4067 Mux, Ariadne & Ethernet Incorrect Mux Values?

I’m very new to Arduino’s and attempting to set a couple up for a project where only network communication is available. I’m using an Arduino Uno with an Ethernet shield to monitor a collection of sensors including 5 DHT22 temp/humidity sensors 2 water level (leak detection) and 10 voltages. I’m monitoring the voltages via a CD74HC4067 16 channel mux. I need the ability to update sketches remotely via network connection so I’m using the Ariadne bootloader.

Independently I’ve built sketches to interface with each of the various sensors and the mux and all appear to function fine on their own. However when I build a sketch to incorporate all the sensors I run into problems with the mux when I start the ethernet server commands. Everything compiles and uploads correctly but the mux starts reporting incorrect values (noise values, bouncing within the correct range 0-1023 but incorrect). When I run my sketch that reports the mux values independently (no network interfacing) I get good results with all the sensors wired up on my test platform.

I’ve tried using different libraries for the 4067 in case there is some conflict but all yield the same result. Is there something inherently wrong with my approach or some incompatibility between the 4067 and ethernet operations?

I’ve attached a simple sketch that I’ve been using for testing. In the version attached the mux works as expected if I uncomment the lines that are prefaced with //******** the mux will report incorrect values.

What am I missing here? Any help would be appreciated.

Thanks,
Brent

Mux_And_Ethernet_Test.ino (2.79 KB)

What am I missing here?

A schematic so we can see how things are wired.

some incompatibility between the 4067 and ethernet operations?

No.