2nd reef-pi setup with robotank ph board loss of ph reads negative at time

[Wolfw28]

I setup a second pi4 with robotank script and robotank ph board do to the instability of ph reading with ESP32. All when as normal did the ph probe calibration seamed to be fine. Now the ph reading doesn’t drop out it drops to a negative number like -3.5ph and then back to reading normal. I have read just about ever post with no luck fixing the problem. One thing that’s odd but I think @robsworld78 updated his script. Because when you run sudo nano boot/config.txt it opens and the line that in previous post are not there. Actually what is there is all commented out (#) in front of ever line.

 

[Wolfw28]

I setup a second pi4 with robotank script and robotank ph board do to the instability of ph reading with ESP32. All when as normal did the ph probe calibration seamed to be fine. Now the ph reading doesn’t drop out it drops to a negative number like -3.5ph and then back to reading normal. I have read just about ever post with no luck fixing the problem. One thing that’s odd but I think @robsworld78 updated his script. Because when you run sudo nano boot/config.txt it opens and the line that in previous post are not there. Actually what is there is all commented out (#) in front of ever line.

 

[Wolfw28]

 

[Sral]

I would recommend using the config settings regarding the I2C settings, especially the line with the baudrate of 10000.

After you have hopefully fixed the dips that way you need to calibrate again. It looks to me that when you calibrated pH the error values might have skewed something.

 

[iamdan]

I have this same issue with two separate tanks running two robo-tank controllers running reef-pi v6.0

I lodged a ticket in Github about it https://github.com/reef-pi/reef-pi/issues/1977 on November 27 2022 and on Feb 2 i left a message asking Ranjib for any idea when this would be looked at and haven't heard anything.

Rolling back to older versions doesn't help me out as then it just breaks other functionality i have in use, so having this graph/ph reading that drops out is the lesser of the evils lol

 

[Wolfw28]

I would recommend using the config settings regarding the I2C settings, especially the line with the baudrate of 10000.

After you have hopefully fixed the dips that way you need to calibrate again. It looks to me that when you calibrated pH the error values might have skewed something.

Could you elaborate more on which config settings, and how to access them.The only ones I know is the one mentioned here.

Maybe verify a couple lines in the /boot/config.txt file. Here's the commands to run.

sudo nano /boot/config.txt

This will open a file, scroll down and find the following two lines.

dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=10000

It's possible these are on the same line separated by a comma, if so delete the comma and add a new line between them like above. Also check to see if there are duplicates of these lines.

Then press CTRL + S on the keyboard to save and then CTRL + X to exit. Then reboot the controller and the change will take effect.

Does the under voltage error happen the same time the pH dropped to 0? As there was under voltage reported I wonder if the main power supply for the controller is a little soft when a load comes on, do you see any correlation with equipment switching and that error?

My looks like this.

 

[iamdan]

Hi Wolfw28 - yes that is the correct info to set/verify the i2c settings. If you scroll down the config file does
dtparam=i2c_arm=on and dtparam=i2c_arm_baudrate=10000 show up? if not add it

 

[Wolfw28]

Thank you everyone for the help the dtparam=i2c_arm_baudrate=10000
was missing for some reason wasn’t sure if it was or was not the problem do to all the up grades and have had no problems with @robsworld78 reefpi install script on a fresh bullseye install. Not saying there a problem with @robsworld78 script just I always run into weird problems no one else seems to have.

 

[Sral]

No worries, these cases are the perfect feedback for developers to improve their products and themselves

 

[diver22]

Good day, I'm currently looking in adding a PH probe to my reef-pi running on Pie 3 B+, I do have a hat which allows me to add multiple things currently running my Vipra spectra lights off it but would now like to add PH probe, can anyone tell me what PH Pro board and probe would be good for this reef-pi software that I can plug into my a Pie 3 B+ HAT.

Any help would be great on what to buy would be great and any recommendations would be great.

 

[Sral]

Good day, I'm currently looking in adding a PH probe to my reef-pi running on Pie 3 B+, I do have a hat which allows me to add multiple things currently running my Vipra spectra lights off it but would now like to add PH probe, can anyone tell me what PH Pro board and probe would be good for this reef-pi software that I can plug into my a Pie 3 B+ HAT.

Any help would be great on what to buy would be great and any recommendations would be great.

Hi, the most common pH modules are, as far as I know, the ones from Atlas INstruments and Robo-Tank. SOme people do use analog boards from Aliexpress, DFRobot or similar, but I haven't heard much from those.

Both that I mentioned are connected by I2C, which can be a bit tricky due to cable length and interference.
The Atlas Instruments one needs a separate Isolator board, otherwise your measurements can go haywire from interference.
The one from Robo-Tank has Isolation integrated.

Both can in principle be used to measure ORP ( with an ORP probe connected) in a limited range (something like +/- 400mV). You simply have to take the pH value and let ReefPi do the following transform formula:
59.2 * (v-7)

As pH is also just measuring the voltage over the probe, with 0mV being a pH of 7.0 and each 1.0 in pH is a measurement of 59.16mV


Probes are a bit more difficult, I got a cheap no-name one from a local Aquarium store, @robsworld78 has been using some double layer ones, a double junction from apera instruments If I recall correctly.