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

[Ranjib]

Totally following should you decide to post any examples of your setup and/or scripts used on the arduino to do the translation!! Which pH probe are you using?

Without galvanic isolation, this will be highly unreliable, in our experience. My reading would fluctuate a lot when I tried read ph signal directly,

 

[AbjectMaelstroM]

Has anyone used these dosing pumps with Reef pi? Or known if they would be compatible?

New Dosing Pump Peristaltic Pump With 42 Stepper Motor Tubing Hose Pump | eBay

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[Ranjib]

Has anyone used these dosing pumps with Reef pi? Or known if they would be compatible?

New Dosing Pump Peristaltic Pump With 42 Stepper Motor Tubing Hose Pump | eBay

Find many great new & used options and get the best deals for New Dosing Pump Peristaltic Pump With 42 Stepper Motor Tubing Hose Pump at the best online prices at eBay! Free shipping for many products!

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Not yet, but I would love to. Is available from amazon?

 

[AbjectMaelstroM]

Not yet, but I would love to. Is available from amazon?

This might be like it. Has a head only and +stepper motor assembly.

Amazon product

Another one.
Amazon product

 

[Ranjib]

hm 5$ extra than ebay, not bad at all. I'll get it and test out. Thanks for the link. Its been long pending.

 

[AbjectMaelstroM]

hm 5$ extra than ebay, not bad at all. I'll get it and test out. Thanks for the link. Its been long pending.

Can't wait to see the results. I was thinking about using those instead of gutting a slave doser unit. Looks like those are wire for +/- in one direction and +/- in reverse direction. Is there any reason to wire "reverse"? I don't imagine I'd ever need to draw water from the tank....

 

[Ranjib]

Can't wait to see the results. I was thinking about using those instead of gutting a slave doser unit. Looks like those are wire for +/- in one direction and +/- in reverse direction. Is there any reason to wire "reverse"? I don't imagine I'd ever need to draw water from the tank....

From my primitive understanding, we can use reef-pi as it is, with stepper motors. We have to connect pi or pca9685 pwm pin to a stepper drivers (such as drv8835) and that should be it.
Reversing the motor direction is very common. The titration systems definitely use those capabilities. From a manufacturing and electronics perspective, H-brige drivers (a type of circuit that allows easily switch the polarity of motors) are very common and omnipresent in most stepper/dc motor equipment. I guess from manufacturing point of view its hard to know if this feature will be used or not, but given the prevalence (and cheap) of this capability, its safer to just have it.
It will be awesome if @theatrus, @Bigtrout or @Michael Lane can validate my assumption, beforer i embark on testing this setup ;-)

 

[rushbattle]

From my primitive understanding, we can use reef-pi as it is, with stepper motors. We have to connect pi or pca9685 pwm pin to a stepper drivers (such as drv8835) and that should be it.
Reversing the motor direction is very common. The titration systems definitely use those capabilities. From a manufacturing and electronics perspective, H-brige drivers (a type of circuit that allows easily switch the polarity of motors) are very common and omnipresent in most stepper/dc motor equipment. I guess from manufacturing point of view its hard to know if this feature will be used or not, but given the prevalence (and cheap) of this capability, its safer to just have it.
It will be awesome if @theatrus, @Bigtrout or @Michael Lane can validate my assumption, beforer i embark on testing this setup ;-)

I am afraid @theatrus is not engaged with reefing for a while now. Perhaps he’s busy, I hope for that and not health issues, or anything else.

 

[Michael Lane]

From my primitive understanding, we can use reef-pi as it is, with stepper motors. We have to connect pi or pca9685 pwm pin to a stepper drivers (such as drv8835) and that should be it.
Reversing the motor direction is very common. The titration systems definitely use those capabilities. From a manufacturing and electronics perspective, H-brige drivers (a type of circuit that allows easily switch the polarity of motors) are very common and omnipresent in most stepper/dc motor equipment. I guess from manufacturing point of view its hard to know if this feature will be used or not, but given the prevalence (and cheap) of this capability, its safer to just have it.
It will be awesome if @theatrus, @Bigtrout or @Michael Lane can validate my assumption, beforer i embark on testing this setup ;-)

It sounds like you have it right. Stepper motors are driven by alternating magnetic fields, so it's a bit more complicated than using a DC motor. The stepper driver will control moving those fields with each pulse.

 

[Ranjib]

It sounds like you have it right. Stepper motors are driven by alternating magnetic fields, so it's a bit more complicated than using a DC motor. The stepper driver will control moving those fields with each pulse.

