Can't get EncPlex4067 to work with common ground only

[grbfst]

I have encoders connected to two 4067 boards. If I connect 3.3 volt to the encoders they work but without power (common ground) they don't. In the documentation it is stated that common ground should work. do I need to set a pinmode somewhere?

[luni64]

Common ground can only work if the encoders are directly connected to the Teensy which will provide the 3.3V (vcc) to the encoder. If you connect it through an 4067 you need to provide vcc. Here you find a validated schematic https://github.com/luni64/EncoderTool/tree/master/Resources/Extras#multiplexing-with-cd4067 showing how to use the 4067 which uses common vcc.