A Neopixel wiring question with blade id

[profezzorn]

Answers…

@jedi_j_stream

I was also planning to use this chassis in other hilts–so I thought I could add a 20k ohm resistor on the hilt side for this specific hilt (1/2W), between Data 1 and LED 2+3. My understanding was that these resistors would be additive so I could trigger blade configuration specific to the blade/hilt combinations: 50k for the quad blade, 70k for the quad blade and hilt chamber, 20k for this hilt with a different blade.

Not additive, since they are hooked up in parallel.
The formula is R_{measured} = \frac{1}{1 / R_{hilt} + 1 / R_{blade}}
Of course, none of this matters if you’re using the snapshot blade ID, since the values will be kind of random in that case.

More details here: All you need to know about electronics

@jedi_j_stream

can I wire the hilt pcb so the built-in LEDs are in series and still use Blade id?

no

@jedi_j_stream

If not, would it work with the V4 wiring option–blade and PCB LEDs are independent

yes

@jedi_j_stream

can the same pixels be assigned to multiple blades in the bladeconfig?

what? no, what would that even do?

@jedi_j_stream

I was thinking it could be useful to address the blade as a whole for some styles while others would only affect a section/side of the blade.

Addressing one “side” of the blade is only possible if you have a zig-zag blade.

Now for some options…

1. V4 will require one more wire, however, there are lots of very thin wires available, and data wires do not need to be thick. 30-awg PTFE wires are highly recommended. More information about wires here: The Wiring Selection
2. If you can’t do V4, you could have the PCB and the blade wired in parallel, this works reasonably well since you usually can’t see the blade and the PCB at the same time anyways, so you can use blade detect (or blade id) to select what to show.
3. You could potentially drop the blade detect pin and just rely on blade ID. We have code that can poll blade ID and detect when a blade is added/removed. However, it’s not quite as reliable as blade detect.