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Topic: Billie's Hydroponic Controller (Read 214361 times) previous topic - next topic


Hi Billie,

Thanks for the quick reply :-)

Is the pH Meter all the time into the water to measure the pH?

I had some information which sad that letting the ph probe all the time in the liquid will cause damage?

Perhaps this is wrong I only want to confirm it.

The pH probe is constantly in the nutrient tank. I haven't seen no degradation on the probe...

And second question : basically I only need one ph Probe and two peristaltic Pumps to setup a pH measure and adjustment station?
I have a Arduino UNO Board with max. 5V on the Digital Output with max. 30mA

I think you will be able to get that on the Uno. I don't have one, but since you are not using the TFT display and touch I think it will work...

I have found those two things now: http://www.aliexpress.com/item/Free-shipping-6V-DC-DIY-Dosing-pump-Peristaltic-dosing-Head-For-Aquarium-Lab-Analytical-water/1003369174.html

Those look ok to me. Another tip: When using silicone tubing (as in your pump) you have to use nitric acid instead of sulfuric acid. Because the latter will corrode the silicone tubing ;)

Do I can connect them directly to the board or do I need a extra power supply ?
No don't connect the pumps directly to the Arduino. You'll need a relay for that...Something like this one --> http://www.benl.ebay.be/itm/2-Kanal-5V-Relay-Relais-Module-Modul-fur-Arduino-PIC-DSP-PLC-TTL-/190698140291?pt=Elektromechanische_Bauelemente&hash=item2c667eb283

And as I have rad you divided the code so I can just take the part that fits?
Yes, it is modular, but you still need to think and debug for yourself ;)

And last but not least  :smiley-mr-green: : Why do you use a DC 9V plug for your arduino ? I thought 5V is max


The Arduino needs a power supply with a minimum of 6V and a maximum of 12V. So 9V is just in between ;)


Jun 22, 2013, 10:27 pm Last Edit: Jun 23, 2013, 02:16 am by Tonno Reason: 1
So another Time thanks for the reply

The relay inbetween the digital Output and the Pumps is only for the higher current right?

The 6V aren't still not supplied by the relay I think?

But anyway the pumps should also work without 6V , so 5V should be just fine you think?

The next few days I will look for a ph connection shield for the arduino and show it to you here in this thread to get the right piece :)

BTW Wehre did you geht your pH shield to connect to Probe from? I also live in Europe , ans the Shopping Costs from the States are really High

Thanks a lot in advance you are rellay helping me out a lot



Jun 23, 2013, 11:08 am Last Edit: Jul 16, 2013, 08:56 pm by BillieBricks Reason: 1
The relay should have it's own power supply. Both grounds from the Arduino and the power supply from the relay should be connected. You can run the relay with the power from the Arduino, but the pH shield is so sensitive that the on/off action from the relay messes the measurements from the pH shield. Also the peristaltic pumps need their own power supply because they need more current then the Arduino can deliver...
So in total you would need three power supplies -->1x 5V (relay); 1x 9V (Arduino); 1x 12V (Peristaltic pumps)
I bought my Phidgets 1130 in Germany last year. Because of the soccer world cup (or something) the owner of the shop would send it free of charge :D


Why not 6V for the pumps ?

6V power supplie can deliver 2 x times 6V or not?

12V could destroy the pumps or do I think wrong?

So basically i only have to care about the voltage the power supply can deliver ? Not about the current ?


My pumps where 12V, so that's why i needed a 12V power supply.
The relay and Arduino need two separate power supplies because when the relay switches on/off then a tiny current goes back to the Arduino and disrupts the pH reading the Phidgets 1130 makes...You'll see ;)


Okay so now I think I have all together I need

1 x Arduino Mega
1 x 9V external Supply for they Arduino

1 x 5V 2 Modul Relay
1 x 9V external Supply for the relay

1 x pH Probe With BNC connector
1 x pH Shield for the connection between probe and arduino
2 x peristaltic pumps
1 x external supply for the pumps

The probe will be connected directly to the ph shield for the arduino and the shield goes also directly to the arduino

The pumps will be connected to the relay and also to the external supply

What I don't understand is the connection of the relay,because it need to be connected to the arduino - will it simply be connected to the digital in / out pin? - as well as to the external supply and needs connection to the pumps is this right ?

