DIY CHEAP DIY microcontroller (arduino) grow room environment controller

[captain budseye]

Hi,
I've just been looking at DIY grow room controller projects on websites like instructables. I had a quick flick through the DIY section here and i couldn't find a thread on this concept anywhere.

For those of you who don't have experience with electronics, I can tell you that arduino makes programming basic controllers incredibly easy, especially since it is fully open source and the whole premise is for people to share their code with others who lack the interest and knowledge to learn it themselves. Armed with the right code and a bill of materials ANYONE can build a project like this.

Currently I don't have time amongst everything else to embark on this project, got too many other projects on the go plus work plus study. However in the (probably distant future) I am definitely going to build a microcontroller based grow room controller. With all the cheap, (usually good quality) sensors and other electronic components on ebay from china, this could reduce the cost of expensive environmental controllers to a few tens of £'s, rather than 100's.

i thought I'd start this thread to see if people are interested. I have basic knowledge of the electronics and programming and can answer some questions.

I also thought if enough people are interested it could be a good idea to start a thread to build a reference of parameters to test/use when building these kind of systems drawing from more experienced growers who have thoroughly experimented with environmental control. E.g. Amount of water to feed plants at different stages of growth for different feeding schedules, light setup, auto/photo. Amount of co2 present, temperature, pressure etc.

Again I apologise but I just don't have the time right know to dive into this and actually carry out this project, but this could be a really powerful and inexpensive tool for those who are interested.

Let me know what you all think, I'd love to see a discussion evolve and bounce some ideas about.

 

[KsjAuto]

Nice Thread.
I was thinking about a thread like this Growrelated arduino stuff
Im all new to arduino. I thought many times on a full automated grow, tjecking ppm ph e.t.c on a website tweeking thinks from the computer at home (IT can be done) im just not there yet.

I have build a couple of thing just to learn the basic, (there is a bounch of code on the net just keep searching)

1.Min max temp/humidity with a lcd display. cost price about 25$ (enclosure cost was 10$ so could be cheaper).
I have fitted a mason jar lid, with a sensor. So i can keep an eye on my curing proces.

2.On / O timer can handle millisec / seconds / hours / days / weeks e.t.c... cost price about 20$ (enclosure cost was 10$ so could be cheaper).

3. Ph meter with lcd display cost price about 45$

4. ph controller for my hydro res..(only with ph down) cost price about 55$.. (waiting for a new phshield "Dormant Labs PH Module V2"..

5. NEXT project. Automatic watering system for soil(1-10 plant setup - gravity feed). All buckets is watered individuallyWhen dry.
cost price about 100$ (heavy duty solenoid valve 10$ a piece. so could be cheaper)(it´s a custom build for a friend... I don`t do soil).

Theese little arduino things rocks. you can get one for as little as 3.68$.
:Sharing One:

 

[pop22]

I'd like to build a thermostat for a homemade chiller, to turn it on and off by temp. Remote display of res temp would be great also. commercial ones are over $100!

 

[KsjAuto]

I'd like to build a thermostat for a homemade chiller, to turn it on and off by temp. Remote display of res temp would be great also. commercial ones are over $100!

Sounds like a nice project
What you need is something like this.

1.Arduino board 4-10$ Arduino nano ( china clone) is 3.68$ arduino lenoardo is about 9$
2.water proof temp sensor DS18B20 3$
3.Relay to turn on the chiller 1,5 $
4.lcd display 1602 5$
5.Wire and a wall plug $$$$?
6.enclosure 1$
7.Wall adapter 5-9v (usb charger 5v 1,5$)

So your looking at 15 - 20$

The temp sensor sample. code you can find on the web.
The lcd is a little more tricky to get to work. but not impossible.

That should be a nice little project And money to be saved !
:Sharing One:

 

[pop22]

KJS, thank you! I'll be checking out those parts! Want to prep my $30 dehumidifier soon!

 

[captain budseye]

Nice one kjsauto that sounds sick! I study electronic engineering and have been pondering on this for a while, never quite had the time to commit though. From what I've read you have to be careful about trying to adjust the ph using ph up/down as the controller can't track the actual balance of nutrients which I could see going horribly wrong. I know very little about hydro though.

I thought of a good way round this though. if you adjust the ph using ph up/down to a limited capacity and then have a waste reservoir that you can dump the unwanted feed solution into and then have it automatically refilled with the right amount of nutes/water for the stage of growth (tracked by the controller) and voilla! Problem solved. Would be wasteful though and require a lot more space/resources. Also the controller couldn't account for any nutrient burn or deficiencies caused by the unbalanced nute solution. I guess you could have smaller individual reservoirs for each pot in a segmented flood drain system or something like that and have the nutrient solution tracked in real time so that every time it wavered out of balance it was dumped and refreshed. Again I don't know much about hydro but I think the concept could be engineered to be efficient and reliable. What u think?

