This is the description of the Rust API bindings for the Laser Range Finder Bricklet. General information and technical specifications for the Laser Range Finder Bricklet 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).
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 | use std::{error::Error, io, thread, time::Duration};
use tinkerforge::{ip_connection::IpConnection, laser_range_finder_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Laser Range Finder Bricklet.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let lrf = LaserRangeFinderBricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
// Turn laser on and wait 250ms for very first measurement to be ready
lrf.enable_laser().recv()?;
thread::sleep(Duration::from_millis(250));
// Get current distance.
let distance = lrf.get_distance().recv()?;
println!("Distance: {} cm", distance);
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
lrf.disable_laser().recv()?; // Turn laser off
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 | use std::{error::Error, io, thread, time::Duration};
use tinkerforge::{ip_connection::IpConnection, laser_range_finder_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Laser Range Finder Bricklet.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let lrf = LaserRangeFinderBricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
// Turn laser on and wait 250ms for very first measurement to be ready
lrf.enable_laser().recv()?;
thread::sleep(Duration::from_millis(250));
let distance_receiver = lrf.get_distance_callback_receiver();
// Spawn thread to handle received callback messages.
// This thread ends when the `lrf` object
// is dropped, so there is no need for manual cleanup.
thread::spawn(move || {
for distance in distance_receiver {
println!("Distance: {} cm", distance);
}
});
// Set period for distance receiver to 0.2s (200ms).
// Note: The distance callback is only called every 0.2 seconds
// if the distance has changed since the last call!
lrf.set_distance_callback_period(200);
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
lrf.disable_laser().recv()?; // Turn laser off
ipcon.disconnect();
Ok(())
}
|
Download (example_threshold.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 | use std::{error::Error, io, thread, time::Duration};
use tinkerforge::{ip_connection::IpConnection, laser_range_finder_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Laser Range Finder Bricklet.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let lrf = LaserRangeFinderBricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
// Turn laser on and wait 250ms for very first measurement to be ready
lrf.enable_laser().recv()?;
thread::sleep(Duration::from_millis(250));
// Get threshold receivers with a debounce time of 10 seconds (10000ms).
lrf.set_debounce_period(10000);
let distance_reached_receiver = lrf.get_distance_reached_callback_receiver();
// Spawn thread to handle received callback messages.
// This thread ends when the `lrf` object
// is dropped, so there is no need for manual cleanup.
thread::spawn(move || {
for distance_reached in distance_reached_receiver {
println!("Distance: {} cm", distance_reached);
}
});
// Configure threshold for distance "greater than 20 cm".
lrf.set_distance_callback_threshold('>', 20, 0);
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
lrf.disable_laser().recv()?; // Turn laser off
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.
LaserRangeFinderBricklet::
new
(uid: &str, ip_connection: &IpConnection) → LaserRangeFinderBricklet¶Parameters: |
|
---|---|
Returns: |
|
Creates a new LaserRangeFinderBricklet
object with the unique device ID uid
and adds
it to the IPConnection ip_connection
:
let laser_range_finder = LaserRangeFinderBricklet::new("YOUR_DEVICE_UID", &ip_connection);
This device object can be used after the IP connection has been connected.
LaserRangeFinderBricklet::
get_distance
(&self) → ConvertingReceiver<u16>¶Returns: |
|
---|
Returns the measured distance.
Sensor hardware version 1 (see LaserRangeFinderBricklet::get_sensor_hardware_version
) cannot
measure distance and velocity at the same time. Therefore, the distance mode
has to be enabled using LaserRangeFinderBricklet::set_mode
.
Sensor hardware version 3 can measure distance and velocity at the same
time. Also the laser has to be enabled, see LaserRangeFinderBricklet::enable_laser
.
If you want to get the distance periodically, it is recommended to
use the LaserRangeFinderBricklet::get_distance_callback_receiver
callback and set the period with
LaserRangeFinderBricklet::set_distance_callback_period
.
LaserRangeFinderBricklet::
get_velocity
(&self) → ConvertingReceiver<i16>¶Returns: |
|
---|
Returns the measured velocity.
Sensor hardware version 1 (see LaserRangeFinderBricklet::get_sensor_hardware_version
) cannot
measure distance and velocity at the same time. Therefore, the velocity mode
has to be enabled using LaserRangeFinderBricklet::set_mode
.
Sensor hardware version 3 can measure distance and velocity at the same
time, but the velocity measurement only produces stables results if a fixed
measurement rate (see LaserRangeFinderBricklet::set_configuration
) is configured. Also the laser
has to be enabled, see LaserRangeFinderBricklet::enable_laser
.
If you want to get the velocity periodically, it is recommended to
use the LaserRangeFinderBricklet::get_velocity_callback_receiver
callback and set the period with
LaserRangeFinderBricklet::set_velocity_callback_period
.
LaserRangeFinderBricklet::
set_mode
(&self, mode: u8) → ConvertingReceiver<()>¶Parameters: |
|
---|
Note
This function is only available if you have a LIDAR-Lite sensor with hardware
version 1. Use LaserRangeFinderBricklet::set_configuration
for hardware version 3. You can check
the sensor hardware version using LaserRangeFinderBricklet::get_sensor_hardware_version
.
