Software / API Bindings / Go / API Reference and Examples / Bricklets / Servo Bricklet 2.0

Go - Servo Bricklet 2.0¶

This is the description of the Go 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 Go API bindings is part of their general description. Additional documentation can be found on godoc.org.

Examples¶

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

Callback¶

Download (example_callback.go)

package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/servo_v2_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Servo Bricklet 2.0.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    s, _ := servo_v2_bricklet.New(UID, &ipcon) // Create device object.

    ipcon.Connect(ADDR) // Connect to brickd.
    defer ipcon.Disconnect()
    // Don't use device before ipcon is connected.

    s.RegisterPositionReachedCallback(func(servoChannel uint16, position int16) {
        if position == 9000 {
            fmt.Println("Position: 90°, going to -90°")
            s.SetPosition(servoChannel, -9000)
        } else if position == -9000 {
            fmt.Println("Position: -90°, going to 90°")
            s.SetPosition(servoChannel, 9000)
        } else {
            // Can only happen if another program sets position
            fmt.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)

    fmt.Print("Press enter to exit.")
    fmt.Scanln()

    s.SetEnable(0, false)
}

Configuration¶

Download (example_configuration.go)

package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/servo_v2_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Servo Bricklet 2.0.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    s, _ := servo_v2_bricklet.New(UID, &ipcon) // Create device object.

    ipcon.Connect(ADDR) // Connect to brickd.
    defer ipcon.Disconnect()
    // 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)

    fmt.Print("Press enter to exit.")
    fmt.Scanln()

    s.SetEnable(0, false)
    s.SetEnable(5, false)
}

API¶

The Servo Bricklet 2.0 API is defined in the package github.com/Tinkerforge/go-api-bindings/servo_v2_bricklet

Nearly every function of the Go bindings can return an ipconnection.DeviceError, implementing the error interface. The error can have one of the following values:

ipconnection.DeviceErrorSuccess = 0
ipconnection.DeviceErrorInvalidParameter = 1
ipconnection.DeviceErrorFunctionNotSupported = 2
ipconnection.DeviceErrorUnknownError = 3

which correspond to the values returned from Bricks and Bricklets.

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¶

func servo_v2_bricklet.New(uid string, ipcon *IPConnection) (device ServoV2Bricklet, err error)¶

Parameters:	uid – Type: string ipcon – Type: *IPConnection
Returns:	device – Type: ServoV2Bricklet err – Type: error

Creates a new ServoV2Bricklet object with the unique device ID uid and adds it to the IPConnection ipcon:

device, err := servo_v2_bricklet.New("YOUR_DEVICE_UID", &ipcon)

This device object can be used after the IPConnection has been connected.

func (*ServoV2Bricklet) GetStatus() (enabled [10]bool, currentPosition [10]int16, currentVelocity [10]int16, current [10]uint16, inputVoltage uint16, err error)¶

Returns:	enabled – Type: [10]bool currentPosition – Type: [10]int16, Unit: 1/100 °, Range: ? currentVelocity – Type: [10]int16, Unit: 1/100 °/s, Range: [0 to 500000] current – Type: [10]uint16, Unit: 1 mA, Range: [0 to 2¹⁶ - 1] inputVoltage – Type: uint16, Unit: 1 mV, Range: [0 to 2¹⁶ - 1] err – Type: error

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.

func (*ServoV2Bricklet) SetEnable(servoChannel uint16, enable bool) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] enable – Type: bool, Default: false
Returns:	err – Type: error

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

func (*ServoV2Bricklet) GetEnabled(servoChannel uint16) (enable bool, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	enable – Type: bool, Default: false err – Type: error

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

func (*ServoV2Bricklet) SetPosition(servoChannel uint16, position int16) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] position – Type: int16, Unit: 1/100 °, Range: ?
Returns:	err – Type: error

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().

