USB should be able to handle real time but think it is complex which might be a reason to avoid it and there are no support in Linuxcnc. There are however a lot of cheap development boards available which may make it a very cheap and good choice. There are standard protocol for keyboard and mouse but do not know about this kind of input you want.
Switching noise might be a problem if connected to power electronics but not to hand held device. There is Modbus available in Linuxcnc. It might be a little bit slow nowadays but expect it more than good enough for buttons. Think it is also simple and no problem to build a device using one of these development boards available but otherwise a Modbus Remote IO Module might be a good choice. Emergency stop, any plan for this? > I have actually been wondering about the same/similar thing, on how to > feed information into hall. > > On 6/4/20 2:33 PM, Chris Albertson wrote: > > I'd like to build a handheld pendant controller. I have some ideas about > > how it should work. One thing I want is an LCD screen. This could evolve > > into a "smart pendant" that can do things like move along an arc, rather > > than just one axis at a time. > > > > I think the best physical interface from a handheld device to the computer > > is USB. Is there a way to get data from USB to HAL? I could use a USB > > virtual serial port but then the question is getting serial port data to > > HAL. > > > > Maybe the best interface is wireless, so how to get data from a UNIX socket > > to HAL? > > > > Note that we don't need "hard" real-time to the computer. Latency of a few > > tens of milliseconds is acceptable for a human interface so this could be > > done in userspace. If so, then maybe all I need is a way to get data from > > an arbitrary Linux application to HAL. > > > > It just occurred to me that this "arbitrary Linux application" could be the > > Apache webserver. Then you run a browser on the tablet. > > > > Summary: How to move data from USB or serial or socket to HAL? _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users