This is the description of the Rust API bindings for the Load Cell Bricklet 2.0. General information and technical specifications for the Load Cell 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).
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 | use std::{error::Error, io};
use tinkerforge::{ip_connection::IpConnection, load_cell_v2_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Load Cell Bricklet 2.0.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let lc = LoadCellV2Bricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
// Get current weight.
let weight = lc.get_weight().recv()?;
println!("Weight: {} g", weight);
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
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 | use std::{error::Error, io, thread};
use tinkerforge::{ip_connection::IpConnection, load_cell_v2_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Load Cell Bricklet 2.0.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let lc = LoadCellV2Bricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
let weight_receiver = lc.get_weight_callback_receiver();
// Spawn thread to handle received callback messages.
// This thread ends when the `lc` object
// is dropped, so there is no need for manual cleanup.
thread::spawn(move || {
for weight in weight_receiver {
println!("Weight: {} g", weight);
}
});
// Set period for weight callback to 1s (1000ms) without a threshold.
lc.set_weight_callback_configuration(1000, false, 'x', 0, 0);
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
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 | use std::{error::Error, io, thread};
use tinkerforge::{ip_connection::IpConnection, load_cell_v2_bricklet::*};
const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Load Cell Bricklet 2.0.
fn main() -> Result<(), Box<dyn Error>> {
let ipcon = IpConnection::new(); // Create IP connection.
let lc = LoadCellV2Bricklet::new(UID, &ipcon); // Create device object.
ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd.
// Don't use device before ipcon is connected.
let weight_receiver = lc.get_weight_callback_receiver();
// Spawn thread to handle received callback messages.
// This thread ends when the `lc` object
// is dropped, so there is no need for manual cleanup.
thread::spawn(move || {
for weight in weight_receiver {
println!("Weight: {} g", weight);
}
});
// Configure threshold for weight "greater than 200 g"
// with a debounce period of 1s (1000ms).
lc.set_weight_callback_configuration(1000, false, '>', 200, 0);
println!("Press enter to exit.");
let mut _input = String::new();
io::stdin().read_line(&mut _input)?;
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.
LoadCellV2Bricklet::
new
(uid: &str, ip_connection: &IpConnection) → LoadCellV2Bricklet¶Parameters: |
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Returns: |
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Creates a new LoadCellV2Bricklet
object with the unique device ID uid
and adds
it to the IPConnection ip_connection
:
let load_cell_v2 = LoadCellV2Bricklet::new("YOUR_DEVICE_UID", &ip_connection);
This device object can be used after the IP connection has been connected.
LoadCellV2Bricklet::
get_weight
(&self) → ConvertingReceiver<i32>¶Returns: |
|
---|
Returns the currently measured weight.
If you want to get the value periodically, it is recommended to use the
LoadCellV2Bricklet::get_weight_callback_receiver
callback. You can set the callback configuration
with LoadCellV2Bricklet::set_weight_callback_configuration
.
LoadCellV2Bricklet::
set_info_led_config
(&self, config: u8) → ConvertingReceiver<()>¶Parameters: |
|
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Configures the info LED to be either turned off, turned on, or blink in heartbeat mode.
The following constants are available for this function:
For config:
LoadCellV2Bricklet::
get_info_led_config
(&self) → ConvertingReceiver<u8>¶Returns: |
|
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Returns the LED configuration as set by LoadCellV2Bricklet::set_info_led_config
The following constants are available for this function:
For config:
LoadCellV2Bricklet::
tare
(&self) → ConvertingReceiver<()>¶Sets the currently measured weight as tare weight.
LoadCellV2Bricklet::
set_moving_average
(&self, average: u16) → ConvertingReceiver<()>¶Parameters: |
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Sets the length of a moving averaging for the weight value.
Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.
LoadCellV2Bricklet::
get_moving_average
(&self) → ConvertingReceiver<u16>¶Returns: |
|
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Returns the length moving average as set by LoadCellV2Bricklet::set_moving_average
.
LoadCellV2Bricklet::
calibrate
(&self, weight: u32) → ConvertingReceiver<()>¶Parameters: |
|
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To calibrate your Load Cell Bricklet 2.0 you have to
The calibration is saved in the flash of the Bricklet and only needs to be done once.
We recommend to use the Brick Viewer for calibration, you don't need to call this function in your source code.
LoadCellV2Bricklet::
set_configuration
(&self, rate: u8, gain: u8) → ConvertingReceiver<()>¶Parameters: |
|
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The measurement rate and gain are configurable.
The rate can be either 10Hz or 80Hz. A faster rate will produce more noise.
It is additionally possible to add a moving average
(see LoadCellV2Bricklet::set_moving_average
) to the measurements.
