DIY - Thermometer

[Skitzmixer]

I remember reading a while back about someone who was building their own thermometer / thermostat. Does anyone know how that project went?

I'm thinking about starting my own similar project. My plan was to use a credit card sized computer known as the “Raspberry Pi” and attach a GPIO board to read / control the thermometer. This also allows me to hook up quite a number of thermometers (for multiple readings of the same enclosure or multiple enclosures). I’ve done some research and I can get a thermometer (eBay - DHT22) that does humidity as well. Humidity range is 0-100%RH (accuracy: ±2%RH) and the temperature range is -40 to 80℃ (accuracy: ±0.5℃). So in theory I could get a reasonably accurate temperature.

Because Pi runs on linux it means that I can install other applications such as apache (HTTP web server) to output the readings to a webpage and have some pretty graphs for the day – gives average, highest, coolest etc. I could create email alerts for say if the temperature is over X send a panic alert. Pi connects to the network either through cable or wireless. Once thats up and running i could then forward some ports out to the internet and make the webpage available to view anywhere in the world.

Would anyone be interested in having something like this? I’m trying to get my hands on all the parts I need but I’m fairly confident I can get this working. What would some other features that you’d like to see?

Its only early stages but for me personally it'd save me a lot of stress if i can just jump on the web and double check the temps of all my enclosures.

 

[mad_at_arms]

It was Saximus that had the project
http://www.aussiepythons.com/forum/general-reptile-discussion-42/buy-179799/

 

[Skitzmixer]

sweet, thanks. I'll have a chat to him see how its going.

 

[Zeusy]

I built my own also using a controller we use at my work which has fully programmable ins and outs. I have 3 sensors and use the one on my heatmat to control a digital output which runs a 4PDT relay that turns my heatmat on and off at an adjustable temperature. I also used the time in it to control another relay to turn the light on at 6am and off at 6pm.
My controller also has a pwm output which i plan to connect to a solid state relay so i can control the heat using a built in PID controller to control how "on" the heatmat is. I also have an output for an over temp buzzer and a shut off relay which will use the normally closed contacts through to the heatmat relay supply and when turned on, cuts the supply to the heatmat relay, should the contact short on or something.
It' been fun programming it and testing etc and has worked really well. I use a 2 degree swing on the heat mat which turns it on for about an hr and off for 45 min approx so i think ill drop it to 1 degree.

I quite like the sound of that Pi computer. Keep me up to date with the project if it goes ahead. I'd find it quite interesting

 

[solar 17]

Which Humidity range does this setup give results in ? solar 17

 

[ronhalling]

I suppose if you are going to go to all the trouble and expense of building such an extravegant controller you may as well incorperate multiple lipstick cams to all your enclosures so you can also check on your snakes/lizards well being remotely from any location that has web access....................................Ron

 

[duckhead]

What Ron said... But Yeh if you could make this setup affordable then I don't see why people wouldn't want it.

 

[solar 17]

Which Humidity range does this setup give results in ? solar 17

 

[Zeusy]

mine would work underwater. The OP mentioned 0-100% (+-2%) for the humidity sensor. I imagine that the temp sensors would work in that too.

 

[Shaggz]

All sounds very interesting, Not sure if Ron was a bit tongue in cheek when he mentioned adding cams but that was exactly what I was thinking. I am not up with any of this technical mumbo jumbo but it does sound a little expensive lol

How many inputs and outputs would you be able to control with such a setup??????? I am in the process of building a Reptile room and plan on having roughly 20 enclosures aswell as hatchie racks and incubator so obviously that adds up to a hell of a lot of thermostats and thermometers which obviously isn't going to cheap either. I suppose though running everything on one controller means that if it malfunctions the whole room malfunctions rather than just an individual enclosure. Obviously there are going to be a few pros and cons to work through but I will be very interested to see how far this project goes.

 

[Illium]

Iv considered something similar.
For me it was more as a monitoring system i could use that is web based, a few times a year i travel for a few weeks at time with the wife and kids. While i can get someone to look after the herps for feeding i didn't trust the care factor. (i went away for 2 weeks and didn't get told my filter and pump on the turtle tank failed the day after i left, shell problems occurred.) So im going to look onto the ability to if not change temp setting then at least shut off the the power to each enclosure, and just for visual checks also.