func (*ServoV2Bricklet) GetPosition(servoChannel uint16) (position int16, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	position – Type: int16, Unit: 1/100 °, Range: ? err – Type: error

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

func (*ServoV2Bricklet) GetCurrentPosition(servoChannel uint16) (position int16, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	position – Type: int16, Unit: 1/100 °, Range: ? err – Type: error

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.

func (*ServoV2Bricklet) GetCurrentVelocity(servoChannel uint16) (velocity uint16, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	velocity – Type: uint16, Unit: 1/100 °/s, Range: [0 to 500000] err – Type: error

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.

func (*ServoV2Bricklet) SetMotionConfiguration(servoChannel uint16, velocity uint32, acceleration uint32, deceleration uint32) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] velocity – Type: uint32, Unit: 1/100 °/s, Range: [0 to 500000], Default: 100000 acceleration – Type: uint32, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000 deceleration – Type: uint32, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000
Returns:	err – Type: error

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).

func (*ServoV2Bricklet) GetMotionConfiguration(servoChannel uint16) (velocity uint32, acceleration uint32, deceleration uint32, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	velocity – Type: uint32, Unit: 1/100 °/s, Range: [0 to 500000], Default: 100000 acceleration – Type: uint32, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000 deceleration – Type: uint32, Unit: 1/100 °/s², Range: [0 to 500000], Default: 50000 err – Type: error

Returns the motion configuration as set by SetMotionConfiguration().

func (*ServoV2Bricklet) SetPulseWidth(servoChannel uint16, min uint32, max uint32) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] min – Type: uint32, Unit: 1 µs, Range: [0 to 2³² - 1], Default: 1000 max – Type: uint32, Unit: 1 µs, Range: [0 to 2³² - 1], Default: 2000
Returns:	err – Type: error

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.

func (*ServoV2Bricklet) GetPulseWidth(servoChannel uint16) (min uint32, max uint32, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	min – Type: uint32, Unit: 1 µs, Range: [0 to 2³² - 1], Default: 1000 max – Type: uint32, Unit: 1 µs, Range: [0 to 2³² - 1], Default: 2000 err – Type: error

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

func (*ServoV2Bricklet) SetDegree(servoChannel uint16, min int16, max int16) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] min – Type: int16, Unit: 1/100 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: -9000 max – Type: int16, Unit: 1/100 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 9000
Returns:	err – Type: error

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:

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 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.
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. 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.

func (*ServoV2Bricklet) GetDegree(servoChannel uint16) (min int16, max int16, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	min – Type: int16, Unit: 1/100 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: -9000 max – Type: int16, Unit: 1/100 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 9000 err – Type: error

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

func (*ServoV2Bricklet) SetPeriod(servoChannel uint16, period uint32) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] period – Type: uint32, Unit: 1 µs, Range: [1 to 1000000], Default: 19500
Returns:	err – Type: error

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).

func (*ServoV2Bricklet) GetPeriod(servoChannel uint16) (period uint32, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	period – Type: uint32, Unit: 1 µs, Range: [1 to 1000000], Default: 19500 err – Type: error

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

func (*ServoV2Bricklet) GetServoCurrent(servoChannel uint16) (current uint16, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	current – Type: uint16, Unit: 1 mA, Range: [0 to 2¹⁶ - 1] err – Type: error

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

func (*ServoV2Bricklet) SetServoCurrentConfiguration(servoChannel uint16, averagingDuration uint8) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] averagingDuration – Type: uint8, Unit: 1 ms, Range: [1 to 255], Default: 255
Returns:	err – Type: error

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

func (*ServoV2Bricklet) GetServoCurrentConfiguration(servoChannel uint16) (averagingDuration uint8, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	averagingDuration – Type: uint8, Unit: 1 ms, Range: [1 to 255], Default: 255 err – Type: error

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

func (*ServoV2Bricklet) SetInputVoltageConfiguration(averagingDuration uint8) (err error)¶