As I am reading through, it seem like the duty cycle does not matter that much (anything above 50% is good) and I have to actually change the pwm frequency to change the speed of the stepper motor. I am ordering a DRV8825 driver and that 33$ stepper motor based doser for testing. Thanks for checking :-) . I'll keep you all posted

 

[MrWheelock]

Can't wait to see the results. I was thinking about using those instead of gutting a slave doser unit. Looks like those are wire for +/- in one direction and +/- in reverse direction. Is there any reason to wire "reverse"? I don't imagine I'd ever need to draw water from the tank....

Auto water change

 

[Ranjib]

I am afraid @theatrus is not engaged with reefing for a while now. Perhaps he’s busy, I hope for that and not health issues, or anything else.

Hmm.. Life can get busy.

 

[buddy.]

Does anyone know what this email alert is caused by? The probe is still working so I am not sure why it says it failed.

 

[AbjectMaelstroM]

Does anyone know what this email alert is caused by? The probe is still working so I am not sure why it says it failed.

Looks like it's no longer registering the temp probe labeled "sump".

Check connections/probe, could be a dead probe.

 

[buddy.]

Looks like it's no longer registering the temp probe labeled "sump".

Check connections/probe, could be a dead probe.

The weird thing is that the probe never actually stops working according to my graphs on the dashboard.

 

[AbjectMaelstroM]

The weird thing is that the probe never actually stops working according to my graphs on the dashboard.

Does it actually register temp changes or displays the same temp it read last? When I was playing around with my build, I saw that same message when I disconnected Temp probes with pi running. It continued to display temp reading, but it didn't register changes, but continued the last temp reading.

I would check make sure the probe is functional and registers temp changes.

 

[Ranjib]

Some updates on the wave maker test. On a sad note, the 12V submercible pumps were not variable speed. They didnt run on PWM signal. I dont know if they would rather respond to analog (0-12V) or they are just fixed speed. I'll figure it out later, if they do work in analog speed, I'll take the analog path on ciruit side.

But even without the PWM support, I was able to kinda use those pumps straight by supplying entire 12V. The way I did was pretty simple, just disable pwm module in kernel config, declare GPIO 18 and 18 (which is feeding L293d en1/en2 pins) as normal outlets in reef-pi and instead of pwm profile, use timers. Though I dont have the variable speed features, now with switching offloaded to l293d, I can do lot more aggressive (5 or 15 second pulses) without worrying about relay's failing or click noises. I am planning to use this as wavemekar, as intended, but with times instead of pwm profiles. I have tested my dosing heads also, and they work just fine. Which means I can use this exact controller to control any two dosing pumps. All of this will only involve couple of software tweaks. The hardware/circuit/enclosure is reusable as it is. I like this.

Pumps: Amazon product


Build

Tank and pumps (ignore the clutter :-))

The dosing unit

I made a handy male -male barrel connector for pump or dosing unit
Off to the next set of things ...

 

[Ranjib]

Does anyone know what this email alert is caused by? The probe is still working so I am not sure why it says it failed.

It means the sensor reading has failed crc check. Sometime this happens due to bad probe or connection issue , which results in data corruption causing failure in checksum . Pi indicates this by “yes” when checksum verification pass. Reef-pi is just showing that error , and complaining that it’s expecting a yes at the end of the reading file. This also means the sensor is present and detected , and reef-pi is also able to read it.

 

[buddy.]

It means the sensor reading has failed crc check. Sometime this happens due to bad probe or connection issue , which results in data corruption causing failure in checksum . Pi indicates this by “yes” when checksum verification pass. Reef-pi is just showing that error , and complaining that it’s expecting a yes at the end of the reading file. This also means the sensor is present and detected , and reef-pi is also able to read it.

Thanks @Ranjib . Do you mean a physical wiring connection or something to do with the data connecting?

I am also getting these email alerts occasionally. Also sometimes a negative temperature of something silly like -1000 degrees. Temps are in C.

Here is my temperature page in reef-pi. Does it look correct? Just ignore all of the graph before the heater readings, this was when I had a failed probe. You can see the spike where it alerted me to 85 degrees.

 

[Bigtrout]

Those spikes look similar to what i was getting when i had the wonky power supply throwing interference.

@Ranjib means the data is getting corrupted occasionally. This could be from loose wiring, or some type of interference. Check and double check the wiring. Also check the routing of your sensor wiring. Keep it away from any AC wiring or motor/pump wires.