Accurate water consumption

Hello, I want to accurate give water to my bush in a pot. I want to be very accurate in the water that I will use. I will gather the water from a big bottle and thinking of using Liquid Flow Meter - Plastic 1/2" NPS Threaded + Liquid pump. Will it work? Is there any more accurate solution?

How about monitoring the weight of the water bottle?

PerryBebbington:
How about monitoring the weight of the water bottle?

With a strain gauge?

Don't know, never done it. Just throwing out ideas. I suppose that's what you would use. Maybe even buy some old electronic scales and repurpose the electronics.

How accurate is your liquid flow meter? Actually, I think a peristaltic pump probably has a very consistent flow per revolution, maybe you could use that and skip the flow meter. Just count revolutions...

Ok, in case I use a peristaltic one, how I control it? I use a 3.3 Volt Arduino powered by a 5 Volt power bank. And as I see the peristaltic one needs 12 Volt power supply....what current do they draw?

https://www.ebay.com/itm/12V-DC-Dosing-Pump-Peristaltic-Head-for-Aquarium-Lab-Analytical-Water-Liquid/292620317260?hash=item442187b24c:g:d-wAAOSwVRBb5lY8

I would spend some more time researching peristaltic pumps. How accurate do you need to be?

If you think you can meter correctly with run time only, then your task is simplified.

For the best accuracy you will need to count the turns, either with an added encoder, a built in encoder, or use a stepper motor.

How you drive the motor will depend on what you select. Steppers will take a special driver. With a DC motor of some kind, the Arduino will be configured to control (perhaps with a relay or mosfet) a higher voltage supply which will actually run the motor.

Hi,
What volume of water will you be dispensing at any time?
What level of accuracy are you looking for?

Is this college/university project?

Thanks.. Tom... :slight_smile:

TomGeorge:
Hi,
What volume of water will you be dispensing at any time?
What level of accuracy are you looking for?

Is this college/university project?

Thanks.. Tom... :slight_smile:

Hello, around 250ml/every 2 days... The most accurate it can be...
Just a hobby.

There are low voltage peristaltic pumps available (like https://de.aliexpress.com/item/4000974680479.html)

peristaltic.png

You could also use a boost converter to supply the 12V from the powerbank.

peristaltic.png

alex5678:
Hello, around 250ml/every 2 days... The most accurate it can be...
Just a hobby.

If this is a hobbyist thing, then for me, the fun doesn't start with the accuracy of the water dispensed. It is in having a closed loop system where moisture sensors are the ones determining the quantity of water been dispensed to the pot. The quantity of water your plant will require will vary largely over the seasons unless you want to keep editing your code when the season changes.

Peristaltic and single magnet with a hall sensor.

each revolution will dispense the same amount of water and you can read the revolutions with one pin,

dave-in-nj:
Peristaltic and single magnet with a hall sensor.

each revolution will dispense the same amount of water and you can read the revolutions with one pin,

Do you have a product in mind, in order to study it? Another question... I have a 5Volt power bank in order to supply the Arduino @ 3,3 Volt (I use a step down 5V to 3.3V fixed) If I use a step up 5V to 12V in order to supply the pump, will I have any problem such as short-circuit?

#update1: Can this work with the description I gave above: H-bridge ?
With this motor? peristaltic liquid pump

#update2: The power supply is 5 Volt. Is it correct to use a diode between the 5V to 3.3V and another one between 5V to 12V Volt? If yes what characteristics should the diodes have?

Any idea of the current or wattage required? That H- bridge should work if pump current is in range, just don't run the pump backward. I would go with a separate 12V supply for the pump and buck that down to 3.3V for the Arduino.

Can a power bank with 2 outputs 5V/2.1A each, work? I mean 1 output to drive the step down-DC-to-DC to 3.3 Volt and the other output to drive the step-up-DC-to-DC to 12 Volt?

Hi,
Why do you need a H-Bridge if the pump will always be rotating in the one direction when it is needed. :o :o

Tom.... :slight_smile:

TomGeorge:
Hi,
Why do you need a H-Bridge if the pump will always be rotating in the one direction when it is needed. :o :o

Tom.... :slight_smile:

From the few I know, H-bridge diminishes the inductive currents coming from the DC motor, in order not to destroy the Arduino...

Hi,
Use low side switching with back EMF protection diode across the motor terminals.

I think I see that you are over thinking your project without actually getting and experimenting with some hardware.
You are developing a project that is unique to you, which means you need to try some of the ideas in the real world and work out what is best.

Low side switching in your case would be ideal, as it requires very few extra components and if you are using small pump motors then your worries about "destroying" an Arduino are of little concern.

Tom.. :slight_smile:

alex5678:
From the few I know, H-bridge diminishes the inductive currents coming from the DC motor, in order not to destroy the Arduino...

Yes, but so does a single MOSFET and a diode.