Parameters:	averagingDuration – Type: uint8, Unit: 1 ms, Range: [1 to 255], Default: 255
Returns:	err – Type: error

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

func (*ServoV2Bricklet) GetInputVoltageConfiguration() (averagingDuration uint8, err error)¶

Returns:	averagingDuration – Type: uint8, Unit: 1 ms, Range: [1 to 255], Default: 255 err – Type: error

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

func (*ServoV2Bricklet) GetOverallCurrent() (current uint16, err error)¶

Returns:	current – Type: uint16, Unit: 1 mA, Range: [0 to 2¹⁶ - 1] err – Type: error

Returns the current consumption of all servos together in mA.

func (*ServoV2Bricklet) GetInputVoltage() (voltage uint16, err error)¶

Returns:	voltage – Type: uint16, Unit: 1 mV, Range: [0 to 2¹⁶ - 1] err – Type: error

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

Advanced Functions¶

func (*ServoV2Bricklet) SetCurrentCalibration(offset [10]int16) (err error)¶

Parameters:	offset – Type: [10]int16, Unit: 1 mA, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	err – Type: error

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

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

func (*ServoV2Bricklet) GetCurrentCalibration() (offset [10]int16, err error)¶

Returns:	offset – Type: [10]int16, Unit: 1 mA, Range: [-2¹⁵ to 2¹⁵ - 1] err – Type: error

Returns the current calibration as set by SetCurrentCalibration().

func (*ServoV2Bricklet) GetSPITFPErrorCount() (errorCountAckChecksum uint32, errorCountMessageChecksum uint32, errorCountFrame uint32, errorCountOverflow uint32, err error)¶

Returns:	errorCountAckChecksum – Type: uint32, Range: [0 to 2³² - 1] errorCountMessageChecksum – Type: uint32, Range: [0 to 2³² - 1] errorCountFrame – Type: uint32, Range: [0 to 2³² - 1] errorCountOverflow – Type: uint32, Range: [0 to 2³² - 1] err – Type: error

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.

func (*ServoV2Bricklet) SetStatusLEDConfig(config uint8) (err error)¶

Parameters:	config – Type: uint8, Range: See constants, Default: 3
Returns:	err – Type: error

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:

servo_v2_bricklet.StatusLEDConfigOff = 0
servo_v2_bricklet.StatusLEDConfigOn = 1
servo_v2_bricklet.StatusLEDConfigShowHeartbeat = 2
servo_v2_bricklet.StatusLEDConfigShowStatus = 3

func (*ServoV2Bricklet) GetStatusLEDConfig() (config uint8, err error)¶

Returns:	config – Type: uint8, Range: See constants, Default: 3 err – Type: error

Returns the configuration as set by SetStatusLEDConfig()

The following constants are available for this function:

For config:

servo_v2_bricklet.StatusLEDConfigOff = 0
servo_v2_bricklet.StatusLEDConfigOn = 1
servo_v2_bricklet.StatusLEDConfigShowHeartbeat = 2
servo_v2_bricklet.StatusLEDConfigShowStatus = 3

func (*ServoV2Bricklet) GetChipTemperature() (temperature int16, err error)¶

Returns:	temperature – Type: int16, Unit: 1 °C, Range: [-2¹⁵ to 2¹⁵ - 1] err – Type: error

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.

func (*ServoV2Bricklet) Reset() (err error)¶

Returns:	err – Type: error

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!

func (*ServoV2Bricklet) GetIdentity() (uid string, connectedUid string, position rune, hardwareVersion [3]uint8, firmwareVersion [3]uint8, deviceIdentifier uint16, err error)¶

Returns:

Returns:	uid – Type: string, Length: up to 8 connectedUid – Type: string, Length: up to 8 position – Type: rune, Range: ['a' to 'h', 'z'] hardwareVersion – Type: [3]uint8 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] firmwareVersion – Type: [3]uint8 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] deviceIdentifier – Type: uint16, Range: [0 to 2¹⁶ - 1] err – Type: error

uid – Type: string, Length: up to 8
connectedUid – Type: string, Length: up to 8
position – Type: rune, Range: ['a' to 'h', 'z']
hardwareVersion – Type: [3]uint8

