Reading The Flow Rate of your water cooling loop with an Arduino.

[jnew513]

I had thought about doing a float type device, but it's actually a flexible water bladder, not a rigid tank (sorry for the lack of clarification), so measuring volume just using the height of the liquid would be pretty much impossible/very difficult.

The main issue i'm having with this is getting my arduino to read both flowmeters simultaneously. I can't seem to figure out how to adapt the code in this thread to work with two flowmeters

[SXRguyinMA]

ahhh well that makes sense to do it your way then.

maybe do something similar to my above idea, but use a scale of some sort to move the potentiometer, and calibrate it to the weight of the assembly. weigh it empty and full, and set that at the min/max

as fara s reading both meter at the same time, I have no idea lol

[x88x]

I haven't looked at the code, so I can't offer any help there atm, but I did notice a potential problem with the concept...the monitor you describe would only measure the delta, not the actual capacity. So, unless every time you start it the res is empty, you won't get a valid value. One workaround would be to incorporate some sort of persistent data storage, and just make sure the monitor is on when you initially fill your loop.

[Konrad]

If a float sensor in the bag isn't an option, then perhaps a weight sensor?

[crenn]

To measure 2 flowmeters, you'll need to attach another set of external interrupts on pin 3.

If you wish for more information, I can provide it.

If you wish to do this, you'll either have to have a known amount of water in the bag or have it empty on startup. Will this also be controlling pumps?

[jnew513]

crenn,

The water bladder will be empty upon startup. If you could provide me with some information on how to convert the flowmeter flowrate readings to a volume, or on how to directly convert the flowmeter readings to a volume, that would be great.

The arduino will be controlling a peristaltic pump to inject liquid disinfectant into the water bladder, and it will also be controlling a motor driving an impeller that mixes the water and disinfectant. I have both the pump and the impeller hooked up to a simple relay to go on/off for some amount of time. The pump has a fixed flow, so the the volume of disinfectant added to the water bladder will solely be a function of the time that the pump is on for, so after the pump has been calibrated/tested, I will know how many seconds of the pump being on equals how much volume of disinfectant that is, etc. The motor running the impeller can just run for some pre-defined constant time, since all it is doing is mixing. The volume of disinfectant to be added will be calculated by knowing the required concentration of disinfectant in water, and thus I need to know the total volume of water in the tank.

I hope this was clear let me know if you have any other questions. Thanks

[x88x]

OOC, what's the application for this? I, and I'm guessing most everyone else, have been assuming it was a PC liquid cooling system (thus the assumption that the bladder would be full on start)...but it doesn't sound like it from your explanation.

[jnew513]

Sorry for the lack of clarification throughout---it is not part of a PC cooling system. It is for a university project that I am working on, in which the overall goal is to automate the addition of the correct amount of a disinfectant into water storage bladder for long term storage (like when you fill up a water bottle and let it sit around for a couple days, and it starts too smell is what we're trying to eliminate) and also to indicate how much water is currently in the water bladder

[Oneslowz28]

To read from 2 flow meters at once you would need to attach a second interrupt to another sense pin on the atmega. You will not be able to read them both at the exact same time though. One will have to be offset from the other. As for fluid level, you couldn't use something like a fuel level sending unit? They are fairly cheap... I bet you could find some micro liquid level sending units online somewhere. Or maybe you could use some sort of thermostatic strip that was attached to the outside of the bladder and it could tell the water level by reading the temperature difference at the water line.