Python - Performance DC Bricklet

This is the description of the Python API bindings for the Performance DC Bricklet. General information and technical specifications for the Performance DC Bricklet are summarized in its hardware description.

An installation guide for the Python API bindings is part of their general description.

Examples

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

Configuration

Download (example_configuration.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Performance DC Bricklet

import time

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_performance_dc import BrickletPerformanceDC

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    pdc = BrickletPerformanceDC(UID, ipcon) # Create device object

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

    pdc.set_drive_mode(pdc.DRIVE_MODE_DRIVE_COAST)
    pdc.set_pwm_frequency(10000) # Use PWM frequency of 10 kHz
    pdc.set_motion(4096, 4096) # Slow ac-/deceleration (12.5 %/s)
    pdc.set_velocity(32767) # Full speed forward (100 %)
    pdc.set_enabled(True) # Enable motor power

    input("Press key to exit\n") # Use raw_input() in Python 2

    # Stop motor before disabling motor power
    pdc.set_motion(4096, 16384) # Fast decceleration (50 %/s) for stopping
    pdc.set_velocity(0) # Request motor stop
    time.sleep(2) # Wait for motor to actually stop: velocity (100 %) / decceleration (50 %/s) = 2 s
    pdc.set_enabled(False) # Disable motor power

    ipcon.disconnect()

Callback

Download (example_callback.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Performance DC Bricklet

import time

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_performance_dc import BrickletPerformanceDC

# Use velocity reached callback to swing back and forth
# between full speed forward and full speed backward
def cb_velocity_reached(velocity):
    if velocity == 32767:
        print('Velocity: Full speed forward, now turning backward')
        pdc.set_velocity(-32767)
    elif velocity == -32767:
        print('Velocity: Full speed backward, now turning forward')
        pdc.set_velocity(32767)
    else:
        print('Error') # Can only happen if another program sets velocity

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    pdc = BrickletPerformanceDC(UID, ipcon) # Create device object

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

    # Register velocity reached callback to function cb_velocity_reached
    pdc.register_callback(pdc.CALLBACK_VELOCITY_REACHED, cb_velocity_reached)

    # Enable velocity reached callback
    pdc.set_velocity_reached_callback_configuration(True)

    # The acceleration has to be smaller or equal to the maximum
    # acceleration of the DC motor, otherwise the velocity reached
    # callback will be called too early
    pdc.set_motion(4096, 4096) # Slow acceleration (12.5 %/s)
    pdc.set_velocity(32767) # Full speed forward (100 %)

    # Enable motor power
    pdc.set_enabled(True)

    input("Press key to exit\n") # Use raw_input() in Python 2

    # Stop motor before disabling motor power
    pdc.set_motion(4096, 16384) # Fast decceleration (50 %/s) for stopping
    pdc.set_velocity(0) # Request motor stop
    time.sleep(2) # Wait for motor to actually stop: velocity (100 %) / decceleration (50 %/s) = 2 s
    pdc.set_enabled(False) # Disable motor power

    ipcon.disconnect()

API

Generally, every function of the Python bindings can throw an tinkerforge.ip_connection.Error exception that has a value and a description property. value can have different values:

  • Error.TIMEOUT = -1
  • Error.NOT_ADDED = -6 (unused since Python bindings version 2.0.0)
  • Error.ALREADY_CONNECTED = -7
  • Error.NOT_CONNECTED = -8
  • Error.INVALID_PARAMETER = -9
  • Error.NOT_SUPPORTED = -10
  • Error.UNKNOWN_ERROR_CODE = -11
  • Error.STREAM_OUT_OF_SYNC = -12
  • Error.INVALID_UID = -13
  • Error.NON_ASCII_CHAR_IN_SECRET = -14
  • Error.WRONG_DEVICE_TYPE = -15
  • Error.DEVICE_REPLACED = -16
  • Error.WRONG_RESPONSE_LENGTH = -17

All functions listed below are thread-safe.

