Distance Sensor

Distance Sensor — is an active sensor that measures the distance to an object with high precision. The sensor uses an infrared laser and records the time it takes for the laser to return back.

Basic usage

DistanceSensor(slot)

To create DistanceSensor object call DistanceSensor(slot).

Also you can use short alias Distance(slot).

You can choose any other slot (except "C", as it does not support I2C communication).

Args:

  • slot (string | int | tuple) - slot label ("A", "B", "D", "E", "F", "G", "H"), pin port (0, 2 and etc.), tuple (0, Pin.OUT)

Returns: Return a class VL53L0X for slot.

from pibody import DistanceSensor

distance = DistanceSensor("A")

.read() -> int

Perform a single ranging measurement.
Returns distance in mm [20, 2000].
Returns 20 or 8190 if invalid measurement.

from pibody import Distance   # short alias
distance = Distance('A')

data = distance.read()

print(data)

.is_valid(distance) -> bool

Parameter distance is mandatory which should contained actual distance in mm.

Returns True or False if measurements between .min_valid_mm and .max_valid_mm are valid.
min_valid_mm by default is 30.
max_valid_mm by default is 2000.
These variables can be changed.

from pibody import Distance   # short alias
distance = Distance('A')

distance.min_valid_mm = 50
distance.max_valid_mm = 200

curr_dist = distance.read()

valid = distance.is_valid(curr_dist)
print(valid)

Other Functions

.bar() -> string

Return a text progress-bar of the current distance.

Args:

  • max_range (int | None) - distance (mm) that corresponds to a full bar. By default is 200 mm
  • width (int | None) - bar width in characters. By default is 20 symbols
  • fill_char (string | None) - character used for the filled portion. By default is “#”
  • empty_char (string | None) - character used for the empty portion. By default is " "
from pibody import Distance   # short alias
distance = Distance('A')

bar = distance.bar()

print(bar) # [######  ] 75 mm

.add_close_trigger(threshold_mm, callback)

Register a callback fired when an object is closer than threshold_mm.

Args:

  • threshold_mm (int) - distance threshold in mm
  • callback - called with the current distance (mm)
distance.add_close_trigger(100, cb)

.add_motion_trigger(change_threshold_mm, callback, cooldown_ms)

Register a callback fired when the distance changes by more than change_threshold_mm between consecutive check() calls.

Args:

  • change_threshold_mm (int) - minimum delta (mm) to trigger
  • callback - called with (distance_mm, delta_mm)
  • cooldown_ms - minimum ms between consecutive triggers. By default is 500
distance.add_motion_trigger(100, cb)

.check()

Read distance and fire any registered callbacks.

Should be called periodically from the main loop. Invalid readings are silently ignored.

distance.add_motion_trigger(100, cb)

while True:
    distance.check()