Hi all,
I have an arduino uno starter kit and had a good play a while back with a few tutorial code examples.
I have an problem I think I might be able solve with the right sensor and a tiny bit of code. Basically I need to close a contact for 30 seconds if absolute vacuum gets below 50mbar.
After a bit of reading I think I need a differential vacuum sensor but I'm struggling to work out which - one of the 2 feeds will be open to the atmosphere and the other to the vacuum source.
given atmospheric pressure can vary +/- 25mbar is there any way of achieving this?
Welcome to the Arduino forum. I am sure you can make this work with the experience you have with the kit.
Some things you need to refine are:
accuracy of the vacuum sensor,
speed of the air pressure reduction
speed of return to standard air pressure
speed of vacuum forming.
How often will the vacuum limit change? In other words, will the limit vacuum fluctuate about the limit.
I have no experience with vacuum sensors, so cannot help search one out for you. There may be sensors that just close a microswitch when the limit if reached. Then the Arduino just needs to discover this and do the timing.
Paul
Have You checked bariometric sensors? They are designed for "normal" air preasure but what range do they have? I can't tell but an 280 sensor is waiting to be tested and used.
Q6zwvFSz:
given atmospheric pressure can vary +/- 25mbar is there any way of achieving this?
Yes, you need to choose a pressure sensor that measures absolute pressure and not guage pressure.
Such a sensor will only have a single port.