Basic Functions

BrickletPerformanceDC(uid, ipcon)
Parameters:
  • uid – Type: str
  • ipcon – Type: IPConnection
Returns:
  • performance_dc – Type: BrickletPerformanceDC

Creates an object with the unique device ID uid:

performance_dc = BrickletPerformanceDC("YOUR_DEVICE_UID", ipcon)

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

BrickletPerformanceDC.set_enabled(enabled)
Parameters:
  • enabled – Type: bool
Returns:
  • None

Enables/Disables the driver chip. The driver parameters can be configured (velocity, acceleration, etc) before it is enabled.

BrickletPerformanceDC.get_enabled()
Returns:
  • enabled – Type: bool, Default: False

Returns true if the driver chip is enabled, false otherwise.

BrickletPerformanceDC.set_velocity(velocity)
Parameters:
  • velocity – Type: int, Unit: 100/32767 %, Range: [-215 + 1 to 215 - 1], Default: 0
Returns:
  • None

Sets the velocity of the motor. Whereas -32767 is full speed backward, 0 is stop and 32767 is full speed forward. Depending on the acceleration (see set_motion()), the motor is not immediately brought to the velocity but smoothly accelerated.

The velocity describes the duty cycle of the PWM with which the motor is controlled, e.g. a velocity of 3277 sets a PWM with a 10% duty cycle. You can not only control the duty cycle of the PWM but also the frequency, see set_pwm_frequency().

BrickletPerformanceDC.get_velocity()
Returns:
  • velocity – Type: int, Unit: 100/32767 %, Range: [-215 + 1 to 215 - 1], Default: 0

Returns the velocity as set by set_velocity().

BrickletPerformanceDC.get_current_velocity()
Returns:
  • velocity – Type: int, Unit: 100/32767 %, Range: [-215 + 1 to 215 - 1], Default: 0

Returns the current velocity of the motor. This value is different from get_velocity() whenever the motor is currently accelerating to a goal set by set_velocity().

BrickletPerformanceDC.set_motion(acceleration, deceleration)
Parameters:
  • acceleration – Type: int, Unit: 100/32767 %/s, Range: [0 to 216 - 1], Default: 10000
  • deceleration – Type: int, Unit: 100/32767 %/s, Range: [0 to 216 - 1], Default: 10000
Returns:
  • None

Sets the acceleration and deceleration of the motor. It is given in velocity/s. An acceleration of 10000 means, that every second the velocity is increased by 10000 (or about 30% duty cycle).

For example: If the current velocity is 0 and you want to accelerate to a velocity of 16000 (about 50% duty cycle) in 10 seconds, you should set an acceleration of 1600.

If acceleration and deceleration is set to 0, there is no speed ramping, i.e. a new velocity is immediately given to the motor.

BrickletPerformanceDC.get_motion()
Return Object:
  • acceleration – Type: int, Unit: 100/32767 %/s, Range: [0 to 216 - 1], Default: 10000
  • deceleration – Type: int, Unit: 100/32767 %/s, Range: [0 to 216 - 1], Default: 10000

Returns the acceleration/deceleration as set by set_motion().

BrickletPerformanceDC.full_brake()
Returns:
  • None

Executes an active full brake.

Warning

This function is for emergency purposes, where an immediate brake is necessary. Depending on the current velocity and the strength of the motor, a full brake can be quite violent.

Call set_velocity() with 0 if you just want to stop the motor.

BrickletPerformanceDC.get_pwm_frequency()
Returns:
  • frequency – Type: int, Unit: 1 Hz, Range: [1 to 20000], Default: 15000

Returns the PWM frequency as set by set_pwm_frequency().

BrickletPerformanceDC.get_power_statistics()
Return Object:
  • voltage – Type: int, Unit: 1 mV, Range: [0 to 216 - 1]
  • current – Type: int, Unit: 1 mA, Range: [0 to 216 - 1]
  • temperature – Type: int, Unit: 1/10 °, Range: [-215 to 215 - 1]

Returns input voltage, current usage and temperature of the driver.

