Remote temperature monitoring - Orchid Board

richardb · #1 02-02-2012, 03:24 PM

Does anyone know of an "affordable" device which will transmit greenhouse temperatures 100 metres to a display inside the home?

Discus · #2 02-03-2012, 03:10 AM

define "affordable"...

I will assume you have power in your greenhouse.

I personally use a server-room grade piece of kit called a Jakarta Interceptor; similar devices exist from other manufacturers. I then use a piece of open source software called Cacti to make graphs, although the interceptor makes it's own. This is described graphing here and gadjet here.

They are not exactly cheap, but being IP based is pretty awesome. You can also set it up to email you if the levels get out of whack (handy). Another option is to pair it with something like Nagios and an SMS gateway if you want SMS notification.

Another variation on that theme is to simply put a webcam in your greenhouse pointing at whatever sensors (thermometer, hygrometer) you happen to have in there.

Assuming you're not into digging a trench, a wireless router or two (or a simple bridge device from the likes of Mikrotik or Ubiquity) and you're set.

One day, when I'm a real grown up, my greenhouse will have network points. If I'm paranoid about lightning, the link back to the house will be fiber. As a bare minimum, I'd probably use an Ethernet Lightning Arrestor.

There are just wireless thermometers around, but I'm not sure how many have the range. Having it IP addressable however, is made of win and awesome.

Ray · #3 02-03-2012, 09:20 AM

The 100 meters is the primary problem. Most of the "long-range" broadcasting sensors get "iffy" about 10% shy of that.

I have a LaCrosse Technology Wireless 915 MHz Temperature Station (WS-9160U-IT) that claims a "330 feet" range. It retails for around $40 (the one I have left is $25, but I'm sure you can find one locally, and not pay the shipping cost.)

Discus · #4 02-03-2012, 10:24 AM

re: the 100m try to make sure you have line-of-sight with whatever you do use - i.e. stick it as close to the house as you can in the greenhouse, and on the closest window to the greenhouse in your house. If it works there, try a wall near that window. If not, go back to the window. Walls and radio waves are often not friends.

goodgollymissmolly · #5 02-03-2012, 12:16 PM

Once again, depends on the definition of cheap. I have the cheapest Sensaphone. About $400. Since it requires a dial tone to call you, you must have a wired phone attached. I was able to get around that by getting a $100 device called an XLink. It supplies the Sensaphone with a dial tone and links via Bluetooth to a cell phone. So a added a $9.95 per month free cell phone to my cell plan.

It calls both me and my wife up to 100 times until we acknowledge an alarm exceeding preset limits that we select. It ignores answers by your voice mail because you have punch in a code to prove you got the message in order to shut down the calls. I can also call the system myself at any time and get the temperatures at 4 points in the greenhouse.

It has worked perfectly for 3 years now. Total investment about $500 and $9.95 a month for the cell phone.

richardb · #6 02-06-2012, 03:42 PM

Thanks everyone.
Ray, I had looked at the La Crosse WS-9160U-IT, but although it has 330 feet it does require "line of sight" which is a problem for me. The video clip on their website states that the 330 feet is depleted by half EVERY time the signal goes through a wall or window. My greenhouses are away on the side of my house which has no windows. The house was built 1860 and the walls are thick solid, so are a real problem.
As for "affordable", that will depend on if I find something which I am convinced will do the job. I have located a device which the sensor costs GB£240 (I need two - one for each greenhouse) and the monitor costs GB£372. That is not affordable!

Richard

Ray · #7 02-06-2012, 04:18 PM

Quote:

Originally Posted by goodgollymissmolly

Once again, depends on the definition of cheap. I have the cheapest Sensaphone. About $400. Since it requires a dial tone to call you, you must have a wired phone attached. I was able to get around that by getting a $100 device called an XLink. It supplies the Sensaphone with a dial tone and links via Bluetooth to a cell phone. So a added a $9.95 per month free cell phone to my cell plan.

It calls both me and my wife up to 100 times until we acknowledge an alarm exceeding preset limits that we select. It ignores answers by your voice mail because you have punch in a code to prove you got the message in order to shut down the calls. I can also call the system myself at any time and get the temperatures at 4 points in the greenhouse.

It has worked perfectly for 3 years now. Total investment about $500 and $9.95 a month for the cell phone.

That's great for an alarm, but not a way to read the temperature remotely.

I did something similar using a Sensaphone in my house, so it can tap into the land line, and a remote temperature sensor (Thermalarm) connected to an RF sending unit (with a 300+ meter range).

goodgollymissmolly · #8 02-06-2012, 04:59 PM

well like I said I can call it anytime and get the temperature. I don't have to wait for an alarm. I also have a wired readout from a temperature monitor which was my first system, but I find the alarm to be most valuable becauseI don't want to sit up all every night reading a readout. Much simpler to go bed and have it call if necessary. Like I said, I can call it if I wish and get 4 temperature readings around the GH and listen to what's going on inside. Can.t say I've heard anything but fans and heaters but what the heck it's a free feature.

Leafmite · #9 02-06-2012, 05:43 PM

Missmolly,
That is really a cool idea. I've never wanted to take any chances with my exotic plants and orchids so they all live inside, crowding us quite a bit, during the winter. That seems like a sure way to avoid freezing or cooking them. Maybe an attached greenhouse will be an option, someday! Thankyou for sharing!

Ray · #10 02-06-2012, 06:13 PM

Quote:

Originally Posted by goodgollymissmolly

well like I said I can call it anytime and get the temperature. I don't have to wait for an alarm. I also have a wired readout from a temperature monitor which was my first system, but I find the alarm to be most valuable becauseI don't want to sit up all every night reading a readout. Much simpler to go bed and have it call if necessary. Like I said, I can call it if I wish and get 4 temperature readings around the GH and listen to what's going on inside. Can.t say I've heard anything but fans and heaters but what the heck it's a free feature.

Got it. Sorry - I wasn't thinking of the unit being in the greenhouse, and forgot about the thermistor they provide.