0: major – Type: uint8, Range: [0 to 255]
1: minor – Type: uint8, Range: [0 to 255]
2: revision – Type: uint8, Range: [0 to 255]

firmwareVersion – Type: [3]uint8

0: major – Type: uint8, Range: [0 to 255]
1: minor – Type: uint8, Range: [0 to 255]
2: revision – Type: uint8, Range: [0 to 255]

deviceIdentifier – Type: uint16, Range: [0 to 2¹⁶ - 1]
err – Type: error

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¶

func (*ServoV2Bricklet) SetPositionReachedCallbackConfiguration(servoChannel uint16, enabled bool) (err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9, 2¹⁵ to 33791] enabled – Type: bool, Default: false
Returns:	err – Type: error

Enable/Disable PositionReachedCallback callback.

func (*ServoV2Bricklet) GetPositionReachedCallbackConfiguration(servoChannel uint16) (enabled bool, err error)¶

Parameters:	servoChannel – Type: uint16, Range: [0 to 9]
Returns:	enabled – Type: bool, Default: false err – Type: error

Returns the callback configuration as set by SetPositionReachedCallbackConfiguration().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding Register*Callback function, which returns a unique callback ID. This ID can be used to deregister the callback later with the corresponding Deregister*Callback function.

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.

func (*ServoV2Bricklet) RegisterPositionReachedCallback(func(servoChannel uint16, position int16)) (registrationId uint64)¶

Callback Parameters:	servoChannel – Type: uint16, Range: [0 to 9] position – Type: int16, Unit: 1/100 °, Range: ?
Returns:	registrationId – Type: uint64

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

You can enable this callback 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 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.

func (*ServoV2Bricklet) GetAPIVersion() (apiVersion [3]uint8, err error)¶

Returns:	apiVersion – Type: [3]uint8 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] err – Type: error

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.

func (*ServoV2Bricklet) GetResponseExpected(functionId uint8) (responseExpected bool, err error)¶

Parameters:	functionId – Type: uint8, Range: See constants
Returns:	responseExpected – Type: bool err – Type: error

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 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:

servo_v2_bricklet.FunctionSetEnable = 2
servo_v2_bricklet.FunctionSetPosition = 4
servo_v2_bricklet.FunctionSetMotionConfiguration = 8
servo_v2_bricklet.FunctionSetPulseWidth = 10
servo_v2_bricklet.FunctionSetDegree = 12
servo_v2_bricklet.FunctionSetPeriod = 14
servo_v2_bricklet.FunctionSetServoCurrentConfiguration = 17
servo_v2_bricklet.FunctionSetInputVoltageConfiguration = 19
servo_v2_bricklet.FunctionSetCurrentCalibration = 23
servo_v2_bricklet.FunctionSetPositionReachedCallbackConfiguration = 25
servo_v2_bricklet.FunctionSetWriteFirmwarePointer = 237
servo_v2_bricklet.FunctionSetStatusLEDConfig = 239
servo_v2_bricklet.FunctionReset = 243
servo_v2_bricklet.FunctionWriteUID = 248

func (*ServoV2Bricklet) SetResponseExpected(functionId uint8, responseExpected bool) (err error)¶

Parameters:	functionId – Type: uint8, Range: See constants responseExpected – Type: bool
Returns:	err – Type: error

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.