BrickletPerformanceDC.set_thermal_shutdown(temperature)
Parameters:
  • temperature – Type: int, Unit: 1 °, Range: [0 to 255], Default: 125
Returns:
  • None

Sets a temperature threshold that is used for thermal shutdown.

Additionally to this user defined threshold the driver chip will shut down at a temperature of 150°C.

If a thermal shutdown is triggered the driver is disabled and has to be explicitly re-enabled with set_enabled().

BrickletPerformanceDC.get_thermal_shutdown()
Returns:
  • temperature – Type: int, Unit: 1 °, Range: [0 to 255]

Returns the thermal shutdown temperature as set by set_thermal_shutdown().

BrickletPerformanceDC.set_gpio_configuration(channel, debounce, stop_deceleration)
Parameters:
  • channel – Type: int, Range: [0 to 1]
  • debounce – Type: int, Unit: 1 ms, Range: [0 to 216 - 1], Default: 200
  • stop_deceleration – Type: int, Unit: 100/32767 %/s, Range: [0 to 216 - 1], Default: 216 - 1
Returns:
  • None

Sets the GPIO configuration for the given channel. You can configure a debounce and the deceleration that is used if the action is configured as normal stop. See set_gpio_action().

BrickletPerformanceDC.get_gpio_configuration(channel)
Parameters:
  • channel – Type: int, Range: [0 to 1]
Return Object:
  • debounce – Type: int, Unit: 1 ms, Range: [0 to 216 - 1], Default: 200
  • stop_deceleration – Type: int, Unit: 100/32767 %/s, Range: [0 to 216 - 1], Default: 216 - 1

Returns the GPIO configuration for a channel as set by set_gpio_configuration().

BrickletPerformanceDC.set_gpio_action(channel, action)
Parameters:
  • channel – Type: int, Range: [0 to 1]
  • action – Type: int, Range: See constants, Default: 0
Returns:
  • None

Sets the GPIO action for the given channel.

The action can be a normal stop, a full brake or a callback. Each for a rising edge or falling edge. The actions are a bitmask they can be used at the same time. You can for example trigger a full brake and a callback at the same time or for rising and falling edge.

The deceleration speed for the normal stop can be configured with set_gpio_configuration().

The following constants are available for this function:

For action:

  • BrickletPerformanceDC.GPIO_ACTION_NONE = 0
  • BrickletPerformanceDC.GPIO_ACTION_NORMAL_STOP_RISING_EDGE = 1
  • BrickletPerformanceDC.GPIO_ACTION_NORMAL_STOP_FALLING_EDGE = 2
  • BrickletPerformanceDC.GPIO_ACTION_FULL_BRAKE_RISING_EDGE = 4
  • BrickletPerformanceDC.GPIO_ACTION_FULL_BRAKE_FALLING_EDGE = 8
  • BrickletPerformanceDC.GPIO_ACTION_CALLBACK_RISING_EDGE = 16
  • BrickletPerformanceDC.GPIO_ACTION_CALLBACK_FALLING_EDGE = 32
BrickletPerformanceDC.get_gpio_action(channel)
Parameters:
  • channel – Type: int, Range: [0 to 1]
Returns:
  • action – Type: int, Range: See constants, Default: 0

Returns the GPIO action for a channel as set by set_gpio_action().

The following constants are available for this function:

For action:

  • BrickletPerformanceDC.GPIO_ACTION_NONE = 0
  • BrickletPerformanceDC.GPIO_ACTION_NORMAL_STOP_RISING_EDGE = 1
  • BrickletPerformanceDC.GPIO_ACTION_NORMAL_STOP_FALLING_EDGE = 2
  • BrickletPerformanceDC.GPIO_ACTION_FULL_BRAKE_RISING_EDGE = 4
  • BrickletPerformanceDC.GPIO_ACTION_FULL_BRAKE_FALLING_EDGE = 8
  • BrickletPerformanceDC.GPIO_ACTION_CALLBACK_RISING_EDGE = 16
  • BrickletPerformanceDC.GPIO_ACTION_CALLBACK_FALLING_EDGE = 32
BrickletPerformanceDC.get_gpio_state()
Returns:
  • gpio_state – Type: [bool, ...], Length: 2

Returns the GPIO state for both channels. True if the state is high and false if the state is low.

