Sharing a PanelDue between machines?

DocTrucker

Hi all,

Is it possible to share one paneldue with many machines? I've read someone discussing being what would appear quite rough with connecting and disconnecting a screen while a print was running which made me think it maybe possible.

I'd be thinking of something along the following in the most basic form:

Link the 0V across all machines.
Separate 5V supply for the screen, 0V linked to machines.
URXD0 and UTXD0 connection from each machine to a switch.

...and the process for switching would be:

Break 5V supply to screen.
Change switch to link TX/RX to another machine.
Make 5V supply to screen.

That being the most mechanical implementation. Doing the switching and power cycling through an Arduino would be likely to make it more idiot proof!

Comments?

I've not got the screen yet but I'm reasonably sure it's not a 7i, but one of the earlier models. I'm running on a tight budget at the moment so while a 7i for each machine would be great it's not possible at the moment!

dc42

That sounds workable, although rather than break/make the 5V supply to the PanelDue I suggest you connect a wire to the Reset button and activate that. But in your position, I would use a tablet computer running DWC instead of PanelDue. Somebody posted a thread about an extension to DWC for controlling multiple Duets.

DocTrucker

Hadn't considered the reset. I was concerned about how the control boards might respond to invalid gcode as it's likely that as you swap the commands make get sent half to one board and half to another?

Does holding the reset down keep the screen from booting or keep it in a continual reset loop?

I may keep the option to break the 5V line so I can power down the screen during a long build and save the possibility of me tapping the screen by mistake.

dc42

@doctrucker said in Sharing a PanelDue between machines?:

Hadn't considered the reset. I was concerned about how the control boards might respond to invalid gcode as it's likely that as you swap the commands make get sent half to one board and half to another?

If you use an Arduino to switch the serial data stream, it can wait until the serial data lines are quiet before switching the stream.

Does holding the reset down keep the screen from booting or keep it in a continual reset loop?

It keeps it from booting up.

I may keep the option to break the 5V line so I can power down the screen during a long build and save the possibility of me tapping the screen by mistake.

Danal

I'm one of the people who posted that I disconnect/reconnect PanelDue with no apparent issues. Including once doing a Panel firmware upgrade when the printer was in the middle of a very long (several day) print.

Of course, I can't say that you will or won't have problems. I can say that I've done it a lot, and that to my best understanding of the TTL serial hardware and the data exchanged, I'd not foresee any "gotchas".

brunofporto

@dc42 Please, would hold Reset at PanelDue a good way to "hot remove" PanelDue while the printer is working?

I would like to update it today (I need to bring to my home at my windows PC as I can not make it update with Ubuntu here at work.....) but the printer is in the middle of a long print.

Thank you!

dc42

I recommend that you pause the print before you disconnect or reconnect the PanelDue. That way, a resurrect.g file will be created, giving you a chance to recover is something goes wrong.