MUX board problem

EMU BLACK / CLASSIC
1

Hello everyone,

I recently ordered a MUX board from my local Ecumaster supplier.
I then wired everything up (3d printed a nice enclosure for it), only to find out that the default state of all (MUX)switches is ON. I checked the wiring (+5v, AIN, GND), all is fine.

I then took the board out again and started measuring on the board itself. Below is schematic diagram of the board.

MUX
MUX1012×829 98.6 KB

If I measure across +5v and SW1, I should measure 12.200Ohm’s of resistance, right?
Likewise, If I measure between +5V and SW2, I should measure 6.900Ohm’s of resistance.
However, I’m measuring about 10K ohm on all three circuits.

So, I ordered another board from Ecumaster…same thing.
Am I missing something or is the second board also bad?

Regards,
Ramon

2

Measure ground to analog in

4

Hi,

Thanks for the reply.
I measure about 6.3K ohm between GND and AIN on all three switches.

5

Hi
The picture u posted is how to setup a mux switch by urselfe without the board.
For the mux board u need to wire it like that:

Screenshot_20241026-170755_Adobe Acrobat
Screenshot_20241026-170755_Adobe Acrobat1080×2640 122 KB

Did u consider this?

6

Hi,

That is exactly how my MUX is wired. It is essentialy the same as the schematic I posted above.

7

U are right…just asking. Cause if u wire the mux board like in the emu scematics there is the risk that u connect sensor ground to a other ground and read nothing.

8

You have enable 4.7k pull down at this analog input thats why you measure 6.9k.

9

I’m using 1M pull down on analog 4. With the 4.7k pull down, it doesn’t work either.

10

You need pull up not pull down

11

I don’t think so. I tried it anyway, and it makes no difference.
I still have 1.8v on analog 4 with all switches off…there’s definitively something wrong with the board.