Advanced Functions

BrickletPerformanceDC.set_drive_mode(mode)
Parameters:
  • mode – Type: int, Range: See constants, Default: 0
Returns:
  • None

Sets the drive mode. Possible modes are:

  • 0 = Drive/Brake
  • 1 = Drive/Coast

These modes are different kinds of motor controls.

In Drive/Brake mode, the motor is always either driving or braking. There is no freewheeling. Advantages are: A more linear correlation between PWM and velocity, more exact accelerations and the possibility to drive with slower velocities.

In Drive/Coast mode, the motor is always either driving or freewheeling. Advantages are: Less current consumption and less demands on the motor and driver chip.

The following constants are available for this function:

For mode:

  • BrickletPerformanceDC.DRIVE_MODE_DRIVE_BRAKE = 0
  • BrickletPerformanceDC.DRIVE_MODE_DRIVE_COAST = 1
BrickletPerformanceDC.get_drive_mode()
Returns:
  • mode – Type: int, Range: See constants, Default: 0

Returns the drive mode, as set by set_drive_mode().

The following constants are available for this function:

For mode:

  • BrickletPerformanceDC.DRIVE_MODE_DRIVE_BRAKE = 0
  • BrickletPerformanceDC.DRIVE_MODE_DRIVE_COAST = 1
BrickletPerformanceDC.set_pwm_frequency(frequency)
Parameters:
  • frequency – Type: int, Unit: 1 Hz, Range: [1 to 20000], Default: 15000
Returns:
  • None

Sets the frequency of the PWM with which the motor is driven. Often a high frequency is less noisy and the motor runs smoother. However, with a low frequency there are less switches and therefore fewer switching losses. Also with most motors lower frequencies enable higher torque.

If you have no idea what all this means, just ignore this function and use the default frequency, it will very likely work fine.

BrickletPerformanceDC.set_error_led_config(config)
Parameters:
  • config – Type: int, Range: See constants, Default: 3
Returns:
  • None

Configures the error LED to be either turned off, turned on, blink in heartbeat mode or show an error.

If the LED is configured to show errors it has three different states:

  • Off: No error present.
  • 1s interval blinking: Input voltage too low (below 6V).
  • 250ms interval blinking: Overtemperature or overcurrent.

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.ERROR_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.ERROR_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.ERROR_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.ERROR_LED_CONFIG_SHOW_ERROR = 3
BrickletPerformanceDC.get_error_led_config()
Returns:
  • config – Type: int, Range: See constants, Default: 3

Returns the LED configuration as set by set_error_led_config()

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.ERROR_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.ERROR_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.ERROR_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.ERROR_LED_CONFIG_SHOW_ERROR = 3
BrickletPerformanceDC.set_cw_led_config(config)
Parameters:
  • config – Type: int, Range: See constants, Default: 3
Returns:
  • None

Configures the CW LED to be either turned off, turned on, blink in heartbeat mode or if the motor turn clockwise.

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.CW_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.CW_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.CW_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.CW_LED_CONFIG_SHOW_CW_AS_FORWARD = 3
  • BrickletPerformanceDC.CW_LED_CONFIG_SHOW_CW_AS_BACKWARD = 4
BrickletPerformanceDC.get_cw_led_config()
Returns:
  • config – Type: int, Range: See constants, Default: 3

Returns the LED configuration as set by set_cw_led_config()

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.CW_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.CW_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.CW_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.CW_LED_CONFIG_SHOW_CW_AS_FORWARD = 3
  • BrickletPerformanceDC.CW_LED_CONFIG_SHOW_CW_AS_BACKWARD = 4
BrickletPerformanceDC.set_ccw_led_config(config)
Parameters:
  • config – Type: int, Range: See constants, Default: 3
Returns:
  • None

Configures the CCW LED to be either turned off, turned on, blink in heartbeat mode or if the motor turn counter-clockwise.

