Multiple Qwiic ICM20948 sensors with Qwiic Mux Breakout TCA9548A

Qwiic System
1

Hello,

I am encountering a problem when trying to read data from multiple Qwiic ICM20948 sensors attached to different channels of a Qwiic Mux Breakout TCA9548A. The problem is that only one Qwiic ICM20948 sensor appears in the list_devices.

Running the following code:

test = qwiic.QwiicTCA9548A()
test.enable_all()
results = qwiic.list_devices()
print(results)

I get as output:

[(105, ‘Qwiic ICM20948’, ‘QwiicIcm20948’), (112, ‘Qwiic Mux’, ‘QwiicTCA9548A’)]

despite two sensors are connected (one to channel 0 and one to channel 1).

How can I access both sensors and simultaneously read from them?

Thank you for your help.

2

You can’t. You must select one channel and read that sensor then select a second channel and read that sensor.

If you connect both sensors at the same time their i2c address will conflict with one another since they have the same address.

3

Thank you very much. I wrote the folling code and it seems to work. However, the delays are approx. 0.02 seconds per cycle. Is there a more efficint way to read the sensors to reduce the delay? Thank you very much

test = qwiic.QwiicTCA9548A()
test.disable_all()

test.enable_channels([0])
IMU = qwiic.create_device('QwiicIcm20948')
if IMU.connected == False:
    print("The Qwiic ICM20948 device isn't connected to the system. Please check your connection", \
    file=sys.stderr)
else:
    IMU.begin()
test.disable_channels([0])

while True:
    test.enable_channels([0])
    if IMU.dataReady():
        IMU.getAgmt()
    test.disable_channels([0])

    test.enable_channels([1])     
    if IMU.dataReady():
        IMU.getAgmt() 
    test.disable_channels([1])