Blade Detect (and Blade ID) for thin-neck sabers

Hey everyone. I while ago I managed to get Blade ID to work in a thin-neck saber. However, I quickly found the limitation of Blade ID (not being able to change presets/states instantly in different situations). Perhaps if I also wired for Blade Detect, it may have been able to change presets instantly).

Which brings me to my next issue. I’ve been brainstorming about the possibility to get Blade Detect to work in a thin-neck saber. With the available Shtok NPXL connectors, I can get Blade Detect to work in the grenade PCB. However, I was wondering how to get Blade Detect to work in the emitter PCB as well, especially if you only have 1 data line to work with?

My plan would be to use a Shtok 10-pole connector that can be wired to use Blade Detect and Blade ID for a removable chassis. The effect I want to create is to let the saber play the bladein.wav whenever the grenade is screwed on and/or when the blade is inserted in the emitter. If I wire the grenade PCB and emitter PCB in V3 config, I’d get two different “blades”:

  1. Grenade as 1 “blade”
  2. Grenade + blade as 1 “blade”

So, for this setup my questions are:

  1. Will Blade Detect work in the emitter (and in the grenade) with a thin-neck saber?
  2. Do I need to combine Blade ID and Blade Detect to get real-time changes/detections of different “blades” (mentioned above)?
  3. Will I need to use a resistor in the emitter PCB to treat the grenade + blade as one single “blade” (provided that both PCBs are in V3 config), or can it be omitted in this case?
  4. If this is all possible, can it be done with just 1 data line?

By default, blade detect only supports one detection, so detecting both the insertion of the grenade, AND detecting the blade insertion isn’t going to to work. That doesn’t mean that it can’t be made to work though making it work on one line will require some trickery though.

Normally, blade detect is hooked up to the “GND” line on the neopixels. This turns out to cause complications, because we turn the negative on/off when we power the blade. Because of this, the blade detect is made to trigger either when the blade is held high OR when it’s held low. To make what you want work, we would want to use high and low for different things…

So, first, you would need to cut a trace on the pogo pin PCB so that you can use one of the + pins for blade detect instead of one of the - pins. Since + doesn’t turn on/off, we now know that the blade detect will go HIGH when the blade is inserted.

Second, you would add a ~4.7k resistor between GND and blade detect in the grenade section. This will pull the blade detect LOW when the grenade section is connected. This resistor will still be overruled when the blade is connected.

Then we would need to update the code to treat HIGH and LOW differently. If you decide to do this, I can help with the code part.

You’ll still need two wires though: One for data and one for blade detect.

I actually just finished installing a 7Chambers MoM, and I used a Shtok NPXL connector in the emitter, but inside the “grenade” section, which detaches from the lower body, I used a Shtok battery/speaker connector. This is a four-line connector with two outer rings for the positive and negative battery connections (with five pogo pins each for throughput), and two inner rings for the positive and negative speaker terminals. I simply used the positive speaker connection to connect to the blade’s data line, and the negative speaker connection as a passthrough for the blade detect pin.

This way, if the “grenade” section is disconnected or if the blade is removed, the blade detect pin is triggered. Works perfectly.

I guess that with all those “mods”, I could get Blade Detect and Blade ID to do exactly what I want. Though that would require more modifications than I’d like. So I’ll have to think this and weigh my options.

Hm, that could work. I know about that particular connector. The only downside would be that I’d lose having LEDs on top of the grenade section. Having just the crystal and plasma gate lighting up may not be “flashy” enough, if you know what I mean. Unless it’s still quite bright without the PCB LEDs, then it’s something to really consider.