel, -9000);
    }
    elsif ($position == -9000)
    {
        print "Position: -90°, going to 90°\n";
        $s->set_position($servo_channel, 9000);
    }
    else
    {
        print "Error\n"; # Can only happen if another program sets position
    }
}

$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected

# Register position reached callback to subroutine cb_position_reached
$s->register_callback($s->CALLBACK_POSITION_REACHED, 'cb_position_reached');

# Enable position reached callback
$s->set_position_reached_callback_configuration(0, 1);

# 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->set_motion_configuration(0, 10000, 500000, 500000);
$s->set_position(0, 9000);
$s->set_enable(0, 1);

print "Press key to exit\n";
<STDIN>;

$s->set_enable(0, 0);

$ipcon->disconnect();

API

Generally, every subroutine of the Perl bindings can report an error as Tinkerforge::Error object via croak(). The object has a get_code() and a get_message() subroutine. There are different error code:

  • Error->ALREADY_CONNECTED = 11
  • Error->NOT_CONNECTED = 12
  • Error->CONNECT_FAILED = 13
  • Error->INVALID_FUNCTION_ID = 21
  • Error->TIMEOUT = 31
  • Error->INVALID_PARAMETER = 41
  • Error->FUNCTION_NOT_SUPPORTED = 42
  • Error->UNKNOWN_ERROR = 43
  • Error->STREAM_OUT_OF_SYNC = 51
  • Error->INVALID_UID = 61
  • Error->NON_ASCII_CHAR_IN_SECRET = 71
  • Error->WRONG_DEVICE_TYPE = 81
  • Error->DEVICE_REPLACED = 82
  • Error->WRONG_RESPONSE_LENGTH = 83

All functions 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.

Basic Functions

BrickletServoV2->new($uid, $ipcon)
Parameters:
  • $uid – Type: string
  • $ipcon – Type: IPConnection
Returns:
  • $servo_v2 – Type: BrickletServoV2

Creates an object with the unique device ID $uid:

$servo_v2 = BrickletServoV2->new("YOUR_DEVICE_UID", $ipcon);

This object can then be used after the IP Connection is connected.

BrickletServoV2->get_status()
Return Array:
  • 0: @enabled – Type: [bool, ...], Length: 10
  • 1: @current_position – Type: [int, ...], Length: 10, Unit: 1/100 °, Range: ?
  • 2: @current_velocity – Type: [int, ...], Length: 10, Unit: 1/100 °/s, Range: [0 to 500000]
  • 3: @current – Type: [int, ...], Length: 10, Unit: 1 mA, Range: [0 to 216 - 1]
  • 4: $input_voltage – Type: int, Unit: 1 mV, Range: [0 to 216 - 1]

Returns the status information of the Servo Bricklet 2.0.

The status includes

  • for each channel if it is enabled or disabled,
  • for each channel the current position,
  • for each channel the current velocity,
  • for each channel the current usage and
  • the input voltage.

Please note that the position and the velocity is a snapshot of the current position and velocity of the servo in motion.

BrickletServoV2->set_enable($servo_channel, $enable)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $enable – Type: bool, Default: 0
Returns:
  • undef

Enables a servo channel (0 to 9). If a servo is enabled, the configured position, velocity, acceleration, etc. are applied immediately.

BrickletServoV2->get_enabled($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $enable – Type: bool, Default: 0

Returns true if the specified servo channel is enabled, false otherwise.

BrickletServoV2->set_position($servo_channel, $position)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $position – Type: int, Unit: 1/100 °, Range: ?
Returns:
  • undef

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 set_degree().

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 set_degree().

BrickletServoV2->get_position($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $position – Type: int, Unit: 1/100 °, Range: ?

Returns the position of the specified servo channel as set by set_position().

BrickletServoV2->get_current_position($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $position – Type: int, Unit: 1/100 °, Range: ?

Returns the current position of the specified servo channel. This may not be the value of set_position() if the servo is currently approaching a position goal.

BrickletServoV2->get_current_velocity($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $velocity – Type: int, Unit: 1/100 °/s, Range: [0 to 500000]

Returns the current velocity of the specified servo channel. This may not be the velocity specified by set_motion_configuration(). if the servo is currently approaching a velocity goal.

