Wellhouse Thermostat Project

[rmain1972]

@Jakeelectronics,

Here is the picture of my wellhouse thermostat. It's currently on breadboard. I'll order an enclosure + other completing parts next monday. The firmware is based on your Fahrenheit version. The project has three LEDs. One red, to indicate that the DS18B20 is taking a temperature reading, one to indicate that the relay is on, and one for indicating power is applied to the circuit board.

 

[jakeselectronics]

Nice.
So when the temp falls to set set temperature does the relay close?
What does the relay control?

 

[rmain1972]

Yep. Right now it will turn on the relay when the temperature falls to 80.9. When I put it in the wellhouse, I'll set it to 45. The relay controls a 250W heat lamp.

 

[jakeselectronics]

Oh yeah, to keep something warm..
Can the temperature be changed up or down via a pushbutton? Or Will you never need to change it..

 

[rmain1972]

I'll probably not need to change it, but I do have up/down buttons which I have included in the project. I have a five degree window. IE, when it turns on at 80, the relay will turn off at 85. The current version is only 4, because it turns on the relay at 80.9. I'll change it later to 79.9 by decreasing the thermostat setting in software. In other words, turn on the relay when the current temperature is at the thermostat setting minus one. In the program I'm only using whole numbers when comparing current temperature. and the thermostat setting.

 

[rmain1972]

Project Update

I have the firmware completed and tested on breadboard. I'm now at the point where I can build it on a protoboard. I'm going to order a ribbon cable and another LCD so that I don't have to take apart the completed breadboard circuit.

I have bought an enclosure (DigiKey SR153-WA-ND). I need to cut out holes for the LCD and other parts. I'm thinking of buying this saw set from Micro-Mark to help cut out the rectangle for the LCD. Does anyone have any tips for cutting out the rectangle. I have cut out a rectangle for an electrical outlet on another enclosure which came out a little rough, that's why I'm thinking this saw set would work better than what I used last time (a 7" handsaw).

 

[jakeselectronics]

Personally I would just use a transparent box, or a box with a transparent lid so the LCD can be seen straight through it.
Then just drill circular hole for your buttons And connectors.