vl53l0x_multiple_sensors.py

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

"""
Example of how to use the adafruit_vl53l0x library to change the assigned address of
multiple VL53L0X sensors on the same I2C bus. This example only focuses on 2 VL53L0X
sensors, but can be modified for more. BE AWARE: a multitude of sensors may require
more current than the on-board 3V regulator can output (typical current consumption during
active range readings is about 19 mA per sensor).
"""
import time
import board
from digitalio import DigitalInOut
from adafruit_vl53l0x import VL53L0X

# declare the singleton variable for the default I2C bus
i2c = board.I2C()

# declare the digital output pins connected to the "SHDN" pin on each VL53L0X sensor
xshut = [
    DigitalInOut(board.D7),
    DigitalInOut(board.D9),
    # add more VL53L0X sensors by defining their SHDN pins here
]

for power_pin in xshut:
    # make sure these pins are a digital output, not a digital input
    power_pin.switch_to_output(value=False)
    # These pins are active when Low, meaning:
    #   if the output signal is LOW, then the VL53L0X sensor is off.
    #   if the output signal is HIGH, then the VL53L0X sensor is on.
# all VL53L0X sensors are now off

# initialize a list to be used for the array of VL53L0X sensors
vl53 = []

# now change the addresses of the VL53L0X sensors
for i, power_pin in enumerate(xshut):
    # turn on the VL53L0X to allow hardware check
    power_pin.value = True
    # instantiate the VL53L0X sensor on the I2C bus & insert it into the "vl53" list
    vl53.insert(i, VL53L0X(i2c))  # also performs VL53L0X hardware check
    # no need to change the address of the last VL53L0X sensor
    if i < len(xshut) - 1:
        # default address is 0x29. Change that to something else
        vl53[i].set_address(i + 0x30)  # address assigned should NOT be already in use
# there is a helpful list of pre-designated I2C addresses for various I2C devices at
# https://learn.adafruit.com/i2c-addresses/the-list
# According to this list 0x30-0x34 are available, although the list may be incomplete.
# In the python REPR, you can scan for all I2C devices that are attached and detirmine
# their addresses using:
#   >>> import board
#   >>> i2c = board.I2C()
#   >>> if i2c.try_lock():
#   >>>     [hex(x) for x in i2c.scan()]
#   >>>     i2c.unlock()


def detect_range(count=5):
    """ take count=5 samples """
    while count:
        for index, sensor in enumerate(vl53):
            print("Sensor {} Range: {}mm".format(index + 1, sensor.range))
        time.sleep(1.0)
        count -= 1


print(
    "Multiple VL53L0X sensors' addresses are assigned properly\n"
    "execute detect_range() to read each sensors range readings"
)