BrickletServoV2->set_motion_configuration($servo_channel, $velocity, $acceleration, $deceleration)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $velocity – Type: int, Unit: 1/100 °/s, Range: [0 to 500000], Default: 100000
  • $acceleration – Type: int, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000
  • $deceleration – Type: int, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000
Returns:
  • undef

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->get_motion_configuration($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Return Array:
  • 0: $velocity – Type: int, Unit: 1/100 °/s, Range: [0 to 500000], Default: 100000
  • 1: $acceleration – Type: int, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000
  • 2: $deceleration – Type: int, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000

Returns the motion configuration as set by set_motion_configuration().

BrickletServoV2->set_pulse_width($servo_channel, $min, $max)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $min – Type: int, Unit: 1 µs, Range: [0 to 232 - 1], Default: 1000
  • $max – Type: int, Unit: 1 µs, Range: [0 to 232 - 1], Default: 2000
Returns:
  • undef

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->get_pulse_width($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Return Array:
  • 0: $min – Type: int, Unit: 1 µs, Range: [0 to 232 - 1], Default: 1000
  • 1: $max – Type: int, Unit: 1 µs, Range: [0 to 232 - 1], Default: 2000

Returns the minimum and maximum pulse width for the specified servo channel as set by set_pulse_width().

BrickletServoV2->set_degree($servo_channel, $min, $max)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $min – Type: int, Unit: 1/100 °, Range: [-215 to 215 - 1], Default: -9000
  • $max – Type: int, Unit: 1/100 °, Range: [-215 to 215 - 1], Default: 9000
Returns:
  • undef

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 set_position() with 0 will result in a pulse width of 1500µs (-90° = 1000µs, 90° = 2000µs, etc.).

Possible usage:

  • The datasheet of your servo specifies a range of 200° with the middle position at 110°. In this case you can set the minimum to -9000 and the maximum to 11000.
  • You measure a range of 220° on your servo and you don't have or need a middle position. In this case you can set the minimum to 0 and the maximum to 22000.
  • You have a linear servo with a drive length of 20cm, In this case you could set the minimum to 0 and the maximum to 20000. Now you can set the Position with set_position() 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.
  • You don't care about units and just want the highest possible resolution. In this case you should set the minimum to -32767 and the maximum to 32767.
  • You have a brushless motor with a maximum speed of 10000 rpm and want to control it with a RC brushless motor controller. In this case you can set the minimum to 0 and the maximum to 10000. set_position() 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->get_degree($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Return Array:
  • 0: $min – Type: int, Unit: 1/100 °, Range: [-215 to 215 - 1], Default: -9000
  • 1: $max – Type: int, Unit: 1/100 °, Range: [-215 to 215 - 1], Default: 9000

Returns the minimum and maximum degree for the specified servo channel as set by set_degree().

BrickletServoV2->set_period($servo_channel, $period)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $period – Type: int, Unit: 1 µs, Range: [1 to 1000000], Default: 19500
Returns:
  • undef

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->get_period($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $period – Type: int, Unit: 1 µs, Range: [1 to 1000000], Default: 19500

Returns the period for the specified servo channel as set by set_period().

BrickletServoV2->get_servo_current($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $current – Type: int, Unit: 1 mA, Range: [0 to 216 - 1]

Returns the current consumption of the specified servo channel in mA.

BrickletServoV2->set_servo_current_configuration($servo_channel, $averaging_duration)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $averaging_duration – Type: int, Unit: 1 ms, Range: [1 to 255], Default: 255
Returns:
  • undef

Sets the averaging duration of the current measurement for the specified servo channel in ms.

BrickletServoV2->get_servo_current_configuration($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $averaging_duration – Type: int, Unit: 1 ms, Range: [1 to 255], Default: 255

Returns the servo current configuration for the specified servo channel as set by set_servo_current_configuration().

BrickletServoV2->set_input_voltage_configuration($averaging_duration)
Parameters:
  • $averaging_duration – Type: int, Unit: 1 ms, Range: [1 to 255], Default: 255
Returns:
  • undef

Sets the averaging duration of the input voltage measurement for the specified servo channel in ms.

BrickletServoV2->get_input_voltage_configuration()
Returns:
  • $averaging_duration – Type: int, Unit: 1 ms, Range: [1 to 255], Default: 255

Returns the input voltage configuration as set by set_input_voltage_configuration().

BrickletServoV2->get_overall_current()
Returns:
  • $current – Type: int, Unit: 1 mA, Range: [0 to 216 - 1]

Returns the current consumption of all servos together in mA.

