NAME

Tinkerforge::BrickDC - Drives one brushed DC motor with up to 28V and 5A (peak)

CONSTANTS

DEVICE_IDENTIFIER

This constant is used to identify a DC Brick.

The get_identity() subroutine and the CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

DEVICE_DISPLAY_NAME

This constant represents the display name of a DC Brick.

CALLBACK_UNDER_VOLTAGE

This constant is used with the register_callback() subroutine to specify the CALLBACK_UNDER_VOLTAGE callback.

CALLBACK_EMERGENCY_SHUTDOWN

This constant is used with the register_callback() subroutine to specify the CALLBACK_EMERGENCY_SHUTDOWN callback.

CALLBACK_VELOCITY_REACHED

This constant is used with the register_callback() subroutine to specify the CALLBACK_VELOCITY_REACHED callback.

CALLBACK_CURRENT_VELOCITY

This constant is used with the register_callback() subroutine to specify the CALLBACK_CURRENT_VELOCITY callback.

FUNCTION_SET_VELOCITY

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_VELOCITY

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_CURRENT_VELOCITY

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_ACCELERATION

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_ACCELERATION

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_PWM_FREQUENCY

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_PWM_FREQUENCY

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_FULL_BRAKE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_STACK_INPUT_VOLTAGE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_EXTERNAL_INPUT_VOLTAGE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_CURRENT_CONSUMPTION

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_ENABLE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_DISABLE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_IS_ENABLED

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_MINIMUM_VOLTAGE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_MINIMUM_VOLTAGE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_DRIVE_MODE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_DRIVE_MODE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_CURRENT_VELOCITY_PERIOD

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_CURRENT_VELOCITY_PERIOD

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_SPITFP_BAUDRATE_CONFIG

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_SPITFP_BAUDRATE_CONFIG

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_SEND_TIMEOUT_COUNT

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_SET_SPITFP_BAUDRATE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_SPITFP_BAUDRATE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_SPITFP_ERROR_COUNT

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_ENABLE_STATUS_LED

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_DISABLE_STATUS_LED

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_IS_STATUS_LED_ENABLED

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_PROTOCOL1_BRICKLET_NAME

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_CHIP_TEMPERATURE

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_RESET

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTION_GET_IDENTITY

This constant is used with the get_response_expected(), set_response_expected() and set_response_expected_all() subroutines.

FUNCTIONS

new()

Creates an object with the unique device ID *uid* and adds it to the IP Connection *ipcon*.

set_velocity()

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 :func:`Set Acceleration`), 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 :func:`Set PWM Frequency`.

The default velocity is 0.

get_velocity()

Returns the velocity as set by :func:`Set Velocity`.

get_current_velocity()

Returns the *current* velocity of the motor. This value is different from :func:`Get Velocity` whenever the motor is currently accelerating to a goal set by :func:`Set Velocity`.

set_acceleration()

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

The default acceleration is 10000.

get_acceleration()

Returns the acceleration as set by :func:`Set Acceleration`.

set_pwm_frequency()

Sets the frequency (in Hz) of the PWM with which the motor is driven. The possible range of the frequency is 1-20000Hz. 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.

The default frequency is 15 kHz.

get_pwm_frequency()

Returns the PWM frequency (in Hz) as set by :func:`Set PWM Frequency`.

full_brake()

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 :func:`Set Velocity` with 0 if you just want to stop the motor.

get_stack_input_voltage()

Returns the stack input voltage in mV. The stack input voltage is the voltage that is supplied via the stack, i.e. it is given by a Step-Down or Step-Up Power Supply.

get_external_input_voltage()

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

If there is an external input voltage and a stack input voltage, the motor will be driven by the external input voltage. If there is only a stack voltage present, the motor will be driven by this voltage.

.. warning:: This means, if you have a high stack voltage and a low external voltage, the motor will be driven with the low external voltage. If you then remove the external connection, it will immediately be driven by the high stack voltage.

get_current_consumption()

Returns the current consumption of the motor in mA.

enable()

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

disable()

Disables the driver chip. The configurations are kept (velocity, acceleration, etc) but the motor is not driven until it is enabled again.

is_enabled()

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

set_minimum_voltage()

Sets the minimum voltage in mV, below which the :cb:`Under Voltage` callback is triggered. The minimum possible value that works with the DC Brick is 6V. You can use this function to detect the discharge of a battery that is used to drive the motor. If you have a fixed power supply, you likely do not need this functionality.

