I don’t know why these measures are unstable.
i really need this a/d for connecting ec-ph modules and hall effect current sensor.
3.3v supply is stable, 5v fluctuates to 4.55 from 4.62.
I used both supply voltage for test.
I connected an old 5v usb battery
to raspberry but nothing changed.
Output from battery 4.98V - 5.03V
Output from raspberry (4.42V - 4.63V) and 3.28V stable.
Trying to supply ADS1115 with 3.3v, measures remains unstable.
There are a lot of things that can cause what you’re observing. It appears to be operating normally after seeing the accuracy when connected to a battery, so it is likely your power supply that is the issue. 4.6 V is also an insufficient voltage to power a Pi. Additionally, the circuit you’re using the ADS1115 in can have a significant effect on noise (e.g. does the circuit have ferrites?). Last, the number of measurements you have set to average also affects the ability of the software to smooth outlier measurements.
I have 3A 5V power supply and voltage is stable.
4.6V is the voltage in gpio pin for supply the ADS1115.
Stabilizer inside Raspberry lowers the voltage.
I found the problem right now.
i need two input modules for using your new PH/EC read function and at the same time use the remains two input for other purposes.
But clearly that’s not possible.
So, deactivating one of two modules, measurements become stable.
Do i need to buy another ADS1115?
You can create a new Input with pH/EC measurements and voltage from the other 2 channels. Open each Input to learn how they both work and take the relevant parts from each. Import your new Input and you’re good to go.
The problem is exactly this.
I am already using two inputs for the same ADS1115 and this cause conflicts.
If you integrate all 4 ADS inputs in PH/EC would be better, i think.
But i can solve it by using another ADS.
it also not possible set the number of measurements to average in PH/EC inputs.
I have another big problem, i don’t know if i should open a new post for this.
Using PH/EC input i can’t calibrate the probes.
Here is the voltages…
I don’t know, is it normal?
after calibrating PH4 and PH7, if i measure PH6, this is totally out of range.
Same thing for EC
i think this is another reason to create the custom inputs that i didn’t understand.
Could you explain to me?
Do you talking about rescale method with equation?
Just jumping in here. This part number appears to be for a TDS probe, not an EC probe. I know the working principles are similar, but without knowing exactly how this TDS sensor board is designed it’s hard to know what is going on. In the EC probe that I used to prototype the pH/EC custom input, the EC sensor board perturbs the pH measurement and must be modified to filter out the galvanic offset. I made a post about it on the old forum here.
Not sure what this means. Are you trying to power ADS1115 from the Raspberry Pi GPIO pin?