@reflexlab said in OpenResearch : Pressure Sensor for DuetWifi:
@bearer
Ok sorry, I wasn't aware of linear encoder for pneumatics.
I think your right, it's a great idea I will try to learn about step/dir interface 👍 .
I just want to point out something :
Today I am able to regulate the pressure of my pneumatic circuit for each syringe by controlling 2 supplementary Axis. (U and V)
By controlling the motors I am turning the knob on this type of pressure regulator : alt text
Thus changing the pressure.
So if I understood well, I have two/three options then :
Option 1 (Yours): Use the step/dir interface from the duet to know the position of the piston with a linear encoder and communicate from the duet to an Arduino circuit in order to regulate the pressure thus monitoring the piston position. (Have a PID loop with pressure output / Position input)
Option 2 (Mine) : Use an external Arduino circuit in order to read the pressure of each syringe and communicate to the Duetboard in order to control my U & V axis thus changing pressure.
Option 2 (Mix) : Use the duet to know the position of the piston with a linear encoder, read the pressure with an external Arduino circuit and use those 2 informations in order to control my U&V axis position on the duet to regulate pressure and thus piston position.
Why not use a stepper motor to control that valve and home it by stalling it at the fully closed position. Then you can use the stepper motor to open it any number of turns that you want. No need for a linear encoder.