scale

Functions

get_scale(address)

Factory function to initialize the Scale.

real_weight_inference(weight_array, threshold)

Determines if a sequence of weight measurements represents a stable weight.

Classes

Scale(address)

Interface for an I2C scale sensor.
class Scale(address: str)[source]

Bases: ScaleBase

Interface for an I2C scale sensor.

I2C_ADDR

The I2C address of the scale.

Type:

int

REG_DATA_GET_RAM_DATA

Register address for getting raw data.

Type:

int

bus

The I2C bus number.

Type:

int

calibration

Calibration factor.

Type:

float

offset

Tare offset.

Type:

float

i2cbus

The I2C bus connection.

Type:

smbus2.SMBus

error

Error message if any.

Type:

str

error_message_timer

Timer to limit error logging frequency.

Type:

time_utils.Timer

alarm_timer

Timer for non-responsive alarms.

Type:

time_utils.Timer

tare() → None[source]

Tares the scale (sets the current weight as zero).

calibrate(weight: float) → None[source]

Calibrates the scale with a known weight.

Parameters:

weight (float) – The known weight in grams used for calibration.

get_value(samples: int = 1, interval_s: float = 0.005) → int[source]

Reads raw values from the scale.

Parameters:

  • samples (int) – Number of samples to read.

  • interval_s (float) – Delay between samples in seconds.

Returns:

The median of the raw values.

Return type:

int

get_weight() → float[source]

Gets the current weight in grams.

Returns:

The weight in grams.

Return type:

float

get_scale(address: str) → ScaleBase[source]

Factory function to initialize the Scale.

Parameters:

address (str) – The I2C address of the scale.

Returns:

An initialized Scale instance or a base class on failure.

Return type:

ScaleBase

real_weight_inference(weight_array, threshold) → tuple[bool, float][source]

Determines if a sequence of weight measurements represents a stable weight.

Conditions to call it a real weight:
  • standard deviation of the last 5 measurements is

    smaller than 10% of the threshold

Parameters:

  • weight_array (list | np.ndarray) – Array of weight measurements.

  • threshold (float) – Threshold for stability check.

Returns:

(True, median_weight) if stable, else (False, 0.0).

Return type:

tuple[bool, float]