Interfacing with an SDI-12 Sensor

Hello All,

I am looking for some help interfacing with an SDI-12 sensor. Specifically the Hydrolab Quanta Sensor. I know that this topic has been posted before, but after some tinkering I just cannot get it to work.

I used joranbeasley’s SDISerial library to no avail. I’ve checked with an oscilloscope that the correct message is being sent. Has anyone else had issues with it?

I’m wondering if maybe my wiring is wrong? The manual for the Hydrolab Quanta isn’t very clear. I have attached a screenshot of part of it below. It appears to me that all of the grounds should either be connected to the same ground, or that the bare wire and yellow wire should be connected to the Arduino ground and the red wire should be connected to the power source ground, but none of these setups are working.


Aware that logical 1 is 0V ?

Yes. I have the display module that attaches to it and connected the oscilloscope to the data connection on that one and it is sending out the exact same waveform I'm using the Arduino to send. The only difference is that the display's sent signal is getting a response while the Arduino is not.

Verify that address is the same ? I saw this

Yes, I have confirmed that the address should be 0.