Arduino Incubator "Project"

[Th0r]

PICTURES ADDED - not great pictures - but pictures none the less - -So I don't have any pictures of my actual incubator at the moment but I am currently running a test run with some eggs from a friend.

I thought some of you might be interested in the data collected over the first 23 hours.

I have only shown the graph for temperature vs time. I also have humidity information which is interesting regarding the temperature it is almost exactly inverse to the temperature graph. I realized humidity would go down as temp went up but the correlation surprised me.

Anyway here is the temp graph.



A bit about the project:

It uses 3 DHT22 temperature / humidity sensors. It takes the Median temperature of the 3 sensors. (all are within 0.4 deg of each other) I decided that would be the most accurate and safest way to get the correct temperature, if one sensor fails the median will still be accurate. (Average on the other hand would not be accurate if a senor failed)

The temperature controlled relay is set to turn on / off at 37.5 deg C

So far it is an arduino uno with a sd card shield and a 4 relay shield.

I had a lot more planned for it but ran out of time before spring.
It currently looks a little like a spaghetti monster, but seems to be stable.

Future additions:
Audible alarm for out of temp.
Some method to add humidity based on humidity sensors.
Buttons to adjust target temperature.
Better enclosure and a plug for the sensors so they are not hardwired.

I will try to add pictures in the not too distant future.

 

[Th0r]

I warned that it was a spaghetti monster.

 

[PaulM2]

I'd be interested to know what all you are running via the Arduino, and specifications of your setup. How are you changing the humidity from what you monitor? I think temperature is easier to keep constant than humidity so I am interested in what you have done.

 

[gpop1]

"Average on the other hand would not be accurate if a senor failed"

most library's include a isnan feature (isnan = is not a number) so with a little coding you can easily change the calculation used to average the temp by removing the isnan


if (isnan(humidity_one) || isnan(temp_one)) {
badReadingDht1 = 1;
} else {
badReadingDht1 = 0;
}


"Some method to add humidity based on humidity sensors."

there's lots of different ways like a water fogger that's put in a bowl of water and makes fog when it is turned on. On one of my designs I built a small chamber with water in the bottom then turned on a fan to blow air over the water to increase the humidity. If I had the space I would have liked to have tried the fogger as lots of people on here report that they work well

"Buttons to adjust target temperature."

I did that and in 2 years I've never changed the temperature

"Audible alarm for out of temp."

lol go large and have it text our phone.

great write up and I found your graph interesting.

 

[Th0r]

Right Now I don't have a humidity "injector" setup- the code to control the humidity is inactive in the arduino code. But the plan was to have something either pump water into the bottom of the incubator or inject humidity with something like a small humidifier and some tubing. Either would be turned on or off with the second outlet controlled by the arduino.



I don't really like the idea of pumping water into the incubator automatically- just in case the humidity does not rise enough to shut the pump off and the water keeps pumping and spilling out of the incubator.

If I had more room in the incubator I would use something like this.


Right now i am just manually adjusting by adding water depending on the readings the DHT22 sensors are reading.

Currently only the heater element is run by the arduino, through one of the 4 relays on the shield. the second white outlet that is not being used is controlled separately by the humidity level. the other two outlets have constant power - powering the arduino the fan and the egg turner.

I am a little leery of sensors giving bad values. So I wanted built in redundancy and the median seemed a good way of doing it.

My coop has a auto door controlled by the light level. I went through a half dozen of the photo resistors - they kept failing across the track on the sensor and the values would slowly degrade. At some point I would check the webcam and the door would either be open or closed when it wasn't supposed to be. Easily solved this by using the solar cell from a garden light to send a voltage to the arduino. When it is light out it sends a voltage when it is dark no volts. haven't touched it in almost a year and it has worked flawlessly.

Hopefully Version2.0 will have humidity control a nicer display and a better control enclosure to keep all the wires tidy.

If I had more free time version 2.0 would already be here but alas we are still at v.03