DIY arduino CO2 bubbler in lieu of group buy one

[AlanM]

Since javelin got the brush off on his plant regulator group buy, I'm serious about building a DIY version for club folks if they want them. So far I have the 12v valve and fittings which screw into a CO2 regulator and has a 1/8 barb output for airline to connect to:

 

 

I also have an Arduino, a 12v power adapter, resistor, transistor, diode combo which should let me switch the 12v power to this solenoid on and off using the 5v output of the arduino output high/low pins. It will accept 10V VDM input or a knob to control the bubble rate. I'd like to add an LED or two to flash when it bubbles too. I'll be asking Tom to check my electronics/math and may have a prototype at the meeting.

 

If this thing works, and I can get them made for substantially less than $100, who would be interested in them? Just trying to gauge interest because the valves are cheaper if you buy a bunch.

[AlanM]

Actually, I think I will also write code for the Storm X so that one of the channels could do CO2 at different rates during the day.

[lnevo]

I'm not interested in a purchase now but if I ever go with a co2 reactor I would definitely be interested in this build!!

[ctenophore]

Hey Alan, count me in for one. I want to use something like this for a phytoplankton reactor I'm working on. Let me know how much to send you. Any chance you can make one with multiple outputs?

[AlanM]

I'd skip the arduino entirely and just run the 12V solenoid right into a 12V relay expansion if I had a Reef Angel running it. 8)

[AlanM]

Hey Alan, count me in for one. I want to use something like this for a phytoplankton reactor I'm working on. Let me know how much to send you. Any chance you can make one with multiple outputs?

Yep. If I get one running it will be easy to have a bunch off the same arduino. Would need multiple knobs to set multiple bubble rates, heh.

[YHSublime]

I'm not interested in a purchase now but if I ever go with a co2 reactor I would definitely be interested in this build!!

This

[s2nhle]

I may interest in this one.

[Origami]

Alan, why all the smarts in the box? Why not just run a 555 timer as an pulse train generator with a variable pulse rate, tied to a switched / timed outlet? This is pretty much the way the commercial product behaves, I believe, and can be readily integrated into systems using either a pH controller or an aquarium controller.

[AlanM]

Alan, why all the smarts in the box? Why not just run a 555 timer as an pulse train generator with a variable pulse rate, tied to a switched / timed outlet? This is pretty much the way the commercial product behaves, I believe, and can be readily integrated into systems using either a pH controller or an aquarium controller.

Well, partially I'm using the smarts in the box because it's only $20 and easy to do and easy to support lots of different input and output. Just a timer chip is already $2 plus a pile of other stuff that I'd have to experiment with and possibly discard from RadioShack. Also, Arduino I know, electronics I don't. Lastly, I think the way you're talking about integrating it is using an outlet that turns the entire thing on and off via the controller. I was planning to have it vary the bubble rate based upon the voltage that the controller delivered, not via an on/off control. Maybe that's too complicated, though.

[AlanM]

So it works. 

 

I'm using a SainSmart Nano board and Clippard Mouse solenoid with an stock 12V power supply and using a mono 1/8" stereo plug to send the 12V to the solenoid.  At the moment I'm using a 500 Ohm pot to change the bubble rate on it, but any pot will work.  On the following video you can see my terrible soldering job on the prototype and if you turn the sound up you can hear the clicking sounds that the solenoid makes as it opens and lets a bubble out.  It should be possible to do up to 8 solenoids with different bubble rates controlled by 6 pots mounted in one box and running off 1 Arduino.

 

 

Fun.

 

I also discovered that they sell a nice cord for connecting to the solenoid at http://www.clippard.com/part/ET-C48

[AlanM]

Much cleaner now.  Works on Apex or with knob.  The mini-USB plug is exposed, so it can be reprogrammed.  Not the nicest box ever, but everything fits ok.  Sending this one to Javelin.  Making a 3 channel one for Justin. 8)  I'm enjoying figuring it all out.

