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SDI12-sensor + MUX on CR300 ?

Rabah DJEDJIG Apr 16, 2021 08:11 AM

Dear all,

I have a CR300 to which a WXT530 weather station is connected via SDI-12 communication. The C1 control channel is used for this purpose.
I would like to know if it is possible to connect in addition an AM16/32B multiplexer. This multiplexer will have to use the only two existing control channels C1 and C2. Is it possible to use the C1 channel for both connections at the same time ?

Thank you,

pokeeffe Apr 22, 2021 09:51 AM

I've had success using C2 for state detection (0/5V) while C1 does SDI-12. The mux needs 1 control channel for `RES` and another channel for pulsing `CLK`. You can't reuse C1 but if P_SW is free try using it with `PulsePort()` for clocking and connect `RES` to C2.

Rabah DJEDJIG Apr 23, 2021 01:11 AM

Thank you !

smile Apr 24, 2021 12:46 PM


I don't think it can work. The P_sw terminal is an input for contact closure impulse sensors such as rain gauge or several anemometers. The P_SW terminal cannot generate output pulses towards the multiplexer

Instead, I would test with a VX1 or VX2 channel.


pokeeffe Apr 27, 2021 02:10 PM

For the CR300, the P_SW terminal can also be a digital output. The VX channels might work too but they are not supported by the `PulsePort` instruction: https://help.campbellsci.com/crbasic/cr300/#Instructions/pulseport.htm 

smile Apr 28, 2021 09:23 AM

OPS! Sorry 

there is always time to learn new things!

Thanks so much


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