The LIDAR-Lite sensor (hardware version 1) has five different modes. One mode is for distance measurements and four modes are for velocity measurements with different ranges.
The following modes are available:
The following constants are available for this function:
For mode:
LaserRangeFinderBricklet::
get_mode
(&self) → ConvertingReceiver<u8>¶Returns: |
|
---|
Returns the mode as set by LaserRangeFinderBricklet::set_mode
.
The following constants are available for this function:
For mode:
LaserRangeFinderBricklet::
enable_laser
(&self) → ConvertingReceiver<()>¶Activates the laser of the LIDAR.
We recommend that you wait 250ms after enabling the laser before
the first call of LaserRangeFinderBricklet::get_distance
to ensure stable measurements.
LaserRangeFinderBricklet::
disable_laser
(&self) → ConvertingReceiver<()>¶Deactivates the laser of the LIDAR.
LaserRangeFinderBricklet::
is_laser_enabled
(&self) → ConvertingReceiver<bool>¶Returns: |
|
---|
Returns true if the laser is enabled, false otherwise.
LaserRangeFinderBricklet::
set_configuration
(&self, acquisition_count: u8, enable_quick_termination: bool, threshold_value: u8, measurement_frequency: u16) → ConvertingReceiver<()>¶Parameters: |
|
---|
Note
This function is only available if you have a LIDAR-Lite sensor with hardware
version 3. Use LaserRangeFinderBricklet::set_mode
for hardware version 1. You can check
the sensor hardware version using LaserRangeFinderBricklet::get_sensor_hardware_version
.
The Acquisition Count defines the number of times the Laser Range Finder Bricklet will integrate acquisitions to find a correlation record peak. With a higher count, the Bricklet can measure longer distances. With a lower count, the rate increases. The allowed values are 1-255.
If you set Enable Quick Termination to true, the distance measurement will be terminated early if a high peak was already detected. This means that a higher measurement rate can be achieved and long distances can be measured at the same time. However, the chance of false-positive distance measurements increases.
Normally the distance is calculated with a detection algorithm that uses peak value, signal strength and noise. You can however also define a fixed Threshold Value. Set this to a low value if you want to measure the distance to something that has very little reflection (e.g. glass) and set it to a high value if you want to measure the distance to something with a very high reflection (e.g. mirror). Set this to 0 to use the default algorithm. The other allowed values are 1-255.
Set the Measurement Frequency to force a fixed measurement rate. If set to 0, the Laser Range Finder Bricklet will use the optimal frequency according to the other configurations and the actual measured distance. Since the rate is not fixed in this case, the velocity measurement is not stable. For a stable velocity measurement you should set a fixed measurement frequency. The lower the frequency, the higher is the resolution of the calculated velocity. The allowed values are 10Hz-500Hz (and 0 to turn the fixed frequency off).
New in version 2.0.3 (Plugin).
LaserRangeFinderBricklet::
get_configuration
(&self) → ConvertingReceiver<Configuration>¶Return Object: |
|
---|
Returns the configuration as set by LaserRangeFinderBricklet::set_configuration
.
New in version 2.0.3 (Plugin).
LaserRangeFinderBricklet::
set_moving_average
(&self, distance_average_length: u8, velocity_average_length: u8) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the length of a moving averaging for the distance and velocity.
Setting the length to 0 will turn the averaging completely off. With less averaging, there is more noise on the data.
LaserRangeFinderBricklet::
get_moving_average
(&self) → ConvertingReceiver<MovingAverage>¶Return Object: |
|
---|
Returns the length moving average as set by LaserRangeFinderBricklet::set_moving_average
.
LaserRangeFinderBricklet::
get_sensor_hardware_version
(&self) → ConvertingReceiver<u8>¶Returns: |
|
---|
Returns the LIDAR-Lite hardware version.
The following constants are available for this function:
For version:
New in version 2.0.3 (Plugin).
LaserRangeFinderBricklet::
get_identity
(&self) → ConvertingReceiver<Identity>¶Return Object: |
|
---|
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.
LaserRangeFinderBricklet::
set_distance_callback_period
(&self, period: u32) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the period with which the LaserRangeFinderBricklet::get_distance_callback_receiver
callback is triggered
periodically. A value of 0 turns the callback off.
The LaserRangeFinderBricklet::get_distance_callback_receiver
callback is only triggered if the distance value has
changed since the last triggering.
LaserRangeFinderBricklet::
get_distance_callback_period
(&self) → ConvertingReceiver<u32>¶Returns: |
|
---|
Returns the period as set by LaserRangeFinderBricklet::set_distance_callback_period
.
LaserRangeFinderBricklet::
set_velocity_callback_period
(&self, period: u32) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the period with which the LaserRangeFinderBricklet::get_velocity_callback_receiver
callback is triggered
periodically. A value of 0 turns the callback off.
The LaserRangeFinderBricklet::get_velocity_callback_receiver
callback is only triggered if the velocity value has
changed since the last triggering.