 

[KsjAuto]

I cant see why to dump anything..
The best way around arduino is to not overthink what your doing,
The way i build the ph controller was like this.
Ph probe in res all time.
Taking messurements every hour.
If ph goes over 6.2 a relay is turned on driving a dosing pump.
Dosing pump is connected to a bottle with tap water ph,ed to 4ish. Dosing pump gives about a drop,when turned on.
After "dosing" another relay is turned on for 15min driving a air pump giving oxy.. To the res. Get the drop from dosing pump mixet with the res. When airpump shuts off. Ph is messured again keeps.looping until ph is 5.6. When desired ph is reached.system go to sleep for an hour and start again
Sorry for the bad english
With another relay and dosing pump. ph up is also possible but i have no need for that at the moment.

When doing hydro you can messure ppm and ec.. With does ppm values you can see if the plant needs more food ore less. So if you have a strong ready made nute solution.the only thing is to hook up a dosing pump. Ec probe and sheild. Well that is what i was thinking.
☺

 

[KsjAuto]

In your perfect scenario. What should your "controller" do? Ph.ec.temp. ??????

 

[captain budseye]

I only plan on growing in soil as I only want to grow for Percy and smoke for taste and relaxation over a strong high, but I am really interested in hydro, but know only the basics. When I get round to it I was just going to build a controller to control temp, humidity, co2, watering and possibly light height.
Sounds like you've got your system figured out though dude . Not trying to be a troll but surely you would have to really understand the strain you're working with because from my understanding they uptake different nutes and trace elements at different rates. If you're only measuring ppm and ec this could lead to an imbalance of the nutes and trace elements in the solution even though the system says everything is ok in terms of concentration, ec and ph, especially if using ph adjusters. Sorry my chemistry is not amazing, does the ec tell the balance of nutes accurately or can some of the metal ions 'trick' the system so to speak? I.e. the ec looks fine but there's a build up of zinc ions and a deficiency of say iron. I also have no idea how long it takes to cause nute burn in hydro systems, but that would worry me too because the controller wouldn't adjust for that.

I agree. With anything computerised controlling hardware, you want the simplest and most elegant solution possible, but not too simple. Especially with something finely balanced, you need to model the nature of the system and control it from a human understanding because the computer will just do as its told! That was were I was coming from with dumping unbalanced nute solution and using smaller secondary resevoirs for each pot. They could still be adjusted to a limited capacity, I'd just worry about the controller over the length of an entire grow or even a month, no? Or am I missing something? Nice one dude.

 

[KsjAuto]

My perfect scenario is this. im growing with recirculation system in hydro

Controller should handle

Ph up (i have not used ph up the last 3 years)
ph down (thats my biggest problem with my current system)
ppm up (dosing from ready made solution. apropiate for the plant)
ppm Down ( delute nute solution with fresh water)
humidity NO control just messuring
Temp NO control just messuring

Webserver To check
ph/ppm/temp/humidity.

Watering is done by another controller.

My res is also dump´d / refilled every 7-8 days,,,,, Les salt build up. I did not fully understand the "unbalenced nute solution"
You can´t messure salt build up with ppm ore ec,, So dumping nute solution is a must.
So there will be manually labour....Tweking the nutes for the plant / making a new res.

Things is fast in hydro, nute burn / defiencies / e.t.c.
Basic ppm in hydro
If ppm goes up (nutes to strong = delute)
if ppm goes down (nute to week = ad more nute)
if ppm is stable (sweet spot plant is happy)

but a have managed to figured out a way to up my ppm and keep my plant slight underfeed the hole grow. I have used my last 4 grows to figure it out.. (simple math )

I can see your point now with dumping nutes and the smaller secondary resevoirs.
But if you growing the same strain (Photo) clones.. a single res should be enough. in theory.
I completely suck. when it comes to growing in soil... ..

I also worry about the controller over time..
Things need to be looked after over time... Probes/sensors e.t.c.
Fail safe should be incorperated in the programming (warning if someting is wrong Sms / email / e.t.c.

But that is the fun part about DIY. Tweeking things to perfection..

Im doing my controller in baby steps.
In that way i can see if things work out over time. Tweeking things as time goes.
And learning as i goes.
Up til now my arduino`s is steady.. no hickups (temp/himidity sensor_-_ On off timer 40 min off 3 min on.
Im not in a horry to finish this project. To much info to take in.

as you can see hydro and soil growers have different needs / problems

btw controlling light height that would be nice.