 

[Skitzmixer]

Which Humidity range does this setup give results in ? solar 17

Humidity range is 0-100% (accuracy: -+2%) the model number is DHT22, different ones are available as well, there’s a cheaper option but it’s not as accurate.

Thanks for all the input everyone.

I'll be trying my best to keep it under $100. With the ability to add as many thermometers as you'd like. The cost of the thermometer its self is $5, the pi is the most expensive thing at $55. If you needed more than 10 thermometers then an additional board would need to be added. I could have varying lengths of thermometer cable to suit most situations.

Funny you should say that about a cam, pi has a 2x USB input so in theory you could plug a web cam straight into it and have it display on the web as well. If you wanted to put more in, get a powered USB hub and off you go (i found a powered USB hub that supports 20 connections.)

I'd like to try and incorporate a thermostat feature but firstly I’ll get my feet on the ground by just creating the thermometer and see how much it all starts to cost. If it starts to get too pricey then I can see the project failing, I’m going with if I wouldn’t pay that much for it, then neither would anyone else.

Thanks again.

 

[ronhalling]

Nah Shaggs, was not tongue in cheek, i thought that if the costs could be kept low enough web cams or lipstick cams could be incorperated, especially for some of the high maintenance projects, so if you did have to go away and trust someone to look after things at least you would still be able to check in on things remotely, i have seen remote pi systems used in some greenhouse tomato and strawberry setups where the person in charge can not only view what is happening in the greenhouses but be able to remotely change settings for heat water flow and air flow remotely from his/her home, i know when i have to be hospitalised for a couple of weeks every year i would like to be able to check up on my reps instead of always having in the back of my mind "are they really being looked after like i want"...................Ron

 

[Marzzy]

Use Arduino = D

 

[Skitzmixer]

Nah Shaggs, was not tongue in cheek, i thought that if the costs could be kept low enough web cams or lipstick cams could be incorperated, especially for some of the high maintenance projects, so if you did have to go away and trust someone to look after things at least you would still be able to check in on things remotely, i have seen remote pi systems used in some greenhouse tomato and strawberry setups where the person in charge can not only view what is happening in the greenhouses but be able to remotely change settings for heat water flow and air flow remotely from his/her home, i know when i have to be hospitalised for a couple of weeks every year i would like to be able to check up on my reps instead of always having in the back of my mind "are they really being looked after like i want"...................Ron

Ron, I actually think its a great idea and its something i'll certainly look at implementing (shattered i didnt think about it first though!) I'll make sure to keep you updated.

Use Arduino = D

Oh nice, what books that from? Shame its pretty pricey for the sensor though. I think running 10 of those from the one board would become well out of most people price ranges. Maybe theres a cheaper option?

 

[Marzzy]

( Its the Jaycar 2012 Catalogue )
You can get normal sensors that do Temp and Humidly I just liked the fact they were IR.

 

[Skitzmixer]

( Its the Jaycar 2012 Catalogue )
You can get normal sensors that do Temp and Humidly I just liked the fact they were IR.

I could always add an option for a different style of sensor. Everythings been ordered now so hopefully i should have a working model soon.

 

[andynic07]

I suppose if you are going to go to all the trouble and expense of building such an extravegant controller you may as well incorperate multiple lipstick cams to all your enclosures so you can also check on your snakes/lizards well being remotely from any location that has web access....................................Ron

My mate has his home security system cameras accessible via the web. He looks around his house from anywhere via his smartphone.

 

[Skitzmixer]

My mate has his home security system cameras accessible via the web. He looks around his house from anywhere via his smartphone.

Its not really that hard to do, its just a matter of finding the right program that will run on pi easy enough. Give it some time, once everything rocks up i'll find a solution

 

[steampunk]

I've been looking at using my pi for a humidity controller for my frogs, just something simple like when the humidity drops to a certain level the pi turns the fogger on. But to be honest I have no idea where to start.

I'll be following this thread closely