Snake enclosure controller

Showcase your projects! We love to see what people come up with, so please share your creations here.
Post Reply
richii
Posts: 12
Joined: Tue Nov 01, 2011 10:31 am

Snake enclosure controller

Post by richii » Thu Nov 03, 2011 12:54 am

Still very much in the early days of this one...

My daughter very much loves her reptiles, and we're in the process of building a new home for her diamond python. A pretty important part of said home is the heating and lighting, to keep things at a comfortable temperature and to supply the right amount of UV light.

Most of the gear available is pretty simple on/off: the temperature is too low so turn on a heater, or it's day time, so turn on a UV light. I want something that's can get us a little closer to nature :-)

The plan is to use an Arduino with a temperature sensor to drive the heater. However, I'll be throwing a real time clock into the mix, so I can adjust the temperatures for both day and night, as well as allowing for seasonal shifts. The day/night transitions will be done over a couple of hours, to slowly increase from the night to the day temperature.

To extend, I'm also going to use it to control the lighting, again with gradual transitions between the day and night cycles.

As mentioned, this is very much in the early stages of development. I'm currently prototyping on an Eleven, with an LCD display shield currently showing me the readings from a pair of TMP36 sensors (one for the "warm" end and one for the "cool" end of the enclosure). The readings seem to be fluctuating a lot at the moment, so debugging that before moving forward with the RTC integration, and from there to the mains relays.

User avatar
jonoxer
Freetronics Staff
Freetronics Staff
Posts: 298
Joined: Sat Oct 15, 2011 11:31 am
Location: Melbourne, Australia
Contact:

Re: Snake enclosure controller

Post by jonoxer » Thu Nov 03, 2011 5:30 am

OK, this project gets bonus cool-points just because there's a snake involved! Do you have a blog or pictures anywhere of what you've built so far? Or even just the snake?

It sounds like a project that could be applied with very little modification to things like aquarium control, so if this is documented somewhere it would probably get a lot of interest.
--
Jon

LukeW
Posts: 91
Joined: Tue Nov 01, 2011 10:14 am

Re: Snake enclosure controller

Post by LukeW » Thu Nov 03, 2011 12:44 pm

There is one project I've been interested in making for a while, which is a general-purpose temperature controller or thermostat.

- Using a PID control loop algorithm for precise, accurate, careful maintenance of a set temperature and the ability to quickly but accurately ramp the temperature if the set-point temperature is changed. Not just your simple bang-bang switching algorithm.

- LED or LCD display to display both the set-point temperature and the actual system temperature right now.

- Flexible choice of different kinds of temperature sensors, eg. K-type thermocouple for very high temperature systems.

- Maybe two completely independent PID loops in the one microcontroller, allowing two different temperature zones to be independently controlled or something.

- Control different kinds of output devices, eg. high-current low-voltage DC MOSFET, or a 240VAC power relay.

I imagine that this piece of hardware could have lots of different use cases, for example a snake enclosure, reflow soldering oven controller, coffee roaster, sous vide controller etc.

But I have to stop before I give Jon all my best project ideas ;)

richii
Posts: 12
Joined: Tue Nov 01, 2011 10:31 am

Re: Snake enclosure controller

Post by richii » Fri Nov 04, 2011 12:13 am

jonoxer wrote:OK, this project gets bonus cool-points just because there's a snake involved! Do you have a blog or pictures anywhere of what you've built so far? Or even just the snake?

It sounds like a project that could be applied with very little modification to things like aquarium control, so if this is documented somewhere it would probably get a lot of interest.
--
Jon
Hi Jon,

Not as yet - it's currently a few wires to a breadboard :-) I'll write it up as I get something a little more interesting happening.

As for the snake: Image

richii
Posts: 12
Joined: Tue Nov 01, 2011 10:31 am

Re: Snake enclosure controller

Post by richii » Fri Nov 04, 2011 12:46 am

Hi Luke,
LukeW wrote:There is one project I've been interested in making for a while, which is a general-purpose temperature controller or thermostat.
I'm more than happy to move to a requirements specifying and testing role! I'll be the first to admit I've got not much of a clue what I'm doing (already trying to persuade a sparky friend to take care of all the high voltage bits for me; I'm okay at five volts and low current, but the mains stuff is out of my comfort zone!)
LukeW wrote:- LED or LCD display to display both the set-point temperature and the actual system temperature right now.
A very early pic, before the temperature sensor was even in place, really just to make sure my button reading and display code was functioning:

Image

At the moment I'm looking at temps for the warm and cool end, with the target warm end temp shown in brackets on line one. The "HEAT" text on line two indicates that the heater is on (also shown by the LED wedged into D13). I'll probably end up replacing the 2 x 16 display with something bigger.
LukeW wrote:- Control different kinds of output devices, eg. high-current low-voltage DC MOSFET, or a 240VAC power relay.
The aim is to have two output circuits, one simply switched (for the heater), and one able to be dimmed to allow the lighting to be increased/decreased over time. The temperature ramp would be controlled by gradually increasing the target temperature over time, rather than a signal increase.

One of the other aims would be to use a current or load sensor to detect heater / lighting failures.

Eventually I'd have an ethernet module in there as well, to allow for a better setup interface, as well as alerting. Sending a tweet if something is out of range or broken would be kinda cool :-) Long term plans though.

richii
Posts: 12
Joined: Tue Nov 01, 2011 10:31 am

Re: Snake enclosure controller

Post by richii » Sun Dec 18, 2011 11:41 pm

Just replaced the TMP36 sensor I was using with one of your new temperature modules; much better!

Post Reply