Pneumatics-Code [and piston output length]

[reilly]

What is the output [piston length] of the given piston, in other words, how much does it extend?

Also, does the FRC_default.hex or FRC.hex supply functions for pneumatics,pwm signals for pneum. solenoids?

[Alan Anderson]

Originally Posted by reilly

What is the output [piston length] of the given piston, in other words, how much does it extend?

At the risk of sounding unhelpful, that depends on the length of the piston.

Also, does the FRC_default.hex or FRC.hex supply functions for pneumatics,pwm signals for pneum. solenoids?

You don't control solenoids with pwm signals. You control them with relay signals via a Spike. The default code copies a bunch of joystick buttons to relay outputs. Look at the user_routines.c file and search for the Buttons to Relays section.

[Steve W]

A pistons length is about 2 " longer than the throw when in closed position. Therefore a 4" throw would give a 6" in length piston closed or 10" when open. This is a rule of thumb and not exact. Smaller throws still need minimum 4 "

[Max Lobovsky]

I believe he is asking about how to control how long the piston extends in code. There is no easy way to do this without sensors, feedback, and multiple solenoids per cylinder. If it really is important, search multipositioning with cylinders for some help on the topic.

[Astronouth7303]

Originally Posted by Max Lobovsky

I believe he is asking about how to control how long the piston extends in code. There is no easy way to do this without sensors, feedback, and multiple solenoids per cylinder. If it really is important, search multipositioning with cylinders for some help on the topic.

We did this last year. The key for us was a solenoid that centers when there is no power (Meaning if relay1_fwd == 0 and relay1_rev == 0, no air would move). Otherwise, you can use 2 solenoids: one as a go/no go, the other for direction. See the shoulder_* functions in grabber.c in the 1227 code for an example.

[reilly]

Actually, I was refering to the only given cylinder that came with the kit, the pneumatics manual doesn't give the specs for the given cylinder [not all those you can order].

Is there any difference between throw and stoke?




P.S. Yes I was asking about pwm control: thank you for the coding tip [link].