reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[trackerit]

So the plot thickens..

When I try run the line provided above I got a permissions issue which really shouldn't happen with pi and sudo.

I opened it with pico using sudo and when I try to save I get:

[ Error writing /sys/class/pwm/pwmchip0/pwm0/duty_cycle: Invalid argument ]

I also tried stopping the reef-pi service and that did not help.

So something is preventing us from updating the file.



No worries at all, we appreciate the work that went into this and the ongoing support. It is the nature of Pi projects to have occasional problems!

if change permissions same problem:
pi@raspberrypi:/sys/class/pwm/pwmchip0/pwm0 $ sudo chmod 777 duty_cycle
pi@raspberrypi:/sys/class/pwm/pwmchip0/pwm0 $ ls
capture duty_cycle enable period polarity power uevent
pi@raspberrypi:/sys/class/pwm/pwmchip0/pwm0 $ sudo echo 10000000 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle
echo: write error: Invalid argument

 

[trackerit]

ok, i try the version 2.2 of reef-pi and work fine, but with

So the plot thickens..

When I try run the line provided above I got a permissions issue which really shouldn't happen with pi and sudo.

I opened it with pico using sudo and when I try to save I get:

[ Error writing /sys/class/pwm/pwmchip0/pwm0/duty_cycle: Invalid argument ]

I also tried stopping the reef-pi service and that did not help.

So something is preventing us from updating the file.



No worries at all, we appreciate the work that went into this and the ongoing support. It is the nature of Pi projects to have occasional problems!

I installed version 2.2 and it works perfect, but ne 2.3 continues the problem

 

[ChrisNH]

Can confirm, same for me. Will move forward with 2.2 pending a fix for 2.3.

 

[Ranjib]

Can confirm, same for me. Will move forward with 2.2 pending a fix for 2.3.

@theatrus ^^ I suspect reef-pi/rpi pwm changes

 

[trackerit]

Can confirm, same for me. Will move forward with 2.2 pending a fix for 2.3.

@theatrus ^^ I suspect reef-pi/rpi pwm changes

how can i buy a
Reef-Pi Pico Controller Board (Revision D) ?????

 

[theatrus]

@theatrus ^^ I suspect reef-pi/rpi pwm changes

Quite likely. It’s possible the kernel driver gets in a weird state, hence the invalid argument error. The various knobs have to be knobbed in a specific order.

If you get in the state, try rebooting the whole Pi (reboot, not reload).

 

[rushbattle]

how can i buy a
Reef-Pi Pico Controller Board (Revision D) ?????

http://blueacro.com/controllers/picobeta

 

[trackerit]

http://blueacro.com/controllers/picobeta

[emoji17]

 

[rushbattle]

[emoji17]

Send [email protected] an email. He will get you all hooked up.

 

[bishoptf]

Quite likely. It’s possible the kernel driver gets in a weird state, hence the invalid argument error. The various knobs have to be knobbed in a specific order.

If you get in the state, try rebooting the whole Pi (reboot, not reload).

If I remembered @Ranjib made some updates to correct the issues @Bigtrout was seeing with the
PCA9685 pwm, which fixed those issues. I suspect something broke for the native rpi pwm, I'm running 2.2 and it works fine and never rolled to 2.3 since everything was working fine. I think the thing to call out is if using the pca9685 you probably want to use 2.3 and if using native rpi pwm use 2.2.

I was almost going to suggest that this weekend but didn't really think it would make a difference.

:)

 

[trackerit]

If I remembered @Ranjib made some updates to correct the issues @Bigtrout was seeing with the
PCA9685 pwm, which fixed those issues. I suspect something broke for the native rpi pwm, I'm running 2.2 and it works fine and never rolled to 2.3 since everything was working fine. I think the thing to call out is if using the pca9685 you probably want to use 2.3 and if using native rpi pwm use 2.2.

I was almost going to suggest that this weekend but didn't really think it would make a difference.

:)

So, if I use a pca9685 board would I have 16 channels? and if I use the native I will only have 2?

 

[Bigtrout]

So, if I use a pca9685 board would I have 16 channels? and if I use the native I will only have 2?

That is correct

 

[trackerit]

@theatrus ^^ I suspect reef-pi/rpi pwm changes

@Ranjib
Have you thought as well as the pH sensor add to monitor salinity? using the module EC EZO

https://www.amazon.com/Atlas-Scient...KP7WS0TY24Y&psc=1&refRID=FHNE50G7VKP7WS0TY24Y

 

[b4tn]

Just a doser reminder. Especially if you are using cheap Chinese peristaltic pumps. Set a timer to check calibration every so often. I have been dosing with reef-pi flawlessly for several months now. I did a random Alk test today and my levels where 9.6 from 8.4. I checked calibration on the pump and had to adjust it 10% slower to get back on track.

