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

jasttestin · November 30, 2021, 3:30pm

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.

github.com

DexterInd/GrovePi/blob/master/Software/Python/grove_ph_sensor.py

#!/usr/bin/env python
#
# GrovePi Example for using the Grove PH Sensor (http://www.seeedstudio.com/wiki/Grove_-_PH_Sensor)
#
# The GrovePi connects the Raspberry Pi and Grove sensors.  You can learn more about GrovePi here:  http://www.dexterindustries.com/GrovePi
#
# Have a question about this example?  Ask on the forums here:  http://forum.dexterindustries.com/c/grovepi
#
'''
## License

The MIT License (MIT)

GrovePi for the Raspberry Pi: an open source platform for connecting Grove Sensors to the Raspberry Pi.
Copyright (C) 2017  Dexter Industries

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

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jimrh · November 30, 2021, 5:57pm

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.