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 Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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 Quest for a fully automatized climate
#7965308 - 02/01/08 03:11 PM (8 months, 6 days ago) |
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Card (Velleman K8055 USB experiment card) ~$50
Honeywell integrated circuity relative humidity sensor ~$20
Sensor cable connected to USB board
Breathing test of sensor with some real basic visual basic programming 
Connecting the fan
Fan test to see if we can control outputs.
We sure can!    
Temperature resistor stolen from an old digital thermometer 
And soldered to the back of the USB experiment card
So far everything is running smoothly
colors to indicate threshold levels + extra black box
two relays to trigger fan and humidifier
soon to be a box. hopefully
it's up a running now with a threshold margin of around 10 points.
also adds 10 values and divides by 10 to avoid spikes and give a smoother line.
Significantly less usage of humidifier with this setup.
(23:44:13)-Channel 1 = set on
(23:12:58)-Channel 1 = set off
(23:11:01)-Channel 1 = set on
(22:45:46)-Channel 1 = set off
(22:43:32)-Channel 1 = set on
set on = humidifier on, set off = humidifier off
every graph pixel equals 10 seconds.
*to be continued*
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quest for a fully automatized climate
Edited by Arp (02/16/08 09:28 AM)
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 Civ
Pinning
 
Registered: 10/14/04
Posts: 1,849
Loc: California
Last seen: 24 days, 2 hours
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 Re: aight controller [Re: Arp]
#7968064 - 02/02/08 10:08 AM (8 months, 5 days ago) |
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OMG ARP DON'T DO IT! IMS GONNA HAX IT AND MAKE YOUR CUBES TURN INTO PORTS.
Let us know how it goes
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"...Gal's seem to hate the thought of blending chicken shit in a blender.
So, wash it well afterwards & DON'T tell them..." -Agar
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Re: aight controller [Re: Civ]
#7985608 - 02/06/08 03:54 AM (8 months, 1 day ago) |
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The programming is about done, sorta. Now waiting for my mate to connect the components and stuff, probably on friday
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Re: aight controller [Re: Arp]
#7994988 - 02/08/08 06:16 AM (7 months, 30 days ago) |
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BumP! 
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RogerRabbit
Bans for Pleasure
Registered: 03/26/03
Posts: 17,593
Loc: Pacific Northwest
Last seen: 3 hours, 1 minute
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Re: aight controller [Re: Arp]
#7995036 - 02/08/08 06:46 AM (7 months, 30 days ago) |
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My experience with humidity transducers is they don't function well above 70%. Perhaps you've found a better one. I work as an electrical engineer in a MS data center. We have a lot of moisture sensitive equipment, and even the $2,000 transducers freak out whenever it rains, and in this part of the world, that's a LOT.
RR
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www.mushroomvideos.com
"I wouldn't want to belong to any club that would have me as a member".
Mark Twain, Woody Allen, Groucho Marx, and anyone else who wishes to claim credit for the quote.
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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at room temperature, this one is supposed to be very accurate between 0-100%, and stable over 70%. according to specs.
consumer laws are tight here, and it was bought from a reputable place
so far so good. if a drop would short it out it'll return 0 until evaporation and resume function.
will be keeping the humidity around ~95%, so shouldn't really be a problem
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Re: aight controller [Re: Arp]
#7995389 - 02/08/08 09:20 AM (7 months, 30 days ago) |
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Bump. Now with temperature sensor, and everything's running smoothly
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RogerRabbit
Bans for Pleasure
Registered: 03/26/03
Posts: 17,593
Loc: Pacific Northwest
Last seen: 3 hours, 1 minute
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Re: aight controller [Re: Arp]
#7996284 - 02/08/08 01:31 PM (7 months, 30 days ago) |
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I've thought about wrapping the transducers in tyvek, but haven't got around to trying it yet. If yours get shorted out with droplets, it might be something to try.
RR
--------------------
www.mushroomvideos.com
"I wouldn't want to belong to any club that would have me as a member".
Mark Twain, Woody Allen, Groucho Marx, and anyone else who wishes to claim credit for the quote.
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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was thinkin the same. will know in a month moving to new place 
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poke smot!
cognitive consonance
Registered: 01/08/03
Posts: 4,278
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Re: aight controller [Re: Arp]
#7996590 - 02/08/08 02:54 PM (7 months, 30 days ago) |
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Hey Arp, it's great to see someone else working on this stuff.
I hate to disappoint you but there are cheaper boards to accomplish what you're doing. There's this arduino thing which is a USB enabled microcontroller, it can be had for $28 to $32 and can even run independent of a PC. In the simplest sense it can just be used for the PC to read sensors and read/write IO pins. Check it out-
http://arduino.cc
Anyhow they have various versions including a bluetooth version - a bit more pricey but works great! Here's a box that uses one of them (sorry pic is dark):
Anyhow I recommend you check out sensors by sensirion. The series I have in mind is the SHT71 / 75 or SHT11 / 15. These are really great for high-humidity applications. The sensors do all the calculation & analog-to-digital by themselves. Also, there is a heating element inside the sensor which can be activated by the PC or microcontroller.
An issue with crappy humidity sensors (see: HM1500 by humirel) is that, when in environments above about 80% humidity, condensation can build up inside the sensor causing the reading to be higher than it is. With those old sensors the only way to keep it accurate would be to periodically give it time to dry in a desiccant chamber.
