breaths per minute - Transducer Sensor

Projects General Guidance
1

Hi,

I'm looking for some help on counting drops in pressure per minute using a transducer sensor on a air line.

I am getting starting pressure and then monitoring that over a period of a minute to see how many times it drops.
When it drops, I am running a count tally then I will see at the end of the minute how many times the drop has happened.

The problem is, when the pressure drops it may drop for a couple of seconds, this is registering as a few drops in stead of just one as it runs through the minute timer.

Any help would be great.

Thanks

2

Are the drops that you don't want to count in any repeating pattern?, like 3 drops instead of one? If so, could you add a delay to the sensor reading period to remove the false readings?

3

ashtonm:
Hi,

I'm looking for some help on counting drops in pressure per minute using a transducer sensor on a air line.

I am getting starting pressure and then monitoring that over a period of a minute to see how many times it drops.
When it drops, I am running a count tally then I will see at the end of the minute how many times the drop has happened.

The problem is, when the pressure drops it may drop for a couple of seconds, this is registering as a few drops in stead of just one as it runs through the minute timer.

Any help would be great.

Thanks

Total lack of any information in order to give help. Circuit schematic? Sensor data sheet? Code? List of pressure values you are looking at?, etc.

Is there a regulator on the line? How does the air line relate to someone breathing? A block diagram would be helpful.

Paul

4

Hi,
You need to count
When the pressure drops.
NOT
When the pressure level when it HAS dropped.

You need to detect the change in level, not the level.

Have you googled..
measuring breathing arduino

Tom.... :slight_smile:

5

Also look for "state change detection". You count the times it drops below a certain value.
Remember to add hysteresis or you may still get multiple counts - so your state goes low, and you count, when it goes below say 100, but your state goes from low to high when the input goes over 120. This way if it hovers near 100 you count only once.