Source code for adafruit_vcnl4010

# SPDX-FileCopyrightText: 2017 Tony DiCola for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
`adafruit_vcnl4010`
====================================================

CircuitPython module for the VCNL4010 proximity and light sensor.  See
examples/vcnl4010_simpletest.py for an example of the usage.

* Author(s): Tony DiCola

Implementation Notes
--------------------

**Hardware:**

* Adafruit `VCNL4010 Proximity/Light sensor breakout
  <https://www.adafruit.com/product/466>`_ (Product ID: 466)

**Software and Dependencies:**

* Adafruit CircuitPython firmware for the supported boards:
  https://circuitpython.org/downloads

* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
"""
from micropython import const

import adafruit_bus_device.i2c_device as i2c_device


__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_VCNL4010.git"


# Internal constants:
_VCNL4010_I2CADDR_DEFAULT = const(0x13)
_VCNL4010_COMMAND = const(0x80)
_VCNL4010_PRODUCTID = const(0x81)
_VCNL4010_PROXRATE = const(0x82)
_VCNL4010_IRLED = const(0x83)
_VCNL4010_AMBIENTPARAMETER = const(0x84)
_VCNL4010_AMBIENTDATA = const(0x85)
_VCNL4010_PROXIMITYDATA = const(0x87)
_VCNL4010_INTCONTROL = const(0x89)
_VCNL4010_PROXIMITYADJUST = const(0x8A)
_VCNL4010_INTSTAT = const(0x8E)
_VCNL4010_MODTIMING = const(0x8F)
_VCNL4010_MEASUREAMBIENT = const(0x10)
_VCNL4010_MEASUREPROXIMITY = const(0x08)
_VCNL4010_AMBIENTREADY = const(0x40)
_VCNL4010_PROXIMITYREADY = const(0x20)
_VCNL4010_AMBIENT_LUX_SCALE = 0.25  # Lux value per 16-bit result value.

# User-facing constants:
FREQUENCY_3M125 = 3
FREQUENCY_1M5625 = 2
FREQUENCY_781K25 = 1
FREQUENCY_390K625 = 0

# Disable pylint's name warning as it causes too much noise.  Suffixes like
# BE (big-endian) or mA (milli-amps) don't confirm to its conventions--by
# design (clarity of code and explicit units).  Disable this globally to prevent
# littering the code with pylint disable and enable and making it less readable.
# pylint: disable=invalid-name