Can you perhaps describe the way the relay will be connected to all these parts ?

I'm sorry for all the questions ... I'm hoping that's not so disturbing for you, perhaps this is a bit to heavy for my first project but anyway I will try it :)



Jun 24, 2013, 08:04 pm Last Edit: Jun 24, 2013, 08:15 pm by BillieBricks Reason: 1
It's actually a 5V adapter for the relay module. I made a mistake before ;)
You connect the VCC and GND from the relay to the + and - of the 5V adapter and the inputpin and GND from the relay to the Arduino GND and outputpin. That way your ground (GND) becomes what's called 'common'...
The output from the relay are 3 connectors per channel (NC and  NO) and are isolated from the input circuit. So you can even switch 120/230V AC if you like (But be careful if you do. Electricity is dangerous ;) )
You connect the peristaltic pumps to each channel per pump on the NO (normally open) connections together with the adapter in series... When you put your Arduino outputpin high the relay switches and current will flow making the pump turn...


Hey everybody,

It's been a while since my last update.
I was currently busy developing a shield for my controller. Since Eagly CAD doesn't agree with me it's taking quite some time...
In the meantime I found a cool website with lot's of information about the subject. He (Andrew) calls this the 'Arduarium Controller', but since this shield has everything my controller needs I'm trying to build it myself. You can buy the shield ready made, the bear PCB and Andrew even put the Eagle files on Github for people to use. The Eagle files are licensed under the TAPR Open Hardware License.

Meanwhile I have another short movie ready for you guys and gals to see the results from my controller. I foresee that the plants will reach the sealing within a month or so...



Thanks a lot for posting this great project! I feel the same way about sharing. If you want a copy of my CO2 controller code, let me know. Easy interface with any CO2 sensor: I used the analog out of my NOSE monitors (with humidity, temp, CO2 & webserver built in) to control a relay for fan & CO2 burner or tank. I think it would be a nice addition to your project.
Thanks again for posting -I'm just beginnning to read the posts but had to post on your comment about sharing. I'd love to see some open source grow software. Not just Arduino but PC too.
Damn - Now I'm going to be up all night...

PS - Here's a link to the NOSE monitor page. Not like you need the temp/humidity but it's nice to be able to check status via the webserver.
If you want one of the modules for half price, let me know.


Hey DX,

Thanks for your kind reply!! The purpose of this project was to create a low budget, open-source controller which could be used all over the world so people could improve their crop yield and have more money to spend on other things other then food...
Though this project is still in it's infancy I hope one day it will be used by many people.
And off course I'm interested to see your code so you'll soon get a pm from me :D
The screen shots from your web interface look very promising, though implementing CO2 wasn't initially in my plan. I looked it up for some idea's about it and one could build a CO2 generator for a very low budget...So thanks for pointing this out to me ;)
Will be looking out for some cheap CO2 sensors out there...

With kind regards,



This is awesome!

Any chance you could re-upload your most recent sketch?


Thx! :)
The latest one that's workable is already on-line ;)
Since the controller is doing it's job in the greenhouse I haven't updated it to check if the code is working properly...


Was that the filedropper link? It doesn't seem to be working (the link just takes me to their homepage)... Is it possible for you to reupload it?


Jul 23, 2013, 11:16 am Last Edit: Aug 30, 2013, 11:14 pm by BillieBricks Reason: 1
Oh I see...Here's a new link ;)

With kind regards,



Hi Billie

I've read through your thread, this project is very interesting.

Just a question regarding the temperature control problem with your fans switching on and off... (I cannot figure out how to place a quote here).

Where is your temperature sensor? (mounted high in your growing room, or down low?). I think that by mounting it up high, you would register a slower rate of temp change, as the colder air from the fans would fill the room from the bottom. Also, what about mounting a small fan to constantly blow air over the sensor, so that you get a more general temperature reading. I'm an aircraft mechanic, and in my experience, this is how various aircraft manufacturers rig up their cabin temperature sensors, in order to maintain a constant temperature. As soon as the fan stops, or the airflow over the sensor gets blocked by something, the temp control becomes erratic.

Just a thought, hanks again for a great project.

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