Sodaq One & multiplexer crosstalk problem

ONE
1

Hi,

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.

Regards,
Fritz

2

Update:

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.

3

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:
http://support.sodaq.com/sodaq-one/schema-sodaq-one/

4

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: http://support.sodaq.com/sodaq-one/sodaq-one/.