[ros-users] Novint Falcon, HAPI and ROS

[Brian Gerkey]

On Wed, Mar 24, 2010 at 9:50 AM, cuenta altas <miguel.register at gmail.com> wrote:
> I'm trying to use HAPI to create a node that manages a Novint Falcon haptic
> device.
> The problem is that haptic rendering doesn't work at all when I manage the
> device from a ROS node, while almost the same code (without all the ROS
> stuff) works fine from a standalone process.
> I know that HAPI internally spawns a separate thread to manage the device at
> high frequencies (~1 kHz). I also know that the way it does it is through
> another library (distributed with HAPI) named H3DUtil, which in turn uses
> pthreads. I suspect there must be some kind of interference between the
> thread that manages the haptic device and ROS, but I'm not comfortable
> enough with any of them (HAPI or ROS) to be able to speculate any further.
> Has anyone had any experience with this library before and experienced
> similar problems? And if nobody has, does somebody have any suggestion on
> which way should I go to try to fix this?

hi Miguel,

I'm not familiar with that library, but I'd surprised if the threads
were interfering with each other.  It's more likely that when you're
using ROS, you're not calling HAPI's event loop.  Can you post the
code that works and the code that doesn't?

	brian.