Is this a viable project for an Arduino board?

Projects General Guidance
1

Is this a viable project on an Arduino board? If so, looking for Arduino board recommendation that would fit project and any project code that may already exist.

Project:

Temperature Sensor & Controller using a thermistor and a 12v halogen light

Overview:

Build a controller with two buttons: 1 - Temp Up, 2 - Temp Down, and an LCD Display to show current temperature (based on a thermistor sensing temp) and the desired "Setpoint" temperature". Using a P.I.D. loop algorithm, check the current temperature from the thermistor and turn on a 12v halogen light to warm the environment up to setpoint, or turn it off to allow temperature to drop to setpoint.

Operation:

Once connected to power the LCD should display current temp (based on thermistor) and a default "Setpoint" temperature (i.e. 75F). Then, operator can press the "Temp Up" or "Temp Down" buttons to adjust the "Setpoint" (LCD should reflect change to setpoint temp.) Then, PID loop logic will turn a 12v Halogen light on/off as needed to control the current temperature.

Purpose:

To maintain the temperature in a small container (about 2 cubic foot) in a range of about 80F to 110F degrees for proofing bread starter and dough. Ambient room temperature is typically in the 65F to 75F, so minimal heat is required to increase temp from ambient to target of the 80F to 110F temp setpoint.

Components:

  • Input power supply: 12v DC, mA TBD
  • Arduino controller
  • 12v Halogen bulb and socket
  • Thermistor
  • others... TBD

Anyone have any thoughts if this is a viable project for an Arduino controller and recommendation on board? (Or recommendations on any other aspect of this project.)

2

Anyone have any thoughts if this is a viable project for an Arduino controller and recommendation on board?

Of course this is viable. You can use almost any Arduino board for this. The most convenient is probably the UNO.

A halogen lamp as a heater? Sure it produces mostly heat and just a little light but there are better heating elements than a halogen light.

3

A PID controller is not a trivial first project.

As noted, an actual heating element might be a better choice than using the by product of lamp.

4

Thanks for the input Pylon on the UNO.

Can you give me your thoughts on heating element alternative to a 12v halogen bulb? I need minimal incremental heat, and just figured halogen bulbs are easily found and inexpensive, so I just went there as a first step. Definitely open to other options.

5

As for existing code.... Search for Arduino incubator or Arduino eggs

A lot of folks have used your idea/system for hatching eggs.

6

Thanks Bigred!

I agree, PID controllers are not trivial. However, I have experience here with FPV Flight Controller programming (Betaflight) and the PID controller logic there.

I'm definitely open to heating element recommendations... I just don't have this background.

7

DangerToMyself:
As for existing code.... Search for Arduino incubator or Arduino eggs

A lot of folks have used your idea/system for hatching eggs.

Hello DangerToMyself - Those would be a perfect match for what I'm wanting to do. THANKS!

8

sdamer59:
Hello DangerToMyself - Those would be a perfect match for what I'm wanting to do. THANKS!

Also, there are temperature controllers available that do exactly what you want. I have one on my aquarium that is set to turn on the heater @ 74°F and turn off when water temp reaches 76°F. I think I paid $12 or $15 for it. Has worked great for the last 4 or 5 years. No Arduino required.

EDIT::
This is what I have. Or very similar. I mounted it, a power switch and an outlet inside a project box. Looks good. Works great.

9

There is a nice straightforward piece of PID code in this link.

...R

10

DangerToMyself:
This is what I have. Or very similar. I mounted it, a power switch and an outlet inside a project box. Looks good. Works great.

Ok DangerToMySelf, you just took all my fun away :(. Your link to the Digital Temperature Controller gives me exactly what I need for less than $15. No need to reinvent the wheel.

Thank You, That was perfect!

I now need to come up with a new project. :slight_smile:

11

Robin2:
There is a nice straightforward piece of PID code in this link.

Thanks Robin2 for the link. That was very helpful!

12

Very doable however my concern is the halogen light would be a fire hazard when enclosed. You can make a heater from power resistors in series parallel format and control the max temperature if it faults on. Everything else would be the same and you do not have the inrush problems of the lamp. Also the Halogen lamps has to operate at a high temperature for the Halogen cycle to work, if it does not reach temperature its life is short.
Good Luck & Have Fun!
Gil