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Is PSCU Busy? — Parallax Forums

Is PSCU Busy?

bhaskarghsh4bhaskarghsh4 Posts: 20
edited 2013-12-30 16:25 in BASIC Stamp
hello every one :smile:

Without any formality I am going straight to my question. I am sorry for that.

The question is :

Is there any instruction to check whether the propeller servo controller (USB) is busy in driving any servo or not.

And if there is any material from where I can know the detail working of PSCU then please provide info about that.

Thanks.

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2013-12-30 07:55
    The information for the Propeller Servo Controller is here and here. The firmware source (2nd link) has comments in it that describes some of the details of how it works.

    I'm not sure what you mean by "busy driving any servo". Servo channels can be enabled or disabled with a command (see the Guide). There's no command to tell you which channels are enabled or disabled. The servo controller is never really "busy" since multiple processors are simultaneously handling different tasks. One does the serial I/O to communicate with the host. One does the pulse generation for the servos. One does the command decoding and one handles the ramping of servo positions. That leaves 4 for other purposes should you want to modify the firmware to add functionality.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2013-12-30 16:25
    To add to what Mike said, unless the channel has been disabled, the PSCU is always sending out pulses on that line to maintain the last position. This leads me to surmise that you're asking if there is a way to tell if the servo is in motion from one point to the next. Is that what you mean? If so the answer is no. The amount of time the PSCU takes to move the servo depends on the ramping speed. The RSP command only returns last set position, not where the servo may be on its way there.
  • MikeDYurMikeDYur Posts: 2,176
    Hello; I am new to the forum, but have been working Parallax products for five plus years, enjoyed every minute. My question concerns controlling a PSCU via propeller com. Logic levels have been addressed, what I can't figure out is what a command line should look like. BS2 has been no problem for me, but my goal is to control my robot with a Propeller and PSCU. If you could give me an clue on what a command line would look like, I can stop sweating this subject. Thank You.
  • Mike GreenMike Green Posts: 23,101
    Have you looked at the documentation via the links in my previous post in this thread? The documentation gives the commands needed and their format. The 2nd link is to the source code (firmware) for the PSCU which you can modify if you're not happy with the standard code.
  • Buck RogersBuck Rogers Posts: 2,178
    I'm not new here. But is this a new product? I can't recall seeing any announcements for it.
  • PublisonPublison Posts: 12,366
    edited 2015-10-10 16:07
    I believe he is reffering to this:
    https://www.parallax.com/downloads/propeller-servo-controller-guide

    A discontinued item, but using the firmware, a Quickstart, ProtoBoard, ProjectBoard) board could be used, ( with some software modification for pins), to do the same thing.
  • MikeDYurMikeDYur Posts: 2,176
    Thank all of you for your response. I figured this out this morning, with the help of a spin I downloaded awhile back. It is called "ServoControllerSerial.spin, v2.0 By Austin Bowen (c) 2009. Along with a logic level converter from Allelectronics, my robot is totally under propeller control. Thank's again, I am finding alot of new info on the forum.
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