This is the description of the Rust 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 Rust API bindings is part of their general description. Additional documentation can be found on docs.rs.
The example code below is Public Domain (CC0 1.0).
Download (example_configuration.rs)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | use std::{error::Error, io};
use tinkerforge::{ip_connection::IpConnection, servo_v2_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Servo Bricklet 2.0.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let s = ServoV2Bricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // 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).recv()?;
s.set_pulse_width(0, 1000, 2000).recv()?;
s.set_period(0, 19500).recv()?;
s.set_motion_configuration(0, 500000, 1000, 1000).recv()?; // 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).recv()?;
s.set_pulse_width(5, 950, 1950).recv()?;
s.set_period(5, 20000).recv()?;
s.set_motion_configuration(5, 500000, 500000, 500000).recv()?; // Full velocity with full ac-/deceleration
s.set_position(0, 10000).recv()?; // Set to most right position
s.set_enable(0, true).recv()?;
s.set_position(5, -9000).recv()?; // Set to most left position
s.set_enable(5, true).recv()?;
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
s.set_enable(0, false).recv()?;
s.set_enable(5, false).recv()?;
ipcon.disconnect();
Ok(())
}
|
Download (example_callback.rs)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | use std::{error::Error, io, thread};
use tinkerforge::{ip_connection::IpConnection, servo_v2_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Servo Bricklet 2.0.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let s = ServoV2Bricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
let position_reached_receiver = s.get_position_reached_callback_receiver();
// Spawn thread to handle received callback messages.
// This thread ends when the `s` object
// is dropped, so there is no need for manual cleanup.
let s_copy = s.clone(); // Device objects don't implement Sync, so they can't be shared
// between threads (by reference). So clone the device and move the copy.
thread::spawn(move || {
for position_reached in position_reached_receiver {
if position_reached.position == 9000 {
println!("Position: 90°, going to -90°");
s_copy.set_position(position_reached.servo_channel, -9000);
} else if position_reached.position == -9000 {
println!("Position: -90°, going to 90°");
s_copy.set_position(position_reached.servo_channel, 9000);
} else {
// Can only happen if another program sets position
println!("Error");
}
}
});
// Enable position reached callback
s.set_position_reached_callback_configuration(0, true).recv()?;
// 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).recv()?;
s.set_position(0, 9000).recv()?;
s.set_enable(0, true).recv()?;
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
s.set_enable(0, false).recv()?;
ipcon.disconnect();
Ok(())
}
|
To allow non-blocking usage, nearly every function of the Rust bindings returns a wrapper around a mpsc::Receiver. To block until the function has finished and get your result, call one of the receiver's recv variants. Those return either the result sent by the device, or any error occurred.
Functions returning a result directly will block until the device has finished processing the request.
All functions listed below are thread-safe, those which return a receiver are lock-free.
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.
ServoV2Bricklet::
new
(uid: &str, ip_connection: &IpConnection) → ServoV2Bricklet¶Parameters: |
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Returns: |
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Creates a new ServoV2Bricklet
object with the unique device ID uid
and adds
it to the IPConnection ip_connection
:
let servo_v2 = ServoV2Bricklet::new("YOUR_DEVICE_UID", &ip_connection);
This device object can be used after the IP connection has been connected.
ServoV2Bricklet::
get_status
(&self) → ConvertingReceiver<Status>¶Return Object: |
|
---|
Returns the status information of the Servo Bricklet 2.0.
The status includes
Please note that the position and the velocity is a snapshot of the current position and velocity of the servo in motion.
ServoV2Bricklet::
set_enable
(&self, servo_channel: u16, enable: bool) → ConvertingReceiver<()>¶Parameters: |
|
---|
Enables a servo channel (0 to 9). If a servo is enabled, the configured position, velocity, acceleration, etc. are applied immediately.
ServoV2Bricklet::
get_enabled
(&self, servo_channel: u16) → ConvertingReceiver<bool>¶Parameters: |
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---|---|
Returns: |
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Returns true if the specified servo channel is enabled, false otherwise.
ServoV2Bricklet::
set_position
(&self, servo_channel: u16, position: i16) → ConvertingReceiver<()>¶Parameters: |
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Sets the position in °/100 for the specified servo channel.
The default range of the position is -9000 to 9000, but it can be specified
according to your servo with ServoV2Bricklet::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
ServoV2Bricklet::set_degree
.
ServoV2Bricklet::
get_position
(&self, servo_channel: u16) → ConvertingReceiver<i16>¶Parameters: |
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---|---|
Returns: |
|
Returns the position of the specified servo channel as set by ServoV2Bricklet::set_position
.
ServoV2Bricklet::
get_current_position
(&self, servo_channel: u16) → ConvertingReceiver<i16>¶Parameters: |
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Returns: |
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Returns the current position of the specified servo channel. This may not be the
value of ServoV2Bricklet::set_position
if the servo is currently approaching a
position goal.