The gain can be 128x, 64x or 32x. It represents a measurement range of ±20mV, ±40mV and ±80mV respectively. The Load Cell Bricklet uses an excitation voltage of 5V and most load cells use an output of 2mV/V. That means the voltage range is ±15mV for most load cells (i.e. gain of 128x is best). If you don't know what all of this means you should keep it at 128x, it will most likely be correct.
The following constants are available for this function:
For rate:
For gain:
LoadCellV2Bricklet::
get_configuration
(&self) → ConvertingReceiver<Configuration>¶Return Object: |
|
---|
Returns the configuration as set by LoadCellV2Bricklet::set_configuration
.
The following constants are available for this function:
For rate:
For gain:
LoadCellV2Bricklet::
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.
LoadCellV2Bricklet::
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:
LoadCellV2Bricklet::
get_status_led_config
(&self) → ConvertingReceiver<u8>¶Returns: |
|
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Returns the configuration as set by LoadCellV2Bricklet::set_status_led_config
The following constants are available for this function:
For config:
LoadCellV2Bricklet::
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.
LoadCellV2Bricklet::
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!
LoadCellV2Bricklet::
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.
LoadCellV2Bricklet::
set_weight_callback_configuration
(&self, period: u32, value_has_to_change: bool, option: char, min: i32, max: i32) → ConvertingReceiver<()>¶Parameters: |
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The period is the period with which the LoadCellV2Bricklet::get_weight_callback_receiver
callback is triggered
periodically. A value of 0 turns the callback off.
If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.
If it is set to false, the callback is continuously triggered with the period, independent of the value.
It is furthermore possible to constrain the callback with thresholds.
The option-parameter together with min/max sets a threshold for the LoadCellV2Bricklet::get_weight_callback_receiver
callback.
The following options are possible:
Option | Description |
---|---|
'x' | Threshold is turned off |
'o' | Threshold is triggered when the value is outside the min and max values |
'i' | Threshold is triggered when the value is inside or equal to the min and max values |
'<' | Threshold is triggered when the value is smaller than the min value (max is ignored) |
'>' | Threshold is triggered when the value is greater than the min value (max is ignored) |
If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.
The following constants are available for this function:
For option:
LoadCellV2Bricklet::
get_weight_callback_configuration
(&self) → ConvertingReceiver<WeightCallbackConfiguration>¶Return Object: |
|
---|
Returns the callback configuration as set by LoadCellV2Bricklet::set_weight_callback_configuration
.
The following constants are available for this function:
For option:
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.
LoadCellV2Bricklet::
get_weight_callback_receiver
(&self) → ConvertingCallbackReceiver<i32>¶Event: |
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Receivers created with this function receive Weight events.
This callback is triggered periodically according to the configuration set by
LoadCellV2Bricklet::set_weight_callback_configuration
.
The received variable is the same as LoadCellV2Bricklet::get_weight
.
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.
LoadCellV2Bricklet::
get_api_version
(&self) → [u8; 3]¶Return Object: |
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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.
LoadCellV2Bricklet::
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
LoadCellV2Bricklet::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:
LoadCellV2Bricklet::
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:
LoadCellV2Bricklet::
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.
LoadCellV2Bricklet::
set_bootloader_mode
(&self, mode: u8) → ConvertingReceiver<u8>¶Parameters: |
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Returns: |
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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:
LoadCellV2Bricklet::
get_bootloader_mode
(&self) → ConvertingReceiver<u8>¶Returns: |
|
---|
Returns the current bootloader mode, see LoadCellV2Bricklet::set_bootloader_mode
.
The following constants are available for this function:
For mode:
LoadCellV2Bricklet::
set_write_firmware_pointer
(&self, pointer: u32) → ConvertingReceiver<()>¶Parameters: |
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Sets the firmware pointer for LoadCellV2Bricklet::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.
LoadCellV2Bricklet::
write_firmware
(&self, data: [u8; 64]) → ConvertingReceiver<u8>¶Parameters: |
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Returns: |
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Writes 64 Bytes of firmware at the position as written by
LoadCellV2Bricklet::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.
LoadCellV2Bricklet::
write_uid
(&self, uid: u32) → ConvertingReceiver<()>¶Parameters: |
|
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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.
LoadCellV2Bricklet::
read_uid
(&self) → ConvertingReceiver<u32>¶Returns: |
|
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Returns the current UID as an integer. Encode as Base58 to get the usual string version.
LoadCellV2Bricklet::
DEVICE_IDENTIFIER
¶This constant is used to identify a Load Cell Bricklet 2.0.
The LoadCellV2Bricklet::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.
LoadCellV2Bricklet::
DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a Load Cell Bricklet 2.0.