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.CCW_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.CCW_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.CCW_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.CCW_LED_CONFIG_SHOW_CCW_AS_FORWARD = 3
  • BrickletPerformanceDC.CCW_LED_CONFIG_SHOW_CCW_AS_BACKWARD = 4
BrickletPerformanceDC.get_ccw_led_config()
Returns:
  • config – Type: int, Range: See constants, Default: 3

Returns the LED configuration as set by set_ccw_led_config()

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.CCW_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.CCW_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.CCW_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.CCW_LED_CONFIG_SHOW_CCW_AS_FORWARD = 3
  • BrickletPerformanceDC.CCW_LED_CONFIG_SHOW_CCW_AS_BACKWARD = 4
BrickletPerformanceDC.set_gpio_led_config(channel, config)
Parameters:
  • channel – Type: int, Range: [0 to 1]
  • config – Type: int, Range: See constants, Default: 4
Returns:
  • None

Configures the GPIO LED to be either turned off, turned on, blink in heartbeat mode or the GPIO state.

The GPIO LED can be configured for both channels.

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.GPIO_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.GPIO_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.GPIO_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.GPIO_LED_CONFIG_SHOW_GPIO_ACTIVE_HIGH = 3
  • BrickletPerformanceDC.GPIO_LED_CONFIG_SHOW_GPIO_ACTIVE_LOW = 4
BrickletPerformanceDC.get_gpio_led_config(channel)
Parameters:
  • channel – Type: int, Range: [0 to 1]
Returns:
  • config – Type: int, Range: See constants, Default: 4

Returns the LED configuration as set by set_gpio_led_config()

The following constants are available for this function:

For config:

  • BrickletPerformanceDC.GPIO_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.GPIO_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.GPIO_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.GPIO_LED_CONFIG_SHOW_GPIO_ACTIVE_HIGH = 3
  • BrickletPerformanceDC.GPIO_LED_CONFIG_SHOW_GPIO_ACTIVE_LOW = 4
BrickletPerformanceDC.get_spitfp_error_count()
Return Object:
  • error_count_ack_checksum – Type: int, Range: [0 to 232 - 1]
  • error_count_message_checksum – Type: int, Range: [0 to 232 - 1]
  • error_count_frame – Type: int, Range: [0 to 232 - 1]
  • 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.

BrickletPerformanceDC.set_status_led_config(config)
Parameters:
  • config – Type: int, Range: See constants, Default: 3
Returns:
  • None

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:

  • BrickletPerformanceDC.STATUS_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.STATUS_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletPerformanceDC.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:

  • BrickletPerformanceDC.STATUS_LED_CONFIG_OFF = 0
  • BrickletPerformanceDC.STATUS_LED_CONFIG_ON = 1
  • BrickletPerformanceDC.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletPerformanceDC.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletPerformanceDC.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.

BrickletPerformanceDC.reset()
Returns:
  • None

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!

BrickletPerformanceDC.get_identity()
Return Object:
  • uid – Type: str, Length: up to 8
  • connected_uid – Type: str, Length: up to 8
  • position – Type: chr, Range: ["a" to "h", "z"]
  • 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]
  • 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]
  • 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

BrickletPerformanceDC.register_callback(callback_id, function)
Parameters:
  • callback_id – Type: int
  • function – Type: callable
Returns:
  • None

Registers the given function with the given callback_id.

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

BrickletPerformanceDC.set_emergency_shutdown_callback_configuration(enabled)
Parameters:
  • enabled – Type: bool, Default: False
Returns:
  • None

Enable/Disable CALLBACK_EMERGENCY_SHUTDOWN callback.

BrickletPerformanceDC.get_emergency_shutdown_callback_configuration()
Returns:
  • enabled – Type: bool, Default: True

Returns the callback configuration as set by set_emergency_shutdown_callback_configuration().

