Serial connection between two proffieboards

Minor spoiler warning regarding Jedi: Fallen Order!


Not quite sure if this is better kept under ProffieOS or Proffieboard.

I’m planning to build a lightsaber in the style of the saber at the end of Jedi: Fallen Order, so separable into a relatively long main saber with a short additional hilt, making it a double lightsaber.

For this I am currently planning to have a master-slave system of two sabers that work individually, but when connected, both sabers react to the changes from the master. Both should still be able to be switched on and off individually, but color changes etc. in the master should be transferred to both sabers.

The plan so far is to use a serial interface of the proffieboard.

I have the following questions:

  1. how many connections would be necessary? For one direction I only need one transmission line and ground, correct? And for the possibility to send the changes in both directions then three: Send, Receive, Ground?

Maybe the 4-pin ShtokCustomWorx Battery and Speaker PCB would make sense as a connection, at least that’s what I’m planning so far. (If I have enough pins I will probably end up with less Master-Slave, but make it open in both directions, so it can also be used in normal doublelightsabers)

  1. does the serial interface already exist in ProffieOS or does it have to be created completely from scratch for such functions, and is someone already working on it? (I found a few threads mentioning the serial connection, but nothing specific)

  2. if there is no code for it yet, does it make more sense to wait for the Proffieboard V3 or still do everything in V2? (It’s not time critical, the saber doesn’t even exist completely in CAD yet) (Maybe also worth mentioning that I’m a very inexperienced programmer, not sure if I’ll be able to do it at all…).

  3. is it possible that changes to the preset etc. are also applied when the other saber is not switched on (not in deep sleep)?

  4. Maybe there is a way to even make this compatible with the Bluetooth modul? (Which would only live in the larger hilt)

  1. correct
  2. ProffieOS has support for a serial interface, but it’s fairly passive, it prints some debug information and awaits commands. For what you want, you would also want one of the boards to send commands to the other side, which would require additional code.
  3. V2 or V3 makes very little difference for this. Either would work fine.
  4. Yes, but with a wee bit of additional code.
  5. Bluetooth AND serial means you need multiple serial ports, at least on one of the boards. I’m not sure if a V2 can do that or not. A V3 board can though.

PS: I don’t mind helping with some of this. I’ve been wanting to build a Maul saber along the same lines for quite a while, I just haven’t gotten around to it.

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Thank you

That sounds promising for the time being.

I think I’ll take a look at the ProffieOS code and read up on it. But I won’t promise that the whole thing will happen in the near future, it’s not the highest priority at the moment.

Regarding Bluetooth: The whole thing was more of an afterthought. I think I’ll leave it out for now, but I might keep a place for it in the chassis.

One more recommendation that might not be obvious:
I recommend putting resistors on the serial lines, similar to how we do it for neopixels. Ideally I think you should do something like a 1k resistor on both sides of the chassis to make sure everything is well protected. It also prevents one board from leaching power from the other through the serial port.