[docs]class VCNL4010: """Vishay VCNL4010 proximity and ambient light sensor. :param ~busio.I2C i2c: The I2C bus the VCNL4010 is connected to :param int address: (optional) The I2C address of the device. Defaults to :const:`0x13` **Quickstart: Importing and using the VCNL4010** Here is an example of using the :class:`VCNL4010` class. First you will need to import the libraries to use the sensor .. code-block:: python import board import adafruit_vcnl4010 Once this is done you can define your `board.I2C` object and define your sensor object .. code-block:: python i2c = board.I2C() # uses board.SCL and board.SDA sensor = adafruit_vcnl4010.VCNL4010(i2c) Now you have access to the :attr:`sensor.proximity` and :attr:`ambient_lux` attributes .. code-block:: python proximity = sensor.proximity ambient_lux = sensor.ambient_lux """ # Class-level buffer for reading and writing data with the sensor. # This reduces memory allocations but means the code is not re-entrant or # thread safe! _BUFFER = bytearray(3) def __init__(self, i2c, address=_VCNL4010_I2CADDR_DEFAULT): self._device = i2c_device.I2CDevice(i2c, address) # Verify chip ID. revision = self._read_u8(_VCNL4010_PRODUCTID) if (revision & 0xF0) != 0x20: raise RuntimeError("Failed to find VCNL4010, check wiring!") self.led_current = 20 self.frequency = FREQUENCY_390K625 self._write_u8(_VCNL4010_INTCONTROL, 0x08) def _read_u8(self, address): # Read an 8-bit unsigned value from the specified 8-bit address. with self._device as i2c: self._BUFFER[0] = address & 0xFF i2c.write_then_readinto(self._BUFFER, self._BUFFER, out_end=1, in_start=1) return self._BUFFER[1] def _read_u16BE(self, address): # Read a 16-bit big-endian unsigned value from the specified 8-bit address. with self._device as i2c: self._BUFFER[0] = address & 0xFF i2c.write_then_readinto(self._BUFFER, self._BUFFER, out_end=1, in_start=1) return (self._BUFFER[1] << 8) | self._BUFFER[2] def _write_u8(self, address, val): # Write an 8-bit unsigned value to the specified 8-bit address. with self._device as i2c: self._BUFFER[0] = address & 0xFF self._BUFFER[1] = val & 0xFF i2c.write(self._BUFFER, end=2) @property def led_current(self): """The current of the LED. The value is in units of 10mA and can only be set to 0 (0mA/off) to 20 (200mA). See the datasheet for how LED current impacts proximity measurements. The default is 200mA. """ return self._read_u8(_VCNL4010_IRLED) & 0x3F @led_current.setter def led_current(self, val): assert 0 <= val <= 20 self._write_u8(_VCNL4010_IRLED, val) @property def led_current_mA(self): """The current of the LED in milli-amps. The value here is specified in a milliamps from 0-200. Note that this value will be quantized down to a smaller less-accurate value as the chip only supports current changes in 10mA increments, i.e. a value of 123 mA will actually use 120 mA. See the datasheet for how the LED current impacts proximity measurements, and the led_current property to explicitly set values without quantization or unit conversion. """ return self.led_current * 10 @led_current_mA.setter def led_current_mA(self, val): self.led_current = val // 10 @property def frequency(self): """ The frequency of proximity measurements. Must be a value of: - FREQUENCY_3M125: 3.125 Mhz - FREQUENCY_1M5625: 1.5625 Mhz - FREQUENCY_781K25: 781.25 Khz - FREQUENCY_390K625: 390.625 Khz (default) See the datasheet for how frequency changes the proximity detection accuracy. """ return (self._read_u8(_VCNL4010_MODTIMING) >> 3) & 0x03 @frequency.setter def frequency(self, val): assert 0 <= val <= 3 timing = self._read_u8(_VCNL4010_MODTIMING) timing &= ~0b00011000 timing |= (val << 3) & 0xFF self._write_u8(_VCNL4010_MODTIMING, timing) # Pylint gets confused with loops and return values. Disable the spurious # warning for the next few functions (it hates when a loop returns a value). # pylint: disable=inconsistent-return-statements @property def proximity(self): """The detected proximity of an object in front of the sensor. This is a unit-less unsigned 16-bit value (0-65535) INVERSELY proportional to the distance of an object in front of the sensor (up to a max of ~200mm). For example a value of 10 is an object farther away than a value of 1000. Note there is no conversion from this value to absolute distance possible, you can only make relative comparisons. """ # Clear interrupt. status = self._read_u8(_VCNL4010_INTSTAT) status &= ~0x80 self._write_u8(_VCNL4010_INTSTAT, status) # Grab a proximity measurement. self._write_u8(_VCNL4010_COMMAND, _VCNL4010_MEASUREPROXIMITY) # Wait for result, then read and return the 16-bit value. while True: result = self._read_u8(_VCNL4010_COMMAND) if result & _VCNL4010_PROXIMITYREADY: return self._read_u16BE(_VCNL4010_PROXIMITYDATA) @property def ambient(self): """The detected ambient light in front of the sensor. This is a unit-less unsigned 16-bit value (0-65535) with higher values for more detected light. See the :attr:`ambient_lux property` for a value in lux. """ # Clear interrupt. status = self._read_u8(_VCNL4010_INTSTAT) status &= ~0x80 self._write_u8(_VCNL4010_INTSTAT, status) # Grab an ambient light measurement. self._write_u8(_VCNL4010_COMMAND, _VCNL4010_MEASUREAMBIENT) # Wait for result, then read and return the 16-bit value. while True: result = self._read_u8(_VCNL4010_COMMAND) if result & _VCNL4010_AMBIENTREADY: return self._read_u16BE(_VCNL4010_AMBIENTDATA) # pylint: enable=inconsistent-return-statements @property def ambient_lux(self): """The detected ambient light in front of the sensor as a value in lux. """ return self.ambient * _VCNL4010_AMBIENT_LUX_SCALE