ServoV2Bricklet::
get_current_velocity
(&self, servo_channel: u16) → ConvertingReceiver<u16>¶Parameters: |
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Returns: |
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Returns the current velocity of the specified servo channel. This may not be the
velocity specified by ServoV2Bricklet::set_motion_configuration
. if the servo is
currently approaching a velocity goal.
ServoV2Bricklet::
set_motion_configuration
(&self, servo_channel: u16, velocity: u32, acceleration: u32, deceleration: u32) → ConvertingReceiver<()>¶Parameters: |
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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).
ServoV2Bricklet::
get_motion_configuration
(&self, servo_channel: u16) → ConvertingReceiver<MotionConfiguration>¶Parameters: |
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Return Object: |
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Returns the motion configuration as set by ServoV2Bricklet::set_motion_configuration
.
ServoV2Bricklet::
set_pulse_width
(&self, servo_channel: u16, min: u32, max: u32) → ConvertingReceiver<()>¶Parameters: |
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Sets the minimum and maximum pulse width of the specified servo channel in µs.
Usually, servos are controlled with a PWM, whereby the length of the pulse controls the position of the servo. Every servo has different minimum and maximum pulse widths, these can be specified with this function.
If you have a datasheet for your servo that specifies the minimum and maximum pulse width, you should set the values accordingly. If your servo comes without any datasheet you have to find the values via trial and error.
Both values have a range from 1 to 65535 (unsigned 16-bit integer). The minimum must be smaller than the maximum.
The default values are 1000µs (1ms) and 2000µs (2ms) for minimum and maximum pulse width.
ServoV2Bricklet::
get_pulse_width
(&self, servo_channel: u16) → ConvertingReceiver<PulseWidth>¶Parameters: |
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Return Object: |
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Returns the minimum and maximum pulse width for the specified servo channel as set by
ServoV2Bricklet::set_pulse_width
.
ServoV2Bricklet::
set_degree
(&self, servo_channel: u16, min: i16, max: i16) → ConvertingReceiver<()>¶Parameters: |
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Sets the minimum and maximum degree for the specified servo channel (by default given as °/100).
This only specifies the abstract values between which the minimum and maximum
pulse width is scaled. For example: If you specify a pulse width of 1000µs
to 2000µs and a degree range of -90° to 90°, a call of ServoV2Bricklet::set_position
with 0 will result in a pulse width of 1500µs
(-90° = 1000µs, 90° = 2000µs, etc.).
Possible usage:
ServoV2Bricklet::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.ServoV2Bricklet::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.
ServoV2Bricklet::
get_degree
(&self, servo_channel: u16) → ConvertingReceiver<Degree>¶Parameters: |
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Return Object: |
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Returns the minimum and maximum degree for the specified servo channel as set by
ServoV2Bricklet::set_degree
.
ServoV2Bricklet::
set_period
(&self, servo_channel: u16, period: u32) → ConvertingReceiver<()>¶Parameters: |
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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).
ServoV2Bricklet::
get_period
(&self, servo_channel: u16) → ConvertingReceiver<u32>¶Parameters: |
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Returns: |
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Returns the period for the specified servo channel as set by ServoV2Bricklet::set_period
.
ServoV2Bricklet::
get_servo_current
(&self, servo_channel: u16) → ConvertingReceiver<u16>¶Parameters: |
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Returns: |
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Returns the current consumption of the specified servo channel in mA.
ServoV2Bricklet::
set_servo_current_configuration
(&self, servo_channel: u16, averaging_duration: u8) → ConvertingReceiver<()>¶Parameters: |
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Sets the averaging duration of the current measurement for the specified servo channel in ms.
ServoV2Bricklet::
get_servo_current_configuration
(&self, servo_channel: u16) → ConvertingReceiver<u8>¶Parameters: |
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Returns: |
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Returns the servo current configuration for the specified servo channel as set
by ServoV2Bricklet::set_servo_current_configuration
.
ServoV2Bricklet::
set_input_voltage_configuration
(&self, averaging_duration: u8) → ConvertingReceiver<()>¶Parameters: |
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Sets the averaging duration of the input voltage measurement for the specified servo channel in ms.
ServoV2Bricklet::
get_input_voltage_configuration
(&self) → ConvertingReceiver<u8>¶Returns: |
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Returns the input voltage configuration as set by ServoV2Bricklet::set_input_voltage_configuration
.
ServoV2Bricklet::
get_overall_current
(&self) → ConvertingReceiver<u16>¶Returns: |
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Returns the current consumption of all servos together in mA.
ServoV2Bricklet::
get_input_voltage
(&self) → ConvertingReceiver<u16>¶Returns: |
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Returns the input voltage in mV. The input voltage is given via the black power input connector on the Servo Brick.
ServoV2Bricklet::
set_current_calibration
(&self, offset: [i16; 10]) → ConvertingReceiver<()>¶Parameters: |
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Sets an offset value (in mA) for each channel.