 

[ctenophore]

This has probably just become the nicest co2 control system available in the hobby. I saw it today and Alan is overly modest. It looks nice, made from quality components, in a slim little box and a feature set that is way better than anything out there and the capacity to be even better. We even talked about using par meter input to control co2 rate, as I might do while using it on my phyto reactor (which I just got about 90% done this afternoon after Alan came over with the co2 controller)

[Origami]

Alan, this is great what you've done. Draw it up when you get the chance.

 

Sent from my ADR6425LVW using Tapatalk

 

 

[dave w]

Alan, I'm really interested in how this works for you.  Like Justin, I'll be using CO2 input into my phytoplankton reactors and had considered adding CO2 during daylight hours, but your control system would be much more precise.  I'd like to see it sometime.  I'm using Arduino Megas and they have lots of room for multiple outlets.

 

Keep up the good work.

[monkiboy]

awesome work alan!

[AlanM]

This has probably just become the nicest co2 control system available in the hobby. I saw it today and Alan is overly modest. It looks nice, made from quality components, in a slim little box and a feature set that is way better than anything out there and the capacity to be even better. We even talked about using par meter input to control co2 rate, as I might do while using it on my phyto reactor (which I just got about 90% done this afternoon after Alan came over with the co2 controller)

Thanks for the nice words, Justin. I should have yours done this week. I'll be really interested to see if we can get that PAR meter input to work. Since your phyto is going to be in the sunlight it seems like that would be a much more reasonable way for you to run it than off Apex or timer.

 

Alan, this is great what you've done. Draw it up when you get the chance.

 

Sent from my ADR6425LVW using Tapatalk

I have most of the circuit drawn. I need to add the loops for the inputs, pot and Apex input.

 

Basically, Arduino gives you a 5V regulated output to use, so I put a pot between that and ground and send the swiper to one of the analog input pins. I read that pin and scale the number to give me a number of milliseconds between open/close events. Then I set one of the digital output pins to high (5V) when it needs to be open and low (GND) when it needs to be closed and send that signal through a resistor->LED->2N2222 base.

 

Then I have the 12V for the solenoid running through collector->emitter on the 2N2222 with a diode across the solenoid to prevent the off-current from blowing the transistor.

 

I run the Apex input through a voltage divider to drop it to 5V (just two 10k resistors in series) and send the voltage across one of the two resistors to another analog input pin and do the same measurement.

 

If there is anything on the Apex, I ignore the pot, if the apex is within 20mV (just an arbitrarily picked noise threshold) of 0 then I go with the pot.

Alan, I'm really interested in how this works for you. Like Justin, I'll be using CO2 input into my phytoplankton reactors and had considered adding CO2 during daylight hours, but your control system would be much more precise. I'd like to see it sometime. I'm using Arduino Megas and they have lots of room for multiple outlets.

 

Keep up the good work.

This is an Arduino Nano (Actually a Sainsmart Nano-compatible which is cheaper and comes with extras like USB cable and ribbon cable) which has 8 inputs and more than that outputs. Surprisingly lot for a board that size. I'll post up how it works.

awesome work alan!

Thanks Marco. I'll make you one with a box made of glowing green acrylic. 8) Actually, I considered making the LED indicator a UV one just for fun.

 

Edit: One change I really need to make is lowering the current on the indicator LED. It's a blue one that I'm running 20mA through, and it's shockingly bright when it flashes. My guess is Javelin911 ends up putting tape over the indicator on this prototype. I think 5mA would be sufficient, heh.

Edited April 13, 2014 by AlanM

[lnevo]

For the record theres an I2C compatible PAR meter being released by Reef Angel.

 

This is pretty cool Alan. If I ever go Co2 reactor I would definitely look to build one of these!

[AlanM]

Nice, Justin said he had a reef angel so maybe that would work

[javelin911]

looking forward to messing with this.  Having manual or APEX will work great while I transition equipment from old tank to new tank (APEX is on old tank right now). 

I don't think the light will bother me.  I have a new fish room that will keep the light out of view for most people and will have a wall of electronics etc.  Besides people like blinky lights!