The following constants are available for this function:

For functionId:

servo_v2_bricklet.FunctionSetEnable = 2
servo_v2_bricklet.FunctionSetPosition = 4
servo_v2_bricklet.FunctionSetMotionConfiguration = 8
servo_v2_bricklet.FunctionSetPulseWidth = 10
servo_v2_bricklet.FunctionSetDegree = 12
servo_v2_bricklet.FunctionSetPeriod = 14
servo_v2_bricklet.FunctionSetServoCurrentConfiguration = 17
servo_v2_bricklet.FunctionSetInputVoltageConfiguration = 19
servo_v2_bricklet.FunctionSetCurrentCalibration = 23
servo_v2_bricklet.FunctionSetPositionReachedCallbackConfiguration = 25
servo_v2_bricklet.FunctionSetWriteFirmwarePointer = 237
servo_v2_bricklet.FunctionSetStatusLEDConfig = 239
servo_v2_bricklet.FunctionReset = 243
servo_v2_bricklet.FunctionWriteUID = 248

func (*ServoV2Bricklet) SetResponseExpectedAll(responseExpected bool) (err error)¶

Parameters:	responseExpected – Type: bool
Returns:	err – Type: error

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.

func (*ServoV2Bricklet) SetBootloaderMode(mode uint8) (status uint8, err error)¶

Parameters:	mode – Type: uint8, Range: See constants
Returns:	status – Type: uint8, Range: See constants err – Type: error

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:

servo_v2_bricklet.BootloaderModeBootloader = 0
servo_v2_bricklet.BootloaderModeFirmware = 1
servo_v2_bricklet.BootloaderModeBootloaderWaitForReboot = 2
servo_v2_bricklet.BootloaderModeFirmwareWaitForReboot = 3
servo_v2_bricklet.BootloaderModeFirmwareWaitForEraseAndReboot = 4

For status:

servo_v2_bricklet.BootloaderStatusOK = 0
servo_v2_bricklet.BootloaderStatusInvalidMode = 1
servo_v2_bricklet.BootloaderStatusNoChange = 2
servo_v2_bricklet.BootloaderStatusEntryFunctionNotPresent = 3
servo_v2_bricklet.BootloaderStatusDeviceIdentifierIncorrect = 4
servo_v2_bricklet.BootloaderStatusCRCMismatch = 5

func (*ServoV2Bricklet) GetBootloaderMode() (mode uint8, err error)¶

Returns:	mode – Type: uint8, Range: See constants err – Type: error

Returns the current bootloader mode, see SetBootloaderMode().

The following constants are available for this function:

For mode:

servo_v2_bricklet.BootloaderModeBootloader = 0
servo_v2_bricklet.BootloaderModeFirmware = 1
servo_v2_bricklet.BootloaderModeBootloaderWaitForReboot = 2
servo_v2_bricklet.BootloaderModeFirmwareWaitForReboot = 3
servo_v2_bricklet.BootloaderModeFirmwareWaitForEraseAndReboot = 4

func (*ServoV2Bricklet) SetWriteFirmwarePointer(pointer uint32) (err error)¶

Parameters:	pointer – Type: uint32, Unit: 1 B, Range: [0 to 2³² - 1]
Returns:	err – Type: error

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.

func (*ServoV2Bricklet) WriteFirmware(data [64]uint8) (status uint8, err error)¶

Parameters:	data – Type: [64]uint8, Range: [0 to 255]
Returns:	status – Type: uint8, Range: [0 to 255] err – Type: error

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.

func (*ServoV2Bricklet) WriteUID(uid uint32) (err error)¶

Parameters:	uid – Type: uint32, Range: [0 to 2³² - 1]
Returns:	err – Type: error

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.

func (*ServoV2Bricklet) ReadUID() (uid uint32, err error)¶

Returns:	uid – Type: uint32, Range: [0 to 2³² - 1] err – Type: error

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

Constants¶

servo_v2_bricklet.DeviceIdentifier¶

This constant is used to identify a Servo Bricklet 2.0.

The GetIdentity() function and the (*IPConnection) RegisterEnumerateCallback callback of the IPConnection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

servo_v2_bricklet.DeviceDisplayName¶: This constant represents the human readable name of a Servo Bricklet 2.0.