Hot swap 1LC toolboard

Aurimas

so the question is - is it possible to restart the board without cycling power?
for instance while printing you disconnect the toolhead and the board reports that CAN20 stopped sending signal
then you reconnect the toolhead, so the connection is restored, but the board doesn't see it.
is it possible to reconnect the toolhead without cyucling power?

dc42

@Aurimas there are a few issues with disconnecting/reconnecting a tool board:

At a physical level, you will get a current surge when you reconnect power to the tool board, because the PSU is already providing its normal voltage output and the tool board has capacitors connected between VIN and ground. You can mitigate this by connecting a surge-limiting thermistor in series with the +VIN connection. If you don't do this then you are likely to blow the fuse supplying VIN to the tool board, or the tool board itself.
When the tool board loses power, it loses its configuration. It would be necessary to re-send the configuration when the tool board reconnects. I think you could do that by putting all the configuration relevant to the tool board in a separate macro file, then calling that macro both in config.g and in the handler macro for the tool board reconnection event. This will only work if the tool board is connected when you power up the machine, because no event is generated the first time a tool boards connect to the main board.
If you are thinking of using pogo pins to disconnect/reconnect the tool board, Stratasys has a patent on that.

Aurimas

@dc42 thanks a lot for the info.
I think i will give the macro a go
and no I am not using pogo pins - I am using USB cable.
I made a small PCB board to go on the extruder and a distribution board to split can signal into two feeds.
by using USB C 3.2 i think I can supply ennough current at 24V
if anyone is interested I could share the designs

ironhydroxide

@Aurimas That's pretty ingenious.
Though personally I wouldn't care about anyone's patent, so long as I'm not selling the equipment, or building and providing that equipment to potential customers of the patent.

Maybe I'm in the wrong with my thoughts, but to me most of this is a hobby and not stealing their profits.