Note: On delivery the Servo Bricklet 2.0 is already calibrated.
ServoV2Bricklet::
get_current_calibration
(&self) → ConvertingReceiver<[i16; 10]>¶Returns: |
|
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Returns the current calibration as set by ServoV2Bricklet::set_current_calibration
.
ServoV2Bricklet::
get_spitfp_error_count
(&self) → ConvertingReceiver<SpitfpErrorCount>¶Return Object: |
|
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Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.
ServoV2Bricklet::
set_status_led_config
(&self, config: u8) → ConvertingReceiver<()>¶Parameters: |
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Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.
You can also turn the LED permanently on/off or show a heartbeat.
If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.
The following constants are available for this function:
For config:
ServoV2Bricklet::
get_status_led_config
(&self) → ConvertingReceiver<u8>¶Returns: |
|
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Returns the configuration as set by ServoV2Bricklet::set_status_led_config
The following constants are available for this function:
For config:
ServoV2Bricklet::
get_chip_temperature
(&self) → ConvertingReceiver<i16>¶Returns: |
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Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!
The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.
ServoV2Bricklet::
reset
(&self) → ConvertingReceiver<()>¶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!
ServoV2Bricklet::
get_identity
(&self) → ConvertingReceiver<Identity>¶Return Object: |
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---|
Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
ServoV2Bricklet::
set_position_reached_callback_configuration
(&self, servo_channel: u16, enabled: bool) → ConvertingReceiver<()>¶Parameters: |
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Enable/Disable ServoV2Bricklet::get_position_reached_callback_receiver
callback.
ServoV2Bricklet::
get_position_reached_callback_configuration
(&self, servo_channel: u16) → ConvertingReceiver<bool>¶Parameters: |
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Returns: |
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Returns the callback configuration as set by
ServoV2Bricklet::set_position_reached_callback_configuration
.
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding get_*_callback_receiver function, which returns a receiver for callback events.
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.
ServoV2Bricklet::
get_position_reached_callback_receiver
(&self) → ConvertingCallbackReceiver<PositionReachedEvent>¶Event Object: |
|
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Receivers created with this function receive Position Reached events.
This callback is triggered when a position set by ServoV2Bricklet::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 members of the received struct are the servo and the position that is reached.
You can enable this callback with ServoV2Bricklet::set_position_reached_callback_configuration
.
Note
Since we can't get any feedback from the servo, this only works if the
velocity (see ServoV2Bricklet::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 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.
ServoV2Bricklet::
get_api_version
(&self) → [u8; 3]¶Return Object: |
|
---|
Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.
ServoV2Bricklet::
get_response_expected
(&mut self, function_id: u8) → bool¶Parameters: |
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---|---|
Returns: |
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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
ServoV2Bricklet::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:
ServoV2Bricklet::
set_response_expected
(&mut self, function_id: u8, response_expected: bool) → ()¶Parameters: |
|
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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:
ServoV2Bricklet::
set_response_expected_all
(&mut self, response_expected: bool) → ()¶Parameters: |
|
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Changes the response expected flag for all setter and callback configuration functions of this device at once.
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
ServoV2Bricklet::
set_bootloader_mode
(&self, mode: u8) → ConvertingReceiver<u8>¶Parameters: |
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Returns: |
|
Sets the bootloader mode and returns the status after the requested mode change was instigated.
You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
The following constants are available for this function:
For mode:
For status:
ServoV2Bricklet::
get_bootloader_mode
(&self) → ConvertingReceiver<u8>¶Returns: |
|
---|
Returns the current bootloader mode, see ServoV2Bricklet::set_bootloader_mode
.
The following constants are available for this function:
For mode:
ServoV2Bricklet::
set_write_firmware_pointer
(&self, pointer: u32) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the firmware pointer for ServoV2Bricklet::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.
ServoV2Bricklet::
write_firmware
(&self, data: [u8; 64]) → ConvertingReceiver<u8>¶Parameters: |
|
---|---|
Returns: |
|
Writes 64 Bytes of firmware at the position as written by
ServoV2Bricklet::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.
ServoV2Bricklet::
write_uid
(&self, uid: u32) → ConvertingReceiver<()>¶Parameters: |
|
---|
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.
ServoV2Bricklet::
read_uid
(&self) → ConvertingReceiver<u32>¶Returns: |
|
---|
Returns the current UID as an integer. Encode as Base58 to get the usual string version.
ServoV2Bricklet::
DEVICE_IDENTIFIER
¶This constant is used to identify a Servo Bricklet 2.0.
The ServoV2Bricklet::get_identity
function and the IpConnection::get_enumerate_callback_receiver
callback of the IP Connection have a device_identifier
parameter to specify
the Brick's or Bricklet's type.
ServoV2Bricklet::
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Servo Bricklet 2.0.