Qwiic MUX Hookup Guide
Englandsaurus 
Troubleshooting Tips
Here are a few tips for troubleshooting this device.
No Available Devices
Double check your connections. On a Raspberry Pi, you may get this is indicated with an OSError: [Errno 121] Remote I/O error readout.
On a Raspberry Pi, also make sure that the I2C hardware is enabled. This is usually indicated with an Error: Failed to connect to I2C bus 1. readout.
Checking Your I2C Connection
A simple method to check if your Raspberry Pi can communicate over I2C with the Qwiic Mux, is to ping the I2C bus. On the latest releases of Raspbian Stretch, the i2ctools package should come pre-installed. If it isn't run the following command in the terminal:
sudo apt-get install i2ctools
Once the i2ctools package is installed, you can ping the I2C bus with the following command in the terminal:
i2cdetect -y 1
You should see a table printed out in the terminal. If the Qwiic Mux is connected/working properly you should see the address space for 0x70 marked with 70.