Here's the same thing for CircuitPython:

# SPDX-FileCopyrightText: 2022 Carter Nelson for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import time
import board
import adafruit_tca9548a
from adafruit_bme280 import basic as adafruit_bme280

# Create I2C bus as normal
i2c = board.I2C()

# Create the TCA9548A object and give it the I2C bus
tca = adafruit_tca9548a.TCA9548A(i2c)

#--------------------------------------------------------------------
# NOTE!!! This is the "special" part of the code
#
# Create each BME280 using the TCA9548A channel instead of the I2C object
bme1 = adafruit_bme280.Adafruit_BME280_I2C(tca[0])   # TCA Channel 0
bme2 = adafruit_bme280.Adafruit_BME280_I2C(tca[1])   # TCA Channel 1
bme3 = adafruit_bme280.Adafruit_BME280_I2C(tca[2])   # TCA Channel 2
bme4 = adafruit_bme280.Adafruit_BME280_I2C(tca[3])   # TCA Channel 3
#--------------------------------------------------------------------

print("Four BME280 Example")

while True:
    # Access each sensor via its instance
    pressure1 = bme1.pressure
    pressure2 = bme2.pressure
    pressure3 = bme3.pressure
    pressure4 = bme4.pressure

    print("-"*20)
    print("BME280 #1 Pressure =", pressure1)
    print("BME280 #2 Pressure =", pressure2)
    print("BME280 #3 Pressure =", pressure3)
    print("BME280 #4 Pressure =", pressure4)

    time.sleep(1)

With that code running on the CircuitPython board, the output will look like this:

Auto-reload is on. Simply save files over USB to run them or enter REPL to disable.
code.py output:
Four BME280 Example
--------------------
BME280 #1 Pressure = 1014.0
BME280 #2 Pressure = 1013.72
BME280 #3 Pressure = 1013.73
BME280 #4 Pressure = 1013.75
--------------------
BME280 #1 Pressure = 1013.99
BME280 #2 Pressure = 1013.72
BME280 #3 Pressure = 1013.76
BME280 #4 Pressure = 1013.73
--------------------
BME280 #1 Pressure = 1013.98
BME280 #2 Pressure = 1013.71
BME280 #3 Pressure = 1013.74
BME280 #4 Pressure = 1013.75

Again, there is little more done compared to the 3xBME280s example other than adding a new instance for the 4th sensor, specifying the TCA9548A channel:

bme4 = adafruit_bme280.Adafruit_BME280_I2C(tca[3])   # TCA Channel 3

And then using it like the others:

pressure4 = bme4.pressure

This guide was first published on May 04, 2022. It was last updated on May 04, 2022.

This page (CircuitPython) was last updated on May 13, 2022.

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