PH Sensor (E-201C-Blue) - Where to place the NC & SIG outputs on the analog to digital converter (ADS1115)

Hi! I’ve bought this pH sensor (E-201C-Blue), and I’m currently trying to get this working with use of this (also link below) library:

I’m using an ADS1115 (analog to digital) converter to get this working, and the pH sensor comes with the following outputs: VCC, GND, NC, SIG (like shown in the GitHub repository).

In the GitHub repository, it states: “Connect the Grove PH Sensor to analog port A0”.

Now I’m wondering what exactly needs to be connected to A0? Does this mean I need to connect both the SIG and NC to the A0 port on the ADS? Or does this mean I need to make use of A1 too?

Thank you in advance for any help.

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OK, a couple of points to note:

First of all:

This sensor and all it’s problems, has been extensively, (and possibly exhaustively), discussed here:

This thread is quite long and contains a lot of excellent information.  However the entire thread can be effectively summarized by saying that this sensor is, in essence, a toy and cannot be trusted to give accurate readings, no matter what you do.

Please read this thread and try some of the suggestions mentioned there.

VCC - Power.  Possibly +5 vDC, because Grove is mostly +5, though I would check.
GND - Power and signal return.
SIG - The output signal itself.
NC - “Not Connected” - an unused pin that is not connected to anything.


Give this stuff a look, try some of the things others have suggested, and then come back here and tell us what happened.

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