Looking for help on my new idea (micro-greenhouse)
Dougbrowne
Posts: 21
So I came up with a cool idea to make a "micro-tropical-greenhouse" in my room (Since I live in NY *not tropical*) and decided to use a propeller chip to control the climate inside of it. So far I have the following thought up
-Use a florescent growing light to provide the plant with the energy required for photosynthesis
-Use an incandescent light bulb for heating the air within the enclosure
-Use an old vicks humidifier I found laying around to control the humidity within the enclosure.
-Use an HS1101 to retrieve relative humidity information.
-Use DS1620 digital thermometer to retrieve temperature data.
-Use sensiron to collect relavtive humidity and temperature data.
-Use DS1302 RTC IC to keep time to turn on/off the growing light.
When the relative humidity is below optimal for the plant to grow then the humidifier will be turned on and stay on until humidity is back to optimal reading. When the temp is below optimal for the plant to grow the incandescent light will be turned on and stay on until the correct temp is reached. The growing light will be turned on/off at specific times of day in order to simulate the day/night cycle.
I'm pretty new to electronics in general and have never really worked with relays before. Would these relays be good (https://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/relay/List/0/SortField/4/ProductID/657/Default.aspx) to allow the prop to control the 120VAC items (humidifier, the two light bulbs)?
Any suggestions? Criticism? Commentary?
Thanks!
Post Edited (Dougbrowne) : 3/11/2010 2:16:11 PM GMT
-Use a florescent growing light to provide the plant with the energy required for photosynthesis
-Use an incandescent light bulb for heating the air within the enclosure
-Use an old vicks humidifier I found laying around to control the humidity within the enclosure.
-Use an HS1101 to retrieve relative humidity information.
-Use DS1620 digital thermometer to retrieve temperature data.
-Use sensiron to collect relavtive humidity and temperature data.
-Use DS1302 RTC IC to keep time to turn on/off the growing light.
When the relative humidity is below optimal for the plant to grow then the humidifier will be turned on and stay on until humidity is back to optimal reading. When the temp is below optimal for the plant to grow the incandescent light will be turned on and stay on until the correct temp is reached. The growing light will be turned on/off at specific times of day in order to simulate the day/night cycle.
I'm pretty new to electronics in general and have never really worked with relays before. Would these relays be good (https://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/relay/List/0/SortField/4/ProductID/657/Default.aspx) to allow the prop to control the 120VAC items (humidifier, the two light bulbs)?
Any suggestions? Criticism? Commentary?
Thanks!
Post Edited (Dougbrowne) : 3/11/2010 2:16:11 PM GMT
Comments
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PG
Since the Propeller already has an I2C port for the EEPROM you might as well take advantage of it and use the I2C variants of the thermometer (DS1621) and clock chips (DS1307).
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Jon McPhalen
Hollywood, CA
Usually the problem with a micro-greenhouse like this isn't providing heat, but being sure that you can get RID of the heat generated by the lights.
No matter how efficient your bulbs, you are probably going to have to vent heat out so be sure to provide vents at the top and some sort of a fan. To get enough light
to actually GROW the plants, you need quite a few florescent bulbs or one of the high intensity Discharge lights. ( lots of heat ) Be sure to check out how many
foot-candles the plants you intend to grow actually need. ( also the spectrum can be important ) Most people never provide enough for healthy growth.
The HS1101 is going to run you almost $15.00 and requires 10 volts
The DS1620 six bucks, you're still ahead of the Sensirion, at $35 but you still have to convert the capacitance signal of the HS1101 and talk to the DS1620
If this is a one time thing, the Sensiron might be a much faster, convenient overall solution.
The other thing I would recommend is some dumb fail/safes ( mechanical thermostats ) to backstop the electronics. These environments can be combined with an aquarium
which will provide all the extra humidity you need as well as some handy heat-mass for temperature stability.
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" Anything worth doing... is worth overdoing. "
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In the parallax store, the HS1101 is only a mere $4.99 and runs on 5-10VDC. But still, it would be a bit of an annoyance to have to put a 5v regulator on the board along with the 3.3v one. But at the same time, I'd rather keep the cost as low as possible and don't like spending more then $10 on a component that is going to be permanently affixed through soldering (If I'm not soldering it, at least I can use it for a number of different projects for testing and toying with). As for getting the HS1101 the 5v that it wants, could I just run a line from the 5v reg out into the connection of the sensor (same place where prop pin is connected) with a resistor to compensate from the 3.3 already coming out from the prop? Or?
Not sure exactly what you mean. As long as I turn off the source of heat when the temperature is just right, it won't get any hotter - only colder if anything and if it does, the heating light will simply turn back on.
Post Edited (Dougbrowne) : 3/11/2010 1:14:18 AM GMT
See, running a planet, now matter how small, gets kinda complex. You'll just have to think over how your software will make those kind of decisions.
Yes, that is very true... I was thinking about placing the incandescent in a way that only the heat will dissipate into the green house and not much of the light. So this way if it's too cold at night, I could just have the incandescent on and the full spectrum off. As for when the humidity is too low but it's already too warm.. then.. Hmm. Haven't really thought much about that - I suppose i will implement a fan to dissipate the heat as Ken suggested.
Hmm thinking about just going with the sensiron now, instead of the HS1101 + the digital thermometer.
Also, what material should I use for the enclosure? Glass? Plexiglass? A simple plastic film?
