$10 smart grow system using an old computer!!!

i've been looking into a way to control my entire growroom using an old computer, i've seen many ways using a board to build a timer with chips, then i got to some info about a $10 smart home system it is already being used by DIY geeks out there to control their home using their computers. the way it is done is using the old parralel port on your computer and a couple of resistors a transistor a diode an old 6V cell charger and some software. one parralel port allows you to control 8 seperate power outlets each at different time and you can time your cycles to the second. 2 parallel ports will give you 16 outlets this is more than enough to fully automate a growroom! well these are some links, check it out!
hxxp://www.instructables.com/id/SKXE9UHFP8NLL9J/
hxxp://www.epanorama.net/circuits/parallel_output.html
i still didn't buy any parts because i never hooked any electronic parts together so i need some help on this, it seems a simple 3 steps, it would be of great help and benefit to have someone who worked with such parts and could help me make it work, thanks in advance for any input

I wouldn't know how to do it, but that sounds like a cool idea to me. Good luck.

I'm waiting on my development board and programmer to arrive (Santa doesn't do early delivery apparently ) and as one of my first major project I will be developing a modular garden control system using Atmel AVR microcontrollers (basically a mini computer). I have a decent enough grasp on the electronics so what is it you need help with specifically?

Oh so I was puttering in the garage last night working on some mame arcade cabinets I'm making for my brothers for xmas and thought of something I should post here. If you want to do this with a computer and not a microcontroller make sure you get a computer with a real printer port, the old school ones. Best place to find one is in your local electronics recycling depot at night when everyone is gone, unless they allow scavenging. Its where I got two computers two monitors and speakers and cables etc for my arcade cabinets (they have to be made out of recycled stuff long story). It doesn't need to be powerful, an old pII 450 would work fine or something similar, you should be able to find an old CRT and stuff for it to, since the LCD market took off tube tvs and monitors are a dime a dozen.

Good luck let me know if you start this as I would love to help out if I could.

so let me get this one straight, you're gona build the whole controller with a display screen and all? do you have a thread for your project? that would be crazy hard to do i was thinking i need an old computer i have a couple of old ones still laying around the house, what i need is someone to look at the links and tell me how i could apply it exactly, they say i should connect the diode resistors transistor in a circuit but i never did anything similar i wana know just how it's done how these are connected it looks very simple i'm sure anyone with a little experience with these things will find it a piece of cake but i don't know what i'm really reading when it comes to electronic circuits. thanks for your input tater cheers

hxxp://www.electronicstheory.com/

Theres a free course to explain the basics to you, its actually where I started my electronics hobby. Great site and one of the best tutorials for explaining stuff in plain english.

And yeah thats the plan, I want each piece to be modular so that you can plug and play. So say you need a light timer, an exhast control, a pump controller, a ph and TDS monitor. Each piece would be seperate and plug into the main "brain". I would like to make the light controller the main piece because it will be needed in every case. Also this way I can break the project up into parts to help save my sanity.

And don't worry I'll post a thread when I have something done or at least prototyped on a breadboard. But don't expect to see it till summer of 10 because the pipeline season is about to kick into full gear here and I got bills to pay haha.

ZEM,

Now I understand what you are doing --using the computer to control light duty relays. It looks like it would work to me. I will have to read the links carefully to really make any serious recommendations, BUT after having just skimmed them, I will bet you that you will need another layer of relays to actually control your equipment.

I say this because I think you will find that most of those little 6 volt relays will NOT handle the power you are going to be switching. I think what you will have to do is to use the relay in the circuit to switch the low amperage 120V control circuit in Growdude's timer controlled relay set up. Essentualy what I think you will be doing is running the power leg of the 120V control circuit to one of the unlabeled terminals on the relay then the other terminal will run to one of the control circuits on the 120V relay control circuit and the ground leg will just run directly to the other control terminal.

Let me do some reading, but that is my initial impression. Also, I'm not real impressed with the diagrams -- they seem to be needlessly hard to read for the uninitiated. I'm above average in being able to decipher diagrams and they look confusing to me for such simple circuits; OR the circuits are more complex than they look.

Either way, I'm sure they are doable so long as you can locate the proper parts. It seems like number specific electronics parts are harder to come by than they were a few years a go.

Give me a few days to review the literature and I'll let you know what I find out. The control circuit seems fairly straight forward with a little study.

What kind of electrical/electronics skills do you have? Can you do fine soldering without overheating the component that you are soldering? That will be the largest challenge.

Good smoking.

DonJones said:

What kind of electrical/electronics skills do you have? Can you do fine soldering without overheating the component that you are soldering? That will be the largest challenge.

Good smoking.

Click to expand...

well Don ive worked with electrical wiring hooked relays for 24v timer to work my 240v pump hooked breakers switches even hooked an APS backup to my power box at my home but thats only electrical, i never worked with electronic boards i did inspect the board on my timer like 3 times and saw the guy who fixed it remove some micro batteries that needed to be replaced and then he soldered new ones back, i have the soldering equipment and i think with proper instructions i could easily solder without burning parts, i am quite handy and i read and learn before acting especially with electricity.
i think that the drawings of circuits are not very clear because theyr very simple to do, i'll look for more better links, basically i need to work a relay via the parallel port data pins there are 8 pins on each and they give out a very low voltage the thing i dont understand is how to make a proper circuit from the data pin to the main 240v circuit so that i can power several amps, it seems something very simple just need some knowledge on what resistors transistors diodes and circuit components are and how to hook them exactly. i have more than 1 old computer with the old parallel ports would be great to be able to use one to fully automate my growroom, i still need to take few measures after i get the circuit done, i will need to format my old pc maybe romove useless things on it even add some things to make it more durable this is the next step before i can put it to work, computers eventually break and will need fixing i think with some instructions i can upgrade an old pc to work long years 24/7 without breaking.
thank you for being interested in such a project, i am very interested in it indeed, if this works well i think a DIY simplified step by step instructions on how to work growroom with computer via parallel port would become very useful to many growers, i think Tater's future project on building his whole controller on a board would be the best to do but this old PC project is very simple and can be very easy to do for many many people with an old PC layin around i'll be looking forward to hear some input from you, cheers

Zem,

What I think you are going to wind up doing is making a control box, or maybe even more than one that you run the parallel port cable into, mount 8 circuits in it with each one of them controlling one of the 6 VDC relays. Then you will run 120V into the box also with both the ground and power legs terminating in a buss strip, one for each leg (a buss strip, aka terminal strip, is a series of terminals all connected together by a piece of metal so that they provide several places to connect a wire all to a single wire). From the power buss you would connect to one output terminal of each of the 6VDC relays. Then you would connect the power leg on an extension cord/cable to the other output terminal of each 6VDC relay and the ground leg of each cord/cable to the ground buss. The other end of each cord would hook to the control circuit of one of 8 120VAC 2 pole relays which would in turn switch both legs of a single 240VAC circuit off or on.

The way I think it would work after being connected up properly is, each circuit is separate from the parallel port on the computer all the way through. When a particular parallel circuit is turned on a low powered signal turns the 6VDC relay for that circuit on. Then the 6VDC relay turns on the 120VAC relay, which then turns that individual 120VAC circuit on and provides 240VAC power to your controlled equipment.

I'll try to see if I can sketch an understandable diagram and post it to make it easier to follow the explanation, but given my limited drawing ability, that may be hard for me to do.

Good smoking.

Don is right on with this.
Its going to take min 15 amp relays that will be controlled by the control (6 vdc) relays.

It seems the real challenge is going to be the software and drivers needed to control the port.

He does not give you example's of how this is done, the other link does but your going to need to be able to do some programing in VB or C+ to be able to do it.

can i overclock to speed up flowering and make my buds more potent ? lol...

now i know who my fellow pot geeks are lol...

:holysheep: Don i can almost sketch it myself reading your post, but where are the resistors, capacitor, diode?? you didnt mention them, are they a part of the relay? it will be very simple the way you put it but i thought theres something more to it.
growdude i can get some software from the internet specifically for this i wouldnt have to program it

zem said:

growdude i can get some software from the internet specifically for this i wouldnt have to program it

Click to expand...

I would like to see it, is there anyway you can share this info/link?

Industrial automation is my profession, all done with micro controllers or PLC's (programmable logic controller's) .

While one would never need or want to use PLC's for something as basic as grow room automation there is a wide variety of micro controllers that are very cheap you can get a basic I/O 12/in 8 out for about $200.00

These units are programmable from either there keypads or via laptop and software.

One thing you must keep in mind, any control either micro controller or this home built one will require relays capable of handling the loads put upon them.

Also I see no analog input capability to the system, to completely automate one needs to be able to input analog data (temps, ph, Co2 levels) ect.


Automating a grow room is something ive thought about for sometime now.

Zem,

If you consider the "circuit as a little black box" and the high current high voltage relays as another "set of little black boxes" then the circuitry becomes a lot simpler.

Give me a day or so and I'll get back to you. We have total chaos here this morning.

Good smoking.

Zem,

That was simpler than I thought. Here is the schematic for connecting the 3 components of your computer controlled power supply.

I only showed one set to control one 240V circuit, but each of the other 7 are identical but you will probably make one large box to contain all 8 of the "CIRCUITS" and the outlets for each of the 8 different "CIRCUITS".

