Dan,

There is a pulse parameter on the ros parameter server for the p2os node
(see p2osnode.cc line 49 for where it is defined).

If you set this value to something other than -1.0 it should send the pulse
(see p2osnode.cc line 725).

Adding the following line to the p2os node in your launch file should do the
trick:

<param name="pulse" value="1.0"/>

-Tucker

On Tue, Apr 27, 2010 at 6:35 PM, Dan Lazewatsky
<lazewatskyd@cse.wustl.edu>wrote:

> No luck setting pulse to 1 (I'm assuming you're referring to the PULSE
> parameter in robot_params.h)
>
> -Dan
>
> On 4/23/10 2:39 PM, David Feil-Seifer wrote:
> > I wrote the node, but a while ago, so I can't be sure, but Ithink that
> > I sent a "pulse" message every 1s to keep that watchdog from kicking
> > in. However, by default it is turned off. Try setting the "pulse"
> > parameter to 1.
> >
> > -Dave
> >
> > On Fri, Apr 23, 2010 at 8:24 AM, Brian Gerkey<gerkey@willowgarage.com>
>  wrote:
> >
> >> It's been a long time since I used a Pioneer, and I haven't looked at
> >> the node that you're using, so this is shooting in the dark:
> >>
> >> If I recall correctly, the microcontroller implements a watchdog that
> >> will stop the motors if it hasn't heard a velocity command over the
> >> serial line after a certain amount of time.  If you send commands too
> >> slowly, the watchdog would kick in between commands, causing the robot
> >> to move a bit, halt, move a bit, halt, etc. I believe that the
> >> watchdog is configurable, or at least can be turned on or off, which
> >> might account for the different in behavior between your robots.
> >>
> >> Something to try is to make the node resend the last received velocity
> >> to the robot at a relatively high rate (10Hz should be enough).  Of
> >> course, the node should then implement its own watchdog, which would
> >> send zero velocities if it hasn't received a command via ROS after
> >> some time.
> >>
> >>         brian.
> >>
> >> On Fri, Apr 23, 2010 at 6:56 AM, Tucker Hermans<thermans@cc.gatech.edu>
>  wrote:
> >>
> >>> Dan,
> >>> Without being able to investigate your setup further, the only thing I
> can
> >>> think is that the commands being sent over the serial connection are
> either
> >>> experiencing high latency or are being sent to infrequently, so that
> the
> >>> velocity commands sent to the microcontroller are far enough apart that
> you
> >>> get the stuttering effect.
> >>> I tried reproducing this by setting a very high time (30s as opposed to
> 2s)
> >>> to resend velocity commands but this had no effect.  Are you seeing
> >>> statements from the p2os node of the form "new speed [0.25, 0.0]
> >>> (timestamp)" and "setting vel: [0.25,0.0]".  If not what kind of debug
> >>> output are you seeing on the node?
> >>> -Tucker
> >>>
> >>> On Thu, Apr 22, 2010 at 12:31 PM, Dan Lazewatsky<
> lazewatskyd@cse.wustl.edu>
> >>> wrote:
> >>>
> >>>> I just tried out a few things from your pioneer_control package and I
> get
> >>>> the same behavior I was seeing before.
> >>>>
> >>>> -Dan
> >>>>
> >>>> On 4/21/10 7:13 PM, Dan Lazewatsky wrote:
> >>>>
> >>>> Hi Tucker,
> >>>> I think that should be enough to get me going.
> >>>>
> >>>> Thanks!
> >>>> -Dan
> >>>>
> >>>> On 4/21/10 6:57 PM, Tucker Hermans wrote:
> >>>>
> >>>> Hi Dan,
> >>>> I send the MotorState command of 4 and have no problems.
> >>>> I have a teleop keyboard port which I use for communicating with the
> p3dx
> >>>> that you can find
> >>>> here: github.com/trhermans/AffLearning/tree/master/pioneer_control/
> >>>> Note: the launch file is setup for a p3dx with a PTZ connected to an
> >>>> onboard computer and uses the probe camera driver to get the video
> stream.
> >>>> I have only been testing the changes to the p2os package on a p3dx
> with an
> >>>> onboard computer, I don't think this should have any issues, but it
> could.
> >>>> Let me know if the keyboard operation gives the same problems you have
> now
> >>>> and I'll try and help debug it.
> >>>> -Tucker
> >>>>
> >>>> On Wed, Apr 21, 2010 at 7:49 PM, Dan Lazewatsky
> >>>> <lazewatskyd@cse.wustl.edu>  wrote:
> >>>>
> >>>>> Hi all -
> >>>>> I know this has been discussed here a bit, but not in much detail.
> >>>>> We have a Pioneer3dx that we'd like to get up and running again. I
> >>>>> downloaded and compiled the p2os package which seems to be able to
> >>>>> successfully connect and communicate with the robot using a serial to
> >>>>> USB adapter. However, I'm having trouble getting the motors to do
> >>>>> anything sensible. The robot's motor self-test looks like it works
> fine,
> >>>>> but sending cmd_vel, all I can get is extremely slow, jerky movement
> >>>>> forward or backwards (no turning). I enabled the motors with:
> >>>>>
> >>>>> rostopic pub cmd_motor_state -1 p2os/MotorState 1 (I also tried 4
> >>>>> instead of 1 which was mentioned in a previous discussion)
> >>>>>
> >>>>> This feels like a communication problem between the motor commands
> p2os
> >>>>> is sending and the robot, but I don't know what's going on. Any
> ideas?
> >>>>>
> >>>>> Thanks,
> >>>>> -Dan
> >>>>> _______________________________________________
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