Struct LoadCellBricklet

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pub struct LoadCellBricklet { /* private fields */ }

Expand description

Measures weight with a load cell

Implementations§

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pub fn new(uid: Uid, connection: AsyncIpConnection) -> LoadCellBricklet

Creates an object with the unique device ID uid. This object can then be used after the IP Connection ip_connection is connected.

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pub fn get_response_expected( &mut self, fun: LoadCellBrickletFunction, ) -> Result<bool, GetResponseExpectedError>

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 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.

See set_response_expected for the list of function ID constants available for this function.

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pub fn set_response_expected( &mut self, fun: LoadCellBrickletFunction, response_expected: bool, ) -> Result<(), SetResponseExpectedError>

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.

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pub fn set_response_expected_all(&mut self, response_expected: bool)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

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pub fn get_api_version(&self) -> [u8; 3]

Returns the version of the API definition (major, minor, revision) 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.

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pub async fn get_weight_callback_receiver(&mut self) -> impl Stream<Item = i32>

This receiver is triggered periodically with the period that is set by set_weight_callback_period. The parameter is the weight as measured by the load cell.

The get_weight_callback_receiver receiver is only triggered if the weight has changed since the last triggering.

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pub async fn get_weight_reached_callback_receiver( &mut self, ) -> impl Stream<Item = i32>

This receiver is triggered when the threshold as set by [set_weight_callback_threshold] is reached. The parameter is the weight as measured by the load cell.

If the threshold keeps being reached, the receiver is triggered periodically with the period as set by [set_debounce_period].

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pub async fn get_weight(&mut self) -> Result<i32, TinkerforgeError>

Returns the currently measured weight.

If you want to get the weight periodically, it is recommended to use the [get_weight_callback_receiver] receiver and set the period with [set_weight_callback_period].

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pub async fn set_weight_callback_period( &mut self, period: u32, ) -> Result<(), TinkerforgeError>

Sets the period with which the [get_weight_callback_receiver] receiver is triggered periodically. A value of 0 turns the receiver off.

The [get_weight_callback_receiver] receiver is only triggered if the weight has changed since the last triggering.

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pub async fn get_weight_callback_period( &mut self, ) -> Result<u32, TinkerforgeError>

Returns the period as set by [set_weight_callback_period].

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pub async fn set_weight_callback_threshold( &mut self, option: char, min: i32, max: i32, ) -> Result<(), TinkerforgeError>

Sets the thresholds for the [get_weight_reached_callback_receiver] receiver.

The following options are possible:

Option	Description
‘x’	Receiver is turned off
‘o’	Receiver is triggered when the weight is outside the min and max values
‘i’	Receiver is triggered when the weight is inside the min and max values
‘<’	Receiver is triggered when the weight is smaller than the min value (max is ignored)
‘>’	Receiver is triggered when the weight is greater than the min value (max is ignored)

Associated constants:

LOAD_CELL_BRICKLET_THRESHOLD_OPTION_OFF
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_OUTSIDE
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_INSIDE
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_SMALLER
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_GREATER

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pub async fn get_weight_callback_threshold( &mut self, ) -> Result<WeightCallbackThreshold, TinkerforgeError>

Returns the threshold as set by [set_weight_callback_threshold].

Associated constants:

LOAD_CELL_BRICKLET_THRESHOLD_OPTION_OFF
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_OUTSIDE
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_INSIDE
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_SMALLER
LOAD_CELL_BRICKLET_THRESHOLD_OPTION_GREATER

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pub async fn set_debounce_period( &mut self, debounce: u32, ) -> Result<(), TinkerforgeError>

Sets the period with which the threshold receiver

[get_weight_reached_callback_receiver]

is triggered, if the threshold

[set_weight_callback_threshold]

keeps being reached.

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pub async fn get_debounce_period(&mut self) -> Result<u32, TinkerforgeError>

Returns the debounce period as set by [set_debounce_period].

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pub async fn set_moving_average( &mut self, average: u8, ) -> Result<(), TinkerforgeError>

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.

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pub async fn get_moving_average(&mut self) -> Result<u8, TinkerforgeError>

Returns the length moving average as set by [set_moving_average].

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pub async fn led_on(&mut self) -> Result<(), TinkerforgeError>

Turns the LED on.

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pub async fn led_off(&mut self) -> Result<(), TinkerforgeError>

Turns the LED off.

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pub async fn is_led_on(&mut self) -> Result<bool, TinkerforgeError>

Returns true if the led is on, false otherwise.

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pub async fn calibrate(&mut self, weight: u32) -> Result<(), TinkerforgeError>

To calibrate your Load Cell Bricklet you have to

empty the scale and call this function with 0 and
add a known weight to the scale and call this function with the weight.

The calibration is saved in the EEPROM 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.

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pub async fn tare(&mut self) -> Result<(), TinkerforgeError>

Sets the currently measured weight as tare weight.

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pub async fn set_configuration( &mut self, rate: u8, gain: u8, ) -> Result<(), TinkerforgeError>

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 [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 configuration is saved in the EEPROM of the Bricklet and only needs to be done once.

We recommend to use the Brick Viewer for configuration, you don’t need to call this function in your source code.

Associated constants: