Hi there,
I am looking for some HW that would enable me to blow or unblow a ballon via the arduino board. This device must inject or extract a precise amount of air.
If you have any link let me know.
Alex
If you need a precise amount of air, a piston and cylinder sounds like a possibility, or a bellows. In either case, you'd have to drive it with a motor or similar actuator. You could use a car-type tyre pump (12V), but that won't be precise. Maybe use an un-precise pump and a measuring system?
what sort of pressures are you talking about?
look into dive equpment - mainly second stage regulators, they use a diaphragm to maintain pressure in you mouth, if you inhale it magially injects more air so you never have to suck and yet never waste un-breathed air.
They are adjustable to get the pressure just right, I beleive its done by the tension on a spring against the diaphragm, if you could make this adjustable by the arduino you could regulate the pressure in, or out of your balloon.
if you need higher pressures take a look at a "wastegate valve actuator" off a cars turbo - does the same thing just less precisely ( but with higher pressures ).
Interesting.
First, a piston and a cylinder is what I tought first.
As for the how precise, basically I would need not to exceed a certain pressure, so when this pressure is reached it stopped sending air. That is all really.
Alex
Sounds like you need a pressure sensor and a pump, and then control the pressure accordingly.