BrickletPerformanceDC.set_velocity_reached_callback_configuration(enabled)
Parameters:
  • enabled – Type: bool, Default: False
Returns:
  • None

Enable/Disable CALLBACK_VELOCITY_REACHED callback.

BrickletPerformanceDC.get_velocity_reached_callback_configuration()
Returns:
  • enabled – Type: bool, Default: False

Returns the callback configuration as set by set_velocity_reached_callback_configuration().

BrickletPerformanceDC.set_current_velocity_callback_configuration(period, value_has_to_change)
Parameters:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: False
Returns:
  • None

The period is the period with which the CALLBACK_CURRENT_VELOCITY callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

BrickletPerformanceDC.get_current_velocity_callback_configuration()
Return Object:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value_has_to_change – Type: bool, Default: False

Returns the callback configuration as set by set_current_velocity_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:

def my_callback(param):
    print(param)

performance_dc.register_callback(BrickletPerformanceDC.CALLBACK_EXAMPLE, my_callback)

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.

BrickletPerformanceDC.CALLBACK_EMERGENCY_SHUTDOWN
Callback Parameters:
  • no parameters

This callback is triggered if either the current consumption is too high or the temperature of the driver chip is too high (above 150°C) or the user defined thermal shutdown is triggered (see set_thermal_shutdown()). n case of a voltage below 6V (input voltage) this callback is triggered as well.

If this callback is triggered, the driver chip gets disabled at the same time. That means, set_enabled() has to be called to drive the motor again.

BrickletPerformanceDC.CALLBACK_VELOCITY_REACHED
Callback Parameters:
  • velocity – Type: int, Unit: 100/32767 %, Range: [-215 + 1 to 215 - 1]

This callback is triggered whenever a set velocity is reached. For example: If a velocity of 0 is present, acceleration is set to 5000 and velocity to 10000, the CALLBACK_VELOCITY_REACHED callback will be triggered after about 2 seconds, when the set velocity is actually reached.

Note

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

BrickletPerformanceDC.CALLBACK_CURRENT_VELOCITY
Callback Parameters:
  • velocity – Type: int, Unit: 100/32767 %, Range: [-215 + 1 to 215 - 1]

This callback is triggered with the period that is set by set_current_velocity_callback_configuration(). The parameter is the current velocity used by the motor.

The CALLBACK_CURRENT_VELOCITY callback is only triggered after the set period if there is a change in the velocity.

BrickletPerformanceDC.CALLBACK_GPIO_STATE
Callback Parameters:
  • gpio_state – Type: [bool, ...], Length: 2

This callback is triggered by GPIO changes if it is activated through set_gpio_action().

New in version 2.0.1 (Plugin).

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.

BrickletPerformanceDC.get_api_version()
Return Object:
  • 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.

BrickletPerformanceDC.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:

  • BrickletPerformanceDC.FUNCTION_SET_ENABLED = 1
  • BrickletPerformanceDC.FUNCTION_SET_VELOCITY = 3
  • BrickletPerformanceDC.FUNCTION_SET_MOTION = 6
  • BrickletPerformanceDC.FUNCTION_FULL_BRAKE = 8
  • BrickletPerformanceDC.FUNCTION_SET_DRIVE_MODE = 9
  • BrickletPerformanceDC.FUNCTION_SET_PWM_FREQUENCY = 11
  • BrickletPerformanceDC.FUNCTION_SET_THERMAL_SHUTDOWN = 14
  • BrickletPerformanceDC.FUNCTION_SET_GPIO_CONFIGURATION = 16
  • BrickletPerformanceDC.FUNCTION_SET_GPIO_ACTION = 18
  • BrickletPerformanceDC.FUNCTION_SET_ERROR_LED_CONFIG = 21
  • BrickletPerformanceDC.FUNCTION_SET_CW_LED_CONFIG = 23
  • BrickletPerformanceDC.FUNCTION_SET_CCW_LED_CONFIG = 25
  • BrickletPerformanceDC.FUNCTION_SET_GPIO_LED_CONFIG = 27
  • BrickletPerformanceDC.FUNCTION_SET_EMERGENCY_SHUTDOWN_CALLBACK_CONFIGURATION = 29
  • BrickletPerformanceDC.FUNCTION_SET_VELOCITY_REACHED_CALLBACK_CONFIGURATION = 31
  • BrickletPerformanceDC.FUNCTION_SET_CURRENT_VELOCITY_CALLBACK_CONFIGURATION = 33
  • BrickletPerformanceDC.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletPerformanceDC.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletPerformanceDC.FUNCTION_RESET = 243
  • BrickletPerformanceDC.FUNCTION_WRITE_UID = 248
BrickletPerformanceDC.set_response_expected(function_id, response_expected)
Parameters:
  • function_id – Type: int, Range: See constants
  • response_expected – Type: bool
Returns:
  • None

