Bootlegger137 wrote: ↑March 24th, 2024, 8:18 amsremick wrote: ↑March 6th, 2024, 1:08 pm
Hey, Shawn. Am wondering if you made any more progress on this in the last couple years.
I also was wondering this.
Thanks for being patient. I have made progress, but, of course, it's been slow. I bought a new batch of silicone late last summer in preparation of making new molds for the final shell, but weather and work weren't cooperative.
The PJRC Teensy 3.2 Arduino microcontroller on which my Mk I version of this prop ran is no longer in production. This gave me the opportunity to rework and upgrade a bunch of stuff to produce a better prop.
I replaced the Teensy 3.2 with an Adafruit Itsy Bitsy M0 Express. Patrick Benton did the coding again but this time using Circuit Python; it was a struggle getting everything to fit in its paltry 32 KB of RAM.
I replaced the five 1.2V 2/3 C cell NiMH batteries with a single 3.7V 2200 mAh Lithium Ion battery that can just live in the handle, leaving space for a much bigger speaker in the main shell. I’m using a small Adafruit LiIon charger board to manage the charging (the NiMHs required an outboard charger).
A 3W Class D I2S amplifier board from Adafruit drives the 5 cm speaker. It's much louder than my Mk I prop.
I’ve switched to micro servos that also free up more space (though they’re somewhat noisy).
By incorporating two shift registers into the circuit I can change the chase pattern on the wings from the GB1 pattern to GB2 with the touch of one of the touchswitches.
This Itsy Bitsy has built-in capacitive touchswitches, whereas I had to incorporate extra components for resistive touchswitches in the Mk 1. These capacitive ones seem to be working reliably. With the old resistive touchswitches if you got caught in the rain, or even a light sprinkle, it would trigger the arms and you couldn't home them until you dried off the unit.
I designed in KiCad and had OSHPark fabricate a new main PCB along with a smaller board that combined the LiIon charger board and a Polulu boost converter to regulate and increase the battery voltage from 3.7V to 5V. This also includes a circuit to drive a charge status LED in the handle that glows red when charging and green when complete.
I modeled and 3D resin printed a thing to hold the speaker, for now just epoxied into the shell. Perhaps I'll mold that into the master before making the molds.
I’m looking to make some tweaks to my Iona buck at which point I’ll make new silicone molds to crank out more resin shells. The main issue is the display "hood" is just a TINY bit asymmetrical on my buck/master. My plan is to model and 3D print one, but SLA UV resin doesn't play nice with platinum-cure silicone, so I'll have to jump through a bunch of hoops to graft a new display piece to my master and pull clean molds.
I've taken this Mark II to multiple cons and events since September, 2023, and it's behaved perfectly. I'm hoping that as the weather gets nicer for molding, casting, and 3D printing I get start making kits.
Cheers.