 

[Ranjib]

@Ranjib
Have you thought as well as the pH sensor add to monitor salinity? using the module EC EZO

https://www.amazon.com/Atlas-Scient...KP7WS0TY24Y&psc=1&refRID=FHNE50G7VKP7WS0TY24Y

EZO pH sensor is supported already. I felt the EC/Salinity sensor is not so important, given ATO is in place. Though it was not planned, I am actually working on getting the DO sensor support, because some folks in University of Alabamae is using reef-pi to monitor some experiments, they need it and I would love to support them.

 

[ludnix]

EZO pH sensor is supported already. I felt the EC/Salinity sensor is not so important, given ATO is in place. Though it was not planned, I am actually working on getting the DO sensor support, because some folks in University of Alabamae is using reef-pi to monitor some experiments, they need it and I would love to support them.

Oooh, maybe Reef-Pi will be listed in future journals under methodology! Thanks for making an effort to help the university!

 

[trackerit]

EZO pH sensor is supported already. I felt the EC/Salinity sensor is not so important, given ATO is in place. Though it was not planned, I am actually working on getting the DO sensor support, because some folks in University of Alabamae is using reef-pi to monitor some experiments, they need it and I would love to support them.

Great

 

[bishoptf]

EZO pH sensor is supported already. I felt the EC/Salinity sensor is not so important, given ATO is in place. Though it was not planned, I am actually working on getting the DO sensor support, because some folks in University of Alabamae is using reef-pi to monitor some experiments, they need it and I would love to support them.

UofA ughhhhh ;Yuck

;)

 

[Bzar]

So I took some time and figured out how to use regular float switches in a simple fashion using the built in pi resistors. This makes me happy because I don't have to have extra wiring and soldering tasks when adding a bunch of switches, and I don't have to pay for something I already bought. So to get regular float switches (or any switches for that matter) working safely you can do this...

Step A) create a python script to control the pull up resistance. From the terminal...

sudo nano switches.py

#switches.py
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)

GPIO.setup(21, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(20, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(16, GPIO.IN, pull_up_down=GPIO.PUD_UP)

ctrl+X > Y > <enter>

Step B) make the file executable...

sudo chmod 755 switches.py

Step C) make the script run at startup by adding a line just before "exit" in rc.local (note: the python start command must point to the directory from root /...

sudo nano /etc/rc.local

sudo python /home/pi/switches.py &

ctrl+X > Y > <enter>

Step D) Restart or Reboot

sudo reboot

Step E) Plug your float switch wires into the GPIO. One wire to Pi header connected Ground, and one to the GPIO you used in switches.py

Step F) Check to see if your script is running...

ps -aef | grep python

Step G) Designate those pins in Reef-Pi to inlets/ATO for your application.

Hope this helps, working for me here.

After doing some wire management I was having trouble stabilizing the Float Switch signal after reconnecting. There was some bouncing going on with the switches it seemed that would keep the switches always on, so I've added a software time mechanism to clear that up. I've also changed to having a python script for each float switch to keep things clean and easy. So a script for ATOfloat1.py, ATOfloat2.py, ATOfloat3.py, etc. Then add the scripts to rc.local again to start on boot. The new scripts look like this...

#ATOfloat1.py

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

GPIO.setup(21, GPIO.IN, pull_up_down=GPIO.PUD_UP)

while True:
    input_state = GPIO.input(21)
    if input_state == False:
        print ('ATOtank Fill')
        time.sleep(10)

In the code example there the float is connected to GPIO 21. Also there's a print command to see if it's working in the terminal. Hope this helps if anyone has issues where everything looks like it should be working, but the switches just wont turn off due to bouncing.

 

[Ranjib]

updates on the pico board ph test setup. There are three big observations:
- I am hitting some i2c issues, where the ADC ic is getting lost from i2c bus. persistently, after running several hours of monitoring at 1 min interval. I have manually verify this with i2cdetect -y 1
- Not sure why the millivolt reading is in negative, wrong byte read or something else..
- Also the trend is opposite. That time of the day , pH tend to go down.. I am not sure this is calibration will fix. We'll see. Can be bad probe . I am using american marine pin point probes ..bought from Amazon

Here is the four hour run for the sensor, before the i2c address was lost:

Around the breakage point:

I have rebooted pi and the i2c address for ADC reappeared., so sensor is sending data again. I'll see how it goes now. Meanwhile I'll start to put the ph board build in action some time this week. Stay tuned..

On the DO probe side, after reading through atlasscientific ezo circuit docs, I think reef-pi can read the DO probe as it is with ph driver code. So, if one does the do probe UART to I2c setup and calibration using the atlas scientific python code and then add the DO sensor as pH sensor in reef-pi, that should work. I'll see if I can get a sensor and ezo circuit , I have an extra voltage isolator and bnc probe (tentacle shield actually) ... but still its another 200-250$ :-O .