The default value is 6V.

get_minimum_voltage()

Returns the minimum voltage as set by :func:`Set Minimum Voltage`

set_drive_mode()

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 default value is 0 = Drive/Brake.

get_drive_mode()

Returns the drive mode, as set by :func:`Set Drive Mode`.

set_current_velocity_period()

Sets a period in ms with which the :cb:`Current Velocity` callback is triggered. A period of 0 turns the callback off.

The default value is 0.

get_current_velocity_period()

Returns the period as set by :func:`Set Current Velocity Period`.

set_spitfp_baudrate_config()

The SPITF protocol can be used with a dynamic baudrate. If the dynamic baudrate is enabled, the Brick will try to adapt the baudrate for the communication between Bricks and Bricklets according to the amount of data that is transferred.

The baudrate will be increased exponentially if lots of data is send/received and decreased linearly if little data is send/received.

This lowers the baudrate in applications where little data is transferred (e.g. a weather station) and increases the robustness. If there is lots of data to transfer (e.g. Thermal Imaging Bricklet) it automatically increases the baudrate as needed.

In cases where some data has to transferred as fast as possible every few seconds (e.g. RS485 Bricklet with a high baudrate but small payload) you may want to turn the dynamic baudrate off to get the highest possible performance.

The maximum value of the baudrate can be set per port with the function :func:`Set SPITFP Baudrate`. If the dynamic baudrate is disabled, the baudrate as set by :func:`Set SPITFP Baudrate` will be used statically.

The minimum dynamic baudrate has a value range of 400000 to 2000000 baud.

By default dynamic baudrate is enabled and the minimum dynamic baudrate is 400000.

.. versionadded:: 2.3.5$nbsp;(Firmware)

get_spitfp_baudrate_config()

Returns the baudrate config, see :func:`Set SPITFP Baudrate Config`.

.. versionadded:: 2.3.5$nbsp;(Firmware)

get_send_timeout_count()

Returns the timeout count for the different communication methods.

The methods 0-2 are available for all Bricks, 3-7 only for Master Bricks.

This function is mostly used for debugging during development, in normal operation the counters should nearly always stay at 0.

.. versionadded:: 2.3.3$nbsp;(Firmware)

set_spitfp_baudrate()

Sets the baudrate for a specific Bricklet port ('a' - 'd'). The baudrate can be in the range 400000 to 2000000.

If you want to increase the throughput of Bricklets you can increase the baudrate. If you get a high error count because of high interference (see :func:`Get SPITFP Error Count`) you can decrease the baudrate.

If the dynamic baudrate feature is enabled, the baudrate set by this function corresponds to the maximum baudrate (see :func:`Set SPITFP Baudrate Config`).

Regulatory testing is done with the default baudrate. If CE compatibility or similar is necessary in you applications we recommend to not change the baudrate.

The default baudrate for all ports is 1400000.

.. versionadded:: 2.3.3$nbsp;(Firmware)

get_spitfp_baudrate()

Returns the baudrate for a given Bricklet port, see :func:`Set SPITFP Baudrate`.

.. versionadded:: 2.3.3$nbsp;(Firmware)

get_spitfp_error_count()

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 Brick side. All Bricklets have a similar function that returns the errors on the Bricklet side.

.. versionadded:: 2.3.3$nbsp;(Firmware)

enable_status_led()

Enables the status LED.

The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

The default state is enabled.

.. versionadded:: 2.3.1$nbsp;(Firmware)

disable_status_led()

Disables the status LED.

The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

The default state is enabled.

.. versionadded:: 2.3.1$nbsp;(Firmware)

is_status_led_enabled()

Returns *true* if the status LED is enabled, *false* otherwise.

.. versionadded:: 2.3.1$nbsp;(Firmware)

get_protocol1_bricklet_name()

Returns the firmware and protocol version and the name of the Bricklet for a given port.

This functions sole purpose is to allow automatic flashing of v1.x.y Bricklet plugins.

get_chip_temperature()

Returns the temperature in °C/10 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 an accuracy of ±15%. Practically it is only useful as an indicator for temperature changes.

reset()

Calling this function will reset the Brick. Calling this function on a Brick inside of a stack will reset the whole stack.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

get_identity()

Returns the UID, the UID where the Brick is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be '0'-'8' (stack position).

The device identifier numbers can be found :ref:`here <device_identifier>`. |device_identifier_constant|