BrickletServoV2->get_input_voltage()
Returns:
  • $voltage – Type: int, Unit: 1 mV, Range: [0 to 216 - 1]

Returns the input voltage in mV. The input voltage is given via the black power input connector on the Servo Brick.

Advanced Functions

BrickletServoV2->set_current_calibration(@offset)
Parameters:
  • @offset – Type: [int, ...], Length: 10, Unit: 1 mA, Range: [-215 to 215 - 1]
Returns:
  • undef

Sets an offset value (in mA) for each channel.

Note: On delivery the Servo Bricklet 2.0 is already calibrated.

BrickletServoV2->get_current_calibration()
Returns:
  • @offset – Type: [int, ...], Length: 10, Unit: 1 mA, Range: [-215 to 215 - 1]

Returns the current calibration as set by set_current_calibration().

BrickletServoV2->get_spitfp_error_count()
Return Array:
  • 0: $error_count_ack_checksum – Type: int, Range: [0 to 232 - 1]
  • 1: $error_count_message_checksum – Type: int, Range: [0 to 232 - 1]
  • 2: $error_count_frame – Type: int, Range: [0 to 232 - 1]
  • 3: $error_count_overflow – Type: int, Range: [0 to 232 - 1]

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

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->set_status_led_config($config)
Parameters:
  • $config – Type: int, Range: See constants, Default: 3
Returns:
  • undef

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->STATUS_LED_CONFIG_OFF = 0
  • BrickletServoV2->STATUS_LED_CONFIG_ON = 1
  • BrickletServoV2->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletServoV2->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletServoV2->get_status_led_config()
Returns:
  • $config – Type: int, Range: See constants, Default: 3

Returns the configuration as set by set_status_led_config()

The following constants are available for this function:

For $config:

  • BrickletServoV2->STATUS_LED_CONFIG_OFF = 0
  • BrickletServoV2->STATUS_LED_CONFIG_ON = 1
  • BrickletServoV2->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletServoV2->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletServoV2->get_chip_temperature()
Returns:
  • $temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

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()
Returns:
  • undef

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->get_identity()
Return Array:
  • 0: $uid – Type: string, Length: up to 8
  • 1: $connected_uid – Type: string, Length: up to 8
  • 2: $position – Type: char, Range: ['a' to 'h', 'z']
  • 3: @hardware_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]
  • 4: @firmware_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]
  • 5: $device_identifier – Type: int, Range: [0 to 216 - 1]

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.

Callback Configuration Functions

BrickletServoV2->register_callback($callback_id, $function)
Parameters:
  • $callback_id – Type: int
  • $function – Type: string
Returns:
  • undef

Registers the given $function name with the given $callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletServoV2->set_position_reached_callback_configuration($servo_channel, $enabled)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9, 215 to 33791]
  • $enabled – Type: bool, Default: 0
Returns:
  • undef

Enable/Disable CALLBACK_POSITION_REACHED callback.

BrickletServoV2->get_position_reached_callback_configuration($servo_channel)
Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
Returns:
  • $enabled – Type: bool, Default: 0

Returns the callback configuration as set by set_position_reached_callback_configuration().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function name:

sub my_callback
{
    print "@_[0]";
}

$servo_v2->register_callback(BrickletServoV2->CALLBACK_EXAMPLE, 'my_callback')

The callback function will be called from an internal thread of the IP Connection. In contrast to many other programming languages, variables are not automatically shared between threads in Perl. If you want to share a global variable between a callback function and the rest for your program it has to be marked as :shared. See the documentation of the threads::shared Perl module for more details.

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks 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->CALLBACK_POSITION_REACHED
Callback Parameters:
  • $servo_channel – Type: int, Range: [0 to 9]
  • $position – Type: int, Unit: 1/100 °, Range: ?

This callback is triggered when a position set by set_position() is reached. If the new position matches the current position then the callback is not triggered, because the servo didn't move. The parameters are the servo and the position that is reached.

You can enable this callback with set_position_reached_callback_configuration().

Note

Since we can't get any feedback from the servo, this only works if the velocity (see set_motion_configuration()) is set smaller or equal to the maximum velocity of the servo. Otherwise the servo will lag behind the control value and the callback will be triggered too early.

