HI, I am fairly new here, Ive done a few projects but need some help/guidance on my next one.
I have this rig that uses a 5w 12v mini brush-less water pump to pump cold ice water through a 1/4" copper tube that is in a spiral under my dogs bed to cool him off in the hot summer as he just cant ever seem to get cool even with the AC on. It works ok but it can freeze him out after a while which is better then being hot but I wanted to find a happy medium by shutting the pump off which will in turn keep the ice water cold for longer. So what I aim to do is to control the temp by turning pump on/off according to temp set. I would like to have a display to show the on/off temp and be able to raise or lower the number without having to reprogram it every time as well as displaying the temp the sensor is reading. I was also contemplating using a second Thermistor to check the ice water temp in the tank and alert me when it gets to warm so I can add ice. I don't necessarily need to see the second temp sensor values but it would be cool if it wasn't to much trouble to do so. I suppose that would mean having a 3 line display or a 2 line and just have the bed temp displaying at all times unless the user goes to adjust the threshold and it would flash over to what the set value is.
I am very bad/new at writing code so I don't know how I would tackle all of this or if I am even able to do so, and adding a way to change values without using a computer I am guessing is a whole another ball game. If it comes down to it I will have to just keep using a computer to change the values. I guess Ill see how it goes.
This is the pump But I can always get a different one if it is needed.
Maybe using DS18B20 temp sensors (ones in waterproof housings) or a 3950 NTC Thermistor, it doesn't have to be super accurate.
I haven't quite figured out the monitoring process yet, I thought maybe attaching the sensor to the copper heat ex-changer under the dog bed and once the desired temp reached the pump would shut off and the reverse for when it needs to turn back on. Say I want to keep the bed around 60°F and ice water is 32°F or so, shutting the pump off when it reaches 58 and back on when it reaches 62. Ill have to play with these numbers but this is just a base starting point.
Other parts I will need is a display, uno (or should I use a different version?), 60V 30A N-Channel MOSFET to control pump (I know its overkill) and a power supply.
Perhaps there is an easier way to achieve all of this? All suggestions are gladly welcome!
Is there a display shield with navigation buttons that would work for this?
The DS18B20 is so good to use that the extra accuracy can be forgiven. You can fix it to the copper pipe with a blob of silicon. I use a short sleeve of insulation, but you might not need that, just some tape.
A Uno should be fine and is convenient to use. A Nano is essentially the same, just as convenient for a job like this, and likely to be cheaper.
I love the idea! My sister has a Whippet who suffers in the cold not heat.
Display shield with buttons is not a must have as you could get away with only 2 buttons for this.
Hold both buttons down for program mode, when there you use the same two buttons to adjust the temperature up or down then hold both again to lock it in.
Not good at the programming but you must have a general layout in mind before you can begin to program.
Sit down and write down what you want to have it do from start to finnish (in a flowchart is good).
Eg.
Arduino turns on and does basic test. (Run pump for seconds then fun test display, check no buttons are active and display warning if any faults. Including a current or pressure/flow sensor can detect pump operation).
Retrieve last temerature setting from flash memory.
Check temperature if outside guidelines start pump/if not outside dont start pump go back to checking temerature.
If a button is pressed check buttons to see if both are pressed or if one, which one
Depending on how you want the buttons to work depends on what happens next.
You could say press the Down button then press and hold the Up as well to go to tank temperature set.
Pressing the Up and then press and hold the Down takes you to the bed temperature set.
Or make it easier and add athird button.
Thanks for the reply's, ya i think that display shield should work good. Is there less or more coding using this type of shield?
I really, really suck at writing code. Realizing the amount of time it will take me to fight/hack my way through coding makes me rethink this. I am more of a hardware guy and understand that aspect of the project. I would like to have these features and im sure to most that understand code think its no biggie, my mind just doesn't think in terms of code like it does for someone who does this all the time. I need a like a code cheat/calculator thing where you say "I want you to do this then that" and it writes the codes needed. LOL
forget about your project for now, and work through the examples that come with the IDE.
It could take hours or days to see the light, depending on your past experience.
Experiment with a single device of your project. The DS18B20 could be a good start.
Move to another single devide, like a relay module for the pump, or the LCD.
when you understand all the single elements of your project, then try to combine them.