Post Edited (Dougbrowne) : 3/11/2010 2:02:53 AM GMT
So what you do is you vent the heat under your house if it's got a conventional foundation or into the attic otherwise, so the hot air has room to dissipate and mix before becoming visible to the FLIR. Or so I've been advised. Really, I've also been advised that as cool as indoor gardening can be, even if you just want to grow green peppers it's a bad idea this time of millennium because of the law enforcement craziness.
A couple thoughts I had while reading your post:
- Checkout the Programming and Customizing the Propeller book. There is a chapter related to studying HVAC systems for houses. They built a small model and had some ideas on how to heat/cool the model and to build vents that were servo controlled. I imagine your green house could use some similar concepts and ideas from their model home.
- Go with the Sensiron because it is a great sensor, accurate and gives both temp and humidity.
- Certainly review what the lighting requirements are for your plants. I know various plants require various lights. For a while I was following a company that claimed to have good LED growing lights. Be careful though because there are also cheap knock-offs. The company I was following, I can't remember the name, but was in FL and had a university or two use their growing LED lamps in research projects.
- For a more advance project, you could rig up your controller with ethernet and have the controller get the latest weather conditions from some tropical place and then mimic those conditions in your green house. For instance, if you lived in Michigan USA you could have your green house setup to mimic the weather conditions from a city in southern Florida.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com
Wherever you vent to, just consider what will happen to the humidity when it gets there: you don't want condensation occurring somewhere in your building and growing mold along with your iguana. And low cal Roger is right: you don't want to give the Man an excuse for playing cowboy. Sometimes, after they've stepped on your neck in the mud and made a mess of your house, they "find" things stuck to the bottom of their jackboots to justify their hyperactivity. I can't imagine the stress they must be under when they kick down a door, scream through their gas mask "Mggwwuh hmmgghhg hgmm!" and sweep a living room with their over-caffeinated fingers on their testosterone-pumped shot guns. Accidents happen. Do be prudent.
Thanks for those ideas/suggestions, they are really appriciated! I really like the idea of simulating a certain area's climate, the only thing I'm worried about is getting an rj45 magjack onto a per board to interface with an enc(forgot the namme of the chip). I could always just solder leads to the pins and then onto the perfboard, but that's not very pretty. anybody have ideas on how to do this?
The servos are also a good idea to control a vent or two.
I've attached a picture of the bath tub and of the·project ( no enclosure yet ) just so you know it's not weed, it's butter beans.
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1986 Chevy EL Camino·· No prop yet
1984 Suzukie GS1100GK No prop yet
We did this in Ohio all winter and had vegies and a pineapple and numerous tropical plants, bonsai trees. Good luck and keep us posted!
Ken
Sorry about the pot joke -- I live in Los Angeles and "medical marijuana" is everywhere.
For your first prototype you might want to use the Propeller Platform that GadgetGangster.com sells (okay, I designed it for my N&V column, but have no financial stake in G/G sales). It will give you a Propeller board with a beefy 5v supply. Nick has a prototyping board as well -- you could drop your clock, sensor, and other IO on this -- the whole works would git into a package smaller than a PB&J sandwich.
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Jon McPhalen
Hollywood, CA
Haha no problem at all with the joke - I have a sense of humor, not to worry xD
About the propeller platform - Thanks for the suggestion but I'd save more money just doing it from scratch on a perfboard because i already have a lot of the parts needed laying around (DIP Propeller, Caps, EEPROM, vregs, etc) with the exception of a few (I don't think I have an extra xtal or 3.3v reg (I do have 5v) )
And to everybody who has replied, thanks for your feedback and cool project Chip.
Back on topic:
I've decided to go with the sensiron for humid/temp and also would like to implement an Ethernet interface so I can grab some data off the internet with it. Also thinking about putting in a small serial LCD to display status/debug info. Hmm, this is starting to become more expensive than I thought it wow
But anyway, I was just wondering. If I were to use these relays to control the 120VAC devices http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/relay/List/0/SortField/4/ProductID/657/Default.aspx could I just hook them directly up to the I/O pins on the propeller with a resistor (56Ohm?) in series to bring down the prop i/o pin's 3.3V to the specified 1.2V for the relay? So I would simply be able to set a pin output high and the relay would turn the device on?
Post Edited (Dougbrowne) : 3/11/2010 11:25:49 PM GMT
Doug - For a project I recommend planning it out in steps. Sure, there are options to add such as a serial display or Ethernet, but plan for those and add those in once you get the core project moving. ALso you cna plan ahead and then as funds allow add those elements. Regarding the solid state relay, I don't think you need any resistor included in the circuit. I could be wrong though. I would study the data sheet for the part a little further and also take a look at the Digital I/O Kit that Parallax sells that uses this relay. Here is the schematic for that kit: www.parallax.com/Portals/0/Downloads/docs/prod/boards/DigIOBrdSchem.pdf
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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com
The reason why I thought a resistor would be required was because on parallax's website (on the page for the SS Relay) it says "Control Voltage: 1.2V @ 20mA (50mA MAX)". Then when looking at the datasheet where that spec is listed it said 1.2V normal, 1.4V Max. So since the props I/Os run on 3.3V (right?) I would need to bump it would to around 1.2 to not hurt the relay. I could be wrong, I don't have much experience with this stuff
Post Edited (Dougbrowne) : 3/12/2010 12:20:07 AM GMT
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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com
Take a look at electronics surplus houses. I have found some neat solid state relays before, sometimes the specs can be fudged, some even give a proportional AC output depending on the low voltage DC input. Many ideas here.
With command from a Prop, I'm sure this can grow anything, even tomatoes.
- Jesse
Post Edited (Jesse Druehl) : 3/12/2010 6:12:34 AM GMT