Virtual Functions

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->get_api_version()
Return Array:
  • 0: @api_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]

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->get_response_expected($function_id)
Parameters:
  • $function_id – Type: int, Range: See constants
Returns:
  • $response_expected – Type: bool

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 callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). 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 $function_id:

  • BrickletServoV2->FUNCTION_SET_ENABLE = 2
  • BrickletServoV2->FUNCTION_SET_POSITION = 4
  • BrickletServoV2->FUNCTION_SET_MOTION_CONFIGURATION = 8
  • BrickletServoV2->FUNCTION_SET_PULSE_WIDTH = 10
  • BrickletServoV2->FUNCTION_SET_DEGREE = 12
  • BrickletServoV2->FUNCTION_SET_PERIOD = 14
  • BrickletServoV2->FUNCTION_SET_SERVO_CURRENT_CONFIGURATION = 17
  • BrickletServoV2->FUNCTION_SET_INPUT_VOLTAGE_CONFIGURATION = 19
  • BrickletServoV2->FUNCTION_SET_CURRENT_CALIBRATION = 23
  • BrickletServoV2->FUNCTION_SET_POSITION_REACHED_CALLBACK_CONFIGURATION = 25
  • BrickletServoV2->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletServoV2->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletServoV2->FUNCTION_RESET = 243
  • BrickletServoV2->FUNCTION_WRITE_UID = 248
BrickletServoV2->set_response_expected($function_id, $response_expected)
Parameters:
  • $function_id – Type: int, Range: See constants
  • $response_expected – Type: bool
Returns:
  • undef

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 callback 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 $function_id:

  • BrickletServoV2->FUNCTION_SET_ENABLE = 2
  • BrickletServoV2->FUNCTION_SET_POSITION = 4
  • BrickletServoV2->FUNCTION_SET_MOTION_CONFIGURATION = 8
  • BrickletServoV2->FUNCTION_SET_PULSE_WIDTH = 10
  • BrickletServoV2->FUNCTION_SET_DEGREE = 12
  • BrickletServoV2->FUNCTION_SET_PERIOD = 14
  • BrickletServoV2->FUNCTION_SET_SERVO_CURRENT_CONFIGURATION = 17
  • BrickletServoV2->FUNCTION_SET_INPUT_VOLTAGE_CONFIGURATION = 19
  • BrickletServoV2->FUNCTION_SET_CURRENT_CALIBRATION = 23
  • BrickletServoV2->FUNCTION_SET_POSITION_REACHED_CALLBACK_CONFIGURATION = 25
  • BrickletServoV2->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletServoV2->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletServoV2->FUNCTION_RESET = 243
  • BrickletServoV2->FUNCTION_WRITE_UID = 248
BrickletServoV2->set_response_expected_all($response_expected)
Parameters:
  • $response_expected – Type: bool
Returns:
  • undef

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Internal Functions

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->set_bootloader_mode($mode)
Parameters:
  • $mode – Type: int, Range: See constants
Returns:
  • $status – Type: int, Range: See constants

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:

  • BrickletServoV2->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletServoV2->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletServoV2->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletServoV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletServoV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For $status:

  • BrickletServoV2->BOOTLOADER_STATUS_OK = 0
  • BrickletServoV2->BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletServoV2->BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletServoV2->BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletServoV2->BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletServoV2->BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletServoV2->get_bootloader_mode()
Returns:
  • $mode – Type: int, Range: See constants

Returns the current bootloader mode, see set_bootloader_mode().

The following constants are available for this function:

For $mode:

  • BrickletServoV2->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletServoV2->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletServoV2->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletServoV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletServoV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletServoV2->set_write_firmware_pointer($pointer)
Parameters:
  • $pointer – Type: int, Unit: 1 B, Range: [0 to 232 - 1]
Returns:
  • undef

Sets the firmware pointer for write_firmware(). 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->write_firmware(@data)
Parameters:
  • @data – Type: [int, ...], Length: 64, Range: [0 to 255]
Returns:
  • $status – Type: int, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by set_write_firmware_pointer() 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->write_uid($uid)
Parameters:
  • $uid – Type: int, Range: [0 to 232 - 1]
Returns:
  • undef

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->read_uid()
Returns:
  • $uid – Type: int, Range: [0 to 232 - 1]

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

Constants

BrickletServoV2->DEVICE_IDENTIFIER

This constant is used to identify a Servo Bricklet 2.0.

The get_identity() function and the IPConnection->CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier 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.