There are still a few issues that I need to solve:Powering. I currently use the DC-DC Adjustable Step-up Module to boost the voltage to 4.7V, but the buck seems to have quite significant power loss. I haven't measured it precisely yet, but its efficiency seems to be around 50% around the current/voltage that I use.I am thinking of using 2 x 10440 batteries that would give me 6.5-8V range, but in that case, there would be more than 50% loss in the MOSFET LED driver (or on the resistor if you are using just a resistor), so there's no benefit in that either. But, I also have a step-down buck that I need to test for efficiency, so that might make things better.Alternatively, the Kyberos Mk2 will be using Cree instead of Luxeon Rebel LEDs, and these suckers work on lower voltage. Perhaps I'll just try powering the LED drivers directly from a single 18650 battery.
Voltage drop on the kill-switch varies significantly with the current (from 0V to 0.3V), what messes up the LED driver currents and the readings of the ADXL335. My kill switch currently disconnects the BAT- from the GND, allowing me to connect an external charger adapter, but it causes the voltage drop problem. I am thinking of either moving the kill-switch from BAT- to BAT+ (fixing the floating LED Driver GND issue, but loosing the possibility to use an external charger), and/or making an electronic kill switch that would have a voltage drop independent from the current.
Measuring Li-Ion State Of Charge (Battery Level) is a project of its own. There are quite a few whitepapers and doctor theses on the subject. Still working on a reliable implementation
Light Diffusion Foil is another thing I am working on. The plain wrapping foil does not give even distribution and is not good enough in the daylight, so I am experimenting with some modifications of the wrapping foil that should dramatically improve its efficiency.
Hi guys!Thank you very much for developing the thread and saber building!I have done my first build on WT588d-u, and now converting to DFPlayer mini and having some issues, so I would really appreciate your advice. The current issue, as I assume, is with powering the whole setup. I use:Arduino pro micro 5v/16mhz2x CR123A 3.7v 1000mahDFPlayer miniMPU6050Red high power LEDHow do you think, would it work ok if I power it all with only one CR123A, using a DC-DC stepup to 6v for arduino, stepdown to 2.4v for the LED, stepup to 4.2v for DFPlayer mini and MPU6050 straight with 3.7v from CR123A?Or should I keep on using 2 CR123A's?I already consider ordering 3.3v arduino, but I'm afraid it will not reach me until Halloween...Big thanks guys!
I'm interested in trying to build a bluetooth-enabled system. Before going through this thread, this is what I was leaning towards using:Bluefruit Feather NRF52: https://www.adafruit.com/product/3406Sound/SD: https://www.adafruit.com/product/3436Gyro/Accel: https://www.adafruit.com/product/3463Neopixel Jewel for LED: https://www.adafruit.com/product/2226Surface Transducer for speaker: https://www.adafruit.com/product/178518650 Battery: http://www.thecustomsabershop.com/Panasonic-Li-Ion-18650-37V-3400mAh-PCB-Protected-Rechargeable-Battery-P853.aspxIt doesn't look like anyone has really used any of those components. I was hoping to get some input on whether this setup actually made sense, or if there are better options. A few specific questions:1) Does a surface transducer make sense? It seemed like an interesting idea, and I saw somebody ask about it, but never saw a follow-up. Is it better to just go with a tried-and-true speaker for a lightsaber?2) I think my main sticking point so far is choice of sound. I'd much prefer a non-SD card option, but would probably 100MB-1GB to allow sufficient space for a few different configurable fonts. I haven't seen any good options for that. I'm also curious whether anyone really notices issues in practice with sound playing one after another, rather than mixing (say, keeping the hum sound always going and mixing in clash/blaster/etc). I'm more of a software guy, so any input on whether the above setup seems practical (or if there are other things I should look into instead) would be greatly appreciated!