Sodaq One & multiplexer crosstalk problem


I am using a Sodaq LoRa One rev 4 and 2x CD74HC4067 multiplexers. The multiplexers are using 10 pins in total and here is the pinout:

Sodaq - Mux
A0 - S0
A1 - S1
A2 - S2
A3 - S3
A6 - Z

Second mux pinout:

Sodaq - Mux
A7 - S0
A8 - S1
A9 - S2
A10 - S3
A11 - Z

On the second mux I am seeing a lot of crosstalk and it seems the cause is the pins A7 - A11 that the mux is using. I know for sure because I changed the pins of the 2 mux’s with each other and that’s when the other mux started to have crosstalk issues. Can someone tell me whats up with pins A7 - A11

P.s. Pins A12 and A13 I am controlling MOSFETs, so those pins are also used for something.



I changed the Z pin of the second mux from A11 to A12 and that fixed the crosstalk issue. I believe there is something wrong with pin A11, either with the ADC or the pin doesn’t get read fast enough.

There is some labelling confusion on the schematic vs the Arduino number.

Could specify which pins you are using on the J1/J2 headers from the schematic:

I’m sorry, I have no idea what the J1/J2 headers are. On the board I use pins A0-A3, skip the I2C pins and use A6-A11. A12 and A13 are also unused. I wired everything according to the schematic provided here: