def set_units(self,
distance_units=None,
speed_units=None,
acceleration_units=None):
"""
Sets the units this instance will use.
These units are used in with settings and the data returned.
By default SI units (m and m/s) are used. It is a good idea to set the units before any other commands are sent
if using non-default units.
:param distance_units: The distance units to use: "mm", "cm", "m", "km", "in", "ft", "mi"
:type distance_units: str
:param speed_units: The speed units to use: "mm/s", "cm/s", "m/s", "km/h", "in/s", "ft/s", "mi/h"
:type speed_units: str
:param acceleration_units: The acceleration units to use: "mm/s^2", "m/s^2", "in/s^2", "ft/s^2"
:type acceleration_units: str
"""
try:
# Performing a units conversion will throw an exception if the units are not valid
if distance_units is not None:
units.convert_distance_to_si(distance_units, 1)
self.distance_units = distance_units
if speed_units is not None:
units.convert_speed_to_si(speed_units, 1)
self.speed_units = speed_units
if acceleration_units is not None:
units.convert_acceleration_to_si(acceleration_units, 1)
self.acceleration_units = acceleration_units
except ValueError as err:
raise ValueError(err)
def set_distance_filter(self, minimum, maximum):
"""
Sets the distance filter applied to the readings.
:param minimum: The minimum distance (in units as specified by :meth:`set_units`)
:type minimum: number
:param maximum: The maximum distance (in units as specified by :meth:`set_units`)
:type maximum: number
"""
minimum = int(
units.convert_distance_to_si(self.distance_units, minimum) * 1000)
maximum = int(
units.convert_distance_to_si(self.distance_units, maximum) * 1000)
if not (isinstance(minimum, int) and 0 <= minimum <= 10000):
raise ValueError(
"Distance filter minimum must be a number between 0 and 10000mm"
)
if not (isinstance(maximum, int) and 0 <= maximum <= 10000):
raise ValueError(
"Distance filter maximum must be a number between 0 and 10000mm"
)
if maximum < minimum:
raise ValueError(
"Distance filter maximum must be greater than the minimum")
try:
self._send(pack("<BBHH", 0x06, 0x02, minimum, maximum))
res = unpack("<BBHH", self._read())
if res[0] == 0x06 and res[1] == 0x01:
if res[2] == minimum and res[3] == maximum:
return True
else:
raise Exception("Distance filter did not set correctly")
else:
raise Exception("Invalid response")
except Exception:
raise Exception("Failed to set distance filter")
def test_convert_from_mi_to_m(self):
# Test conversions of distances to SI units
converted = units.convert_distance_to_si('mi', 0.135)
self.assertEqual(217.3, converted)
def test_convert_from_ft_to_m(self):
# Test conversions of distances to SI units
converted = units.convert_distance_to_si('ft', 23)
self.assertEqual(7.01, converted)
def test_convert_from_km_to_m(self):
# Test conversions of distances to SI units
converted = units.convert_distance_to_si('km', 0.123)
self.assertEqual(123, converted)
def test_convert_from_mm_to_m(self):
# Test conversions of distances to SI units
converted = units.convert_distance_to_si('mm', 1010)
self.assertEqual(1.01, converted)
def test_convert_from_m_to_m(self):
# Test the identity conversion
converted = units.convert_distance_to_si('m', 1.01)
self.assertEqual(1.01, converted)