Here is the way I envision it operating:

The computer sends an ON signal through the parallel cable to the signal inputs of the "CIRCUIT". That in turn energizes the internal relay with connects the incoming line terminal and the outgoing line terminals. At this point we have a 120 VAC signal/power source turned on. Since that 120 VAC output terminal is connected to one of the signal terminals in the 120 VAC controlled 240 VAC switching relay and the other signal terminal is connected to the neutral leg of the 120 VAC source, that causes the 2 pole relay to engage which connects the L1 input and outlet terminals along with the the L2 input and outlet terminals and we now have 240 VAC power in as high of a power rating as the source will supply and the 240 VAC relay will carry safely.

When the computer quits sending the ON signal, the "CIRCUIT" turns off which interrupts the line leg of the 120 VAC signal which turns the 240 VAC relay of and we now have NO output 240 VAC available.

In this scenario, all the "CIRCUIT" is doing is converting a very very low powered DC signal to a higher powered AC signal which in turn controls the main power relay. This intermediate control "CIRCUIT" is necessary simply because the computer signal is NOT powerful enough to control the 240 VAC high powered relay.

The output terminals in the drawing of the "CIRCUIT" on the Internet shows a dual state relay in which there are 3 output terminals only 2 of which are connected at any time --the center one is where the "HOT" switched powerwire is connected and the top one is where the "ON" power outlet wire is hooked. We leave the third terminal empty so we have a simple ON-OFF switching relay.

However if we connect the 3rd terminal to a second device, we now have a toggle either-or switching relay that lets us send power to one of two circuits depending upon whether we have an "ON" signal to the input connections or not. The only draw back about using that set up is you can only energize one of the two devices at a time and when the computer signal is interrupted for any reason the power to the bottom terminal is automatically turned "ON" by default.


Is that pretty much the way you think it is supposed to work? What about you, Growdude, did I miss anything?

ZEM, Growdude is correct, without some way for the computer to sense and respond to the conditions, all you have now is a single source programmable 8 circuits high tech timer. As it is even with sensors, you are still limited to controlling 8 circuits per parallel port/cable. Even wired in the either-or toggle configuration you are still only controlling 8 circuits but 16 devices.

I'll think about how many different conditions we need to monitor and how many output circuits we need in order to control those conditions later.

Good smoking.

View attachment schematic fo rcomputer controlled power supply0001.pdf

Don, first of all thanks again for thinkin this out with me well i was thinking through your sketch and i still don't see it working since if i got you right i'll be switching a 120V power ON which itself powers the 220v ON but this will require me to get a 3rd circuit into this and my electricity voltage is 240 so i would have to get a 240/120 adapter and another line for the 220 and a third for the 6v, it is feasible but it will add to the complication and cost with no need since what i must need with this is supposedly only a 6v power supply and a 240 current. it doesnt require 120v to power 220v, my timer in my current grow is 24v and powers a 240V current with only one single 24v/240v relay. the ones i read about all mention resistors capasitors diode etc... your way is only simply relays one afer the other with 3 seperate surrents, i still believe we are missing something, its supposed to be 2 currents a 6v and 240v between them a circuit of cappacitor resistance diode etc... the normally on outlets on the relays i will not use with any pumps or dangerous things that can mess up if kept on, i might even not use them at all. i counted the number of seperate currents i have to control to be able to automate my growroom and it is less than 16 i'll think it through again tomorro anyway im very tired just got back now gona make a new thread bout totally different subject with a Q about a ppm meter then im gona sleeeeep and yeah i can almost fully automate it im not going to buy a meter with abilities to send info to comp since it is VERY expensive as i saw so i will make a big main res to control my control res this will refill it whenevr needed with fresh nutes already prepared and ready to feed the plants, i will still have to do something like checking the PH/EC but it will make it almost fully automated i'll look for the software later saw it somewhere i'll be back by tomorro thx guys cheers

ZEM,

I'm too ripped to understand your post, much less give you an undeerstandable reply so I respond later.

Good smoking every one

em,

You are missing the point of the "CIRCUIT" 6V power supply entirely. It is there to provide the extra current necessary to close and hold the 6V relay because the output of the parallel cable is designed to be a signal source NOT a power source.

Also the "CIRCUIT" is simply a switch -- not a power source. There is NO power fed to the output terminals on the relay. You have to get power from somewhere to hold your 240V double pole high powered relay.

I chose to use 120V because I can get the power relays for it cheaply and 120V is easy to get if you already have 240V available. just run a circuit from one line leg through the relay switch and then through the holding coil of the 240v relay and back to the white neutral leg of the original 240 V circuit. If you already have 24V available and can find the 24V powered 240 volt high current relay, then you can use 24V to run through the switch built into the 6V relay inside the "CIRCUIT" and on through the holding coil in your big high powered 240V relay.

Does that make more sense?

Good Smoking.