LaserRangeFinderBricklet::
get_velocity_callback_period
(&self) → ConvertingReceiver<u32>¶Returns: |
|
---|
Returns the period as set by LaserRangeFinderBricklet::set_velocity_callback_period
.
LaserRangeFinderBricklet::
set_distance_callback_threshold
(&self, option: char, min: u16, max: u16) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the thresholds for the LaserRangeFinderBricklet::get_distance_reached_callback_receiver
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the distance value is outside the min and max values |
'i' | Callback is triggered when the distance value is inside the min and max values |
'<' | Callback is triggered when the distance value is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the distance value is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
LaserRangeFinderBricklet::
get_distance_callback_threshold
(&self) → ConvertingReceiver<DistanceCallbackThreshold>¶Return Object: |
|
---|
Returns the threshold as set by LaserRangeFinderBricklet::set_distance_callback_threshold
.
The following constants are available for this function:
For option:
LaserRangeFinderBricklet::
set_velocity_callback_threshold
(&self, option: char, min: i16, max: i16) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the thresholds for the LaserRangeFinderBricklet::get_velocity_reached_callback_receiver
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the velocity is outside the min and max values |
'i' | Callback is triggered when the velocity is inside the min and max values |
'<' | Callback is triggered when the velocity is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the velocity is greater than the min value (max is ignored) |
The following constants are available for this function:
For option:
LaserRangeFinderBricklet::
get_velocity_callback_threshold
(&self) → ConvertingReceiver<VelocityCallbackThreshold>¶Return Object: |
|
---|
Returns the threshold as set by LaserRangeFinderBricklet::set_velocity_callback_threshold
.
The following constants are available for this function:
For option:
LaserRangeFinderBricklet::
set_debounce_period
(&self, debounce: u32) → ConvertingReceiver<()>¶Parameters: |
|
---|
Sets the period with which the threshold callbacks
LaserRangeFinderBricklet::get_distance_reached_callback_receiver
,LaserRangeFinderBricklet::get_velocity_reached_callback_receiver
,are triggered, if the thresholds
LaserRangeFinderBricklet::set_distance_callback_threshold
,LaserRangeFinderBricklet::set_velocity_callback_threshold
,keep being reached.
LaserRangeFinderBricklet::
get_debounce_period
(&self) → ConvertingReceiver<u32>¶Returns: |
|
---|
Returns the debounce period as set by LaserRangeFinderBricklet::set_debounce_period
.
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.
LaserRangeFinderBricklet::
get_distance_callback_receiver
(&self) → ConvertingCallbackReceiver<u16>¶Event: |
|
---|
Receivers created with this function receive Distance events.
This callback is triggered periodically with the period that is set by
LaserRangeFinderBricklet::set_distance_callback_period
. The received variable is the distance
value of the sensor.
The LaserRangeFinderBricklet::get_distance_callback_receiver
callback is only triggered if the distance value has changed
since the last triggering.
LaserRangeFinderBricklet::
get_velocity_callback_receiver
(&self) → ConvertingCallbackReceiver<i16>¶Event: |
|
---|
Receivers created with this function receive Velocity events.
This callback is triggered periodically with the period that is set by
LaserRangeFinderBricklet::set_velocity_callback_period
. The received variable is the velocity
value of the sensor.
The LaserRangeFinderBricklet::get_velocity_callback_receiver
callback is only triggered if the velocity has changed since
the last triggering.
LaserRangeFinderBricklet::
get_distance_reached_callback_receiver
(&self) → ConvertingCallbackReceiver<u16>¶Event: |
|
---|
Receivers created with this function receive Distance Reached events.
This callback is triggered when the threshold as set by
LaserRangeFinderBricklet::set_distance_callback_threshold
is reached.
The received variable is the distance value of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by LaserRangeFinderBricklet::set_debounce_period
.
LaserRangeFinderBricklet::
get_velocity_reached_callback_receiver
(&self) → ConvertingCallbackReceiver<i16>¶Event: |
|
---|
Receivers created with this function receive Velocity Reached events.
This callback is triggered when the threshold as set by
LaserRangeFinderBricklet::set_velocity_callback_threshold
is reached.
The received variable is the velocity value of the sensor.
If the threshold keeps being reached, the callback is triggered periodically
with the period as set by LaserRangeFinderBricklet::set_debounce_period
.
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.
LaserRangeFinderBricklet::
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.
LaserRangeFinderBricklet::
get_response_expected
(&mut self, function_id: u8) → bool¶Parameters: |
|
---|---|
Returns: |
|
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
LaserRangeFinderBricklet::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:
LaserRangeFinderBricklet::
set_response_expected
(&mut self, function_id: u8, response_expected: bool) → ()¶Parameters: |
|
---|
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:
LaserRangeFinderBricklet::
set_response_expected_all
(&mut self, response_expected: bool) → ()¶Parameters: |
|
---|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
LaserRangeFinderBricklet::
DEVICE_IDENTIFIER
¶This constant is used to identify a Laser Range Finder Bricklet.
The LaserRangeFinderBricklet::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.
LaserRangeFinderBricklet::
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Laser Range Finder Bricklet.