The sensirion sensors' heating element can be activated depending on the surrounding humidity. For example, after each reading it can be activated for 5 seconds, and how often it is activated can be determined by how high the humidity is - the higher it is, the more often it heats, thus the more condensation that evaporates as a result.
With the SHT's you'll find they are reliable & accurate even in sustained high humidity. I've done some pretty thorough testing on this to confirm, as I wanted to use the best sensor possible in my product.
In any event, I've been working on things similar to this since 2003, albeit at an incredibly erratic yet slow pace. If you would like to collaborate at all, that would be great. I can also link the other threads on this forum, about this topic, here in this thread if you would like.
I tried formulating an open source version of this, for something cheap & relatively easy for a hobbyist to assemble. I had forums up and everything, but there was not enough interest in it from anyone but spammers (and oh, was there spam! and endless barrage). Still, I think it would be a good idea. Even if the thing is considered a novelty item by some, it sure is nice to produce pretty graphs and stuff:
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Re: aight controller [Re: poke smot!]
#7999600 - 02/09/08 10:29 AM (7 months, 29 days ago) |
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Thanks for your post 
Hopefully this sensor will work, if not I'm going to purchase one of those with the heating element.
Allthou I rarely had any problems with condensation from humidity ranging around 90-95%, and regular cheap hygrometers seemed to keep up with the wet/dry bulb
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cosmoline
expertcontaminationgrower
Registered: 08/11/07
Posts: 170
Last seen: 3 months, 11 days
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Re: aight controller [Re: Arp]
#7999685 - 02/09/08 11:03 AM (7 months, 29 days ago) |
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I second the arduino. Good job though.
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Buy the ticket, take the ride.
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Quote:
RogerRabbit said:
I've thought about wrapping the transducers in tyvek, but haven't got around to trying it yet. If yours get shorted out with droplets, it might be something to try.
RR
Was thinking that spores might confuse the sensors as well? You think tyvek will keep them out?
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LoWgRoW
Strange
Registered: 09/22/07
Posts: 251
Loc: NYCHITY
Last seen: 1 month, 12 days
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Re: aight controller [Re: Arp]
#8004040 - 02/10/08 10:01 AM (7 months, 28 days ago) |
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good stuff. input input input. share the code!
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Beauty in things exists in the mind which contemplates them.
Your fortune for today...
Avoid negative people.
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Re: aight controller [Re: LoWgRoW]
#8007767 - 02/11/08 06:52 AM (7 months, 27 days ago) |
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sure thing. when it's somewhat finished, and if there's a demand
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desertturtle
Registered: 06/15/07
Posts: 140
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Re: aight controller [Re: Arp]
#8014655 - 02/12/08 07:42 PM (7 months, 25 days ago) |
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Interesting, keep it up!
Blows my mind, 5 for you!
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Quest for a fully automatized climate [Re: Arp]
#8021363 - 02/14/08 08:19 AM (7 months, 24 days ago) |
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*bump* updated! everything works according to plan
Edited by Arp (02/14/08 10:02 AM)
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Arp
roving mycophagist
Registered: 04/20/98
Posts: 2,129
Loc: in a van by the river
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Re: Quest for a fully automatized climate [Re: poke smot!]
#8021746 - 02/14/08 10:11 AM (7 months, 24 days ago) |
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http://www.futurlec.com/Gas_Sensors.shtml
something I thought could be interesting (the co2 sensor)? 
perhaps it won't work with high humidity.
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poke smot!
cognitive consonance
Registered: 01/08/03
Posts: 4,278
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Re: Quest for a fully automatized climate [Re: Arp]
#8021784 - 02/14/08 10:23 AM (7 months, 24 days ago) |
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That co2 sensor is a pain in the ass  I have two.
It requires a really low impedance & high gain as the output range is *supposed* to be between 320mV (low ppm) to 260mV (high ppm), and you'll need a two-stage op amp to bring the voltage range within the normal range of analog-to-digital converters while still retaining some precision.
The problem is, the sensors I received from futurlec don't perform within spec. Both sensors output about 240mV at room PPM. I've contacted futurlec and they assure me this is normal, but unfortunately I haven't had a chance since to tweak my amplifier circuit to reflect the different range.
As for high-humidity, I don't know how well they work in these conditions. I'll have to do some testing once I get the sensors working properly.
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Erik006
MushroomCultivator
Registered: 07/13/03
Posts: 310
Loc: Ontario
Last seen: 3 months, 9 days
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Re: Quest for a fully automatized climate [Re: poke smot!]
#8026715 - 02/15/08 10:54 AM (7 months, 23 days ago) |
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I suggest taking a close look at the data sheet, since it actually has a graph describing the output of the system over a range of humidity levels. The graph seems to go up to about 85%, which indicates that it's probably not very suitable for this sort of application.
Furthermore, since the humidity range from 85% - 100%RH is unknown, you'll have to perform a static calibration of your sensor to find out E0. This means you need another CO2 sensor with known accuracy & bias & precision error to be able to estimate the true C02 value & use that to calibrate your sensor.
Most likely you don't have that kind of equipment lying around, so the best you'll be able extrapolate the curve to estimate what value you *could* be getting. Ofcourse, since the calibration curve shown in the data sheet isn't linear at higher humidity levels, you really don't know what to expect.
Erik006
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At last you know what ineffable is, and what ecstacy means
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