Request: Connect one remote to multiple hubs

[Stuckalf]

Hi all,

I know this has been asked before... but I think it would be a great feature to get a connection between one remote and different hubs (on different BT channels).

I'd guess quite a few Powered Up users are using the system to control their trains. And it is a nice feature (of the original Lego firmware) to switch between five different hubs - all connected to one remote. Even ten hubs are possible if you pair them within the five available channels that the Lego system offers - so you could control up to ten trains with one single remote.
Controlling ten trains at the same time might not be the case for a normal train scenario. But two or three trains can be a typical usecase, even in a home environment. And I'm talking about different trains, not a single locomotive with multiple engines.

I couldn't figure out how the Lego firmware solves the problem. There is some kind of broadcast going on in the Powered Up system. But if multiple hubs can establish a connection to one single peripheral, each on a dedicated channel, a broadcast on an advertising channel would be unneccessary for this usecase.
Afaik connecting one peripheral (the remote) to multiple central devices is available since BT BLE 4.1. And the Lego developers seem to have done quite a good job on this topic.

Greetings, Alf

[laurensvalk]

Thanks! See this post for an example to do it: pybricks/pybricks-projects#96

Since it's wireless, you can use this for a multi-engine train or for any number of trains.

I guess it amounts to putting up a few good examples on the site. Besides the multi-engine case, what is your preferred use case?

I just ordered a few train motors, so I hope to be making a few more examples.

[Stuckalf]

Thanks Laurens, but I think you've got me wrong.
I'm not searching for a multi-engine option for one locomotive. I'm thinking about switch between whole trainsets or locomotives - which indeed is possible with the original Lego firmware. Each hub connects to the remote on a different BT channel.
It would be nice to get the mail train up and running and - by switching to another hub e.g. locomotive - do the shunting job in the railyard.

In the DCC ecosystem you sometimes use one controller for a bunch of locomotives - so this is a normal way on controlling multiple trains.

[Stuckalf]

Maybe there's an option to read the current color value of the remote LED. So the script inside the hub could check if the selected "channel" on the remote (shown as color coding) corresponds with the color of the hubs own LED. This would be a kind of "id" to check if a button press on the remote is intended for a certain hub with the same LED color setting. Anything like this would be a good option for the case, that different channels aren't available.

[cimpeanioan]

I'm looking for something similar, to send a command from a remote control to 2 or more hubs (like a sync'ed trigger/master switch-on). It's possible with hub-to-hub communication, as I saw in the example of the PyBricks projects but I'd like to use the remote control instead of a hub.

[laurensvalk]

@cimpeanioan Here is an example of using one remote to control two hubs. https://pybricks.com/project/technic-42146-powered-up-remote/ The actual connection is still to one hub, which then passes it on to the other hub.

[cimpeanioan]

@laurensvalk thank you for replying!
I ended up using the remote just like you mentioned (already looked over the crane project):

• remote <-> central hub
• central hub -> broadcasting to multiple "auxiliary" hubs

The delay is not that noticeable. So far so good!

[laurensvalk]

Very nice!