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:

  • BrickletPerformanceDC.FUNCTION_SET_ENABLED = 1
  • BrickletPerformanceDC.FUNCTION_SET_VELOCITY = 3
  • BrickletPerformanceDC.FUNCTION_SET_MOTION = 6
  • BrickletPerformanceDC.FUNCTION_FULL_BRAKE = 8
  • BrickletPerformanceDC.FUNCTION_SET_DRIVE_MODE = 9
  • BrickletPerformanceDC.FUNCTION_SET_PWM_FREQUENCY = 11
  • BrickletPerformanceDC.FUNCTION_SET_THERMAL_SHUTDOWN = 14
  • BrickletPerformanceDC.FUNCTION_SET_GPIO_CONFIGURATION = 16
  • BrickletPerformanceDC.FUNCTION_SET_GPIO_ACTION = 18
  • BrickletPerformanceDC.FUNCTION_SET_ERROR_LED_CONFIG = 21
  • BrickletPerformanceDC.FUNCTION_SET_CW_LED_CONFIG = 23
  • BrickletPerformanceDC.FUNCTION_SET_CCW_LED_CONFIG = 25
  • BrickletPerformanceDC.FUNCTION_SET_GPIO_LED_CONFIG = 27
  • BrickletPerformanceDC.FUNCTION_SET_EMERGENCY_SHUTDOWN_CALLBACK_CONFIGURATION = 29
  • BrickletPerformanceDC.FUNCTION_SET_VELOCITY_REACHED_CALLBACK_CONFIGURATION = 31
  • BrickletPerformanceDC.FUNCTION_SET_CURRENT_VELOCITY_CALLBACK_CONFIGURATION = 33
  • BrickletPerformanceDC.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletPerformanceDC.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletPerformanceDC.FUNCTION_RESET = 243
  • BrickletPerformanceDC.FUNCTION_WRITE_UID = 248
BrickletPerformanceDC.set_response_expected_all(response_expected)
Parameters:
  • response_expected – Type: bool
Returns:
  • None

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.

BrickletPerformanceDC.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:

  • BrickletPerformanceDC.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletPerformanceDC.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletPerformanceDC.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletPerformanceDC.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletPerformanceDC.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For status:

  • BrickletPerformanceDC.BOOTLOADER_STATUS_OK = 0
  • BrickletPerformanceDC.BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletPerformanceDC.BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletPerformanceDC.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletPerformanceDC.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletPerformanceDC.BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletPerformanceDC.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:

  • BrickletPerformanceDC.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletPerformanceDC.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletPerformanceDC.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletPerformanceDC.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletPerformanceDC.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletPerformanceDC.set_write_firmware_pointer(pointer)
Parameters:
  • pointer – Type: int, Unit: 1 B, Range: [0 to 232 - 1]
Returns:
  • None

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.

BrickletPerformanceDC.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.

BrickletPerformanceDC.write_uid(uid)
Parameters:
  • uid – Type: int, Range: [0 to 232 - 1]
Returns:
  • None

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.

BrickletPerformanceDC.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

BrickletPerformanceDC.DEVICE_IDENTIFIER

This constant is used to identify a Performance DC Bricklet.

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.

BrickletPerformanceDC.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Performance DC Bricklet.