Due to my limited personal time, this document is still in progress. So stay tuned!
This project already has a working "release" but I haven't make it a real release yet. There will be updates to all components and firmware as I'm trying to make it better. Luckily, there hasn't been any big mistakes so far. But still there's a chance I will make some, which may lead to your time or money loss. This open source project is provided as is, I can't promise anything.
For following prints, FDM, PLA, 0.4 nozzle, 0.16-0.2mm layer, 4 walls. And very important: "Seam Position" should be set to "**Random**" in your slicer, not only it looks better, it makes the bearing-flange coupling smoother and tension distributed more evenly.
* Option 2 (Choc V2 only): FDM, PLA white, 0.2mm nozzle recommended but 0.4mm nozzle works too, 0.10~0.16mm layer, use easy-to-remove material for support, like "Bambu Support W" or just PETG.
* It's very easy to miss the USB pins of the Raspberry Pico Pi, it's at the other side. And it's difficult to solder as you may leave an airbubble in the soldering hole. My trick is to use sharpest iron tip, super-slowly apply solder wire only at one side. This is my result:
* You can use level shifter (SN74LV1T34DBVR), or you can just bypass it by soldering a nearby resistor (10 ohm), or in early PCB version, short the two pads following the picture below.
Typical AS5600 development board comes with 3.3V configuration, we can't feed 5V to it directly, it would burn the AS5600 or the main Pi Pico. The GPIO we use to communicate with AS5600 can never go beyond 3.6V. So we need a lower voltage, I chose REF3030, a precise 3.0V voltage reference.
You need to scrape off some solder mask to expose the ground copper (don't scrape the solder mask under 5V pin). I found a good place to mount the REF3030, this is how I handled it:
* If you go with digital (magnetic pogo pin connector)
There're a set of I2C and a WS2812B signal line together in the cable that connects turntable and the keyboard. Unfortunately, these signals crosstalk. So, we have to use shield cables for them. Two I2C lines should have a shield cable, and the WS2812B signal should have another shield cable. Good thing is, an HDMI cable has 4 shield cables and bunch of other small cables. We can make use of it.
The "ANGLE" connects to the AS5600 analog OUT. You need to remove a resistor from as5600 board to get OUT pin working.
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Note: For analog, crosstalk maybe no longer an issue, but ground level becomes a new concern. When driving the turntable LED ring, there's a considerable amount of current travelling through the ground cable which lifts AS5600 ground level. There're two ways to handle this.
* One is to use a 5 wire cable. You need to separate LED ground from the sensor ground. A typical Type-C to Type-C cable has 5 wires inside. You can use red and black to power the LED and others to serve sensor ground, sensor analog out and LED signal.
* The other one is to minimize the ground wire resistance. A metal braid shielding cable can be used with the metal shield serving as the ground line. Or you can find a 4 wire cable with thick core copper.
A little trick here. As the PCB footprint is made to support both choc v1 and v2, that leaves some wobble space for choc v1 and makes it difficult to align. So leave the key switch unsoldered, when the stabilizer, the key switch and the keycap are all in place, push the keycap down and then solder the key switch. This way the key switch will be aligned to the stabilizers better.
* For the new build, hold the BOOTSEL button while connect the USB to a PC, there will be a disk named "RPI-RP2" showed up. Drag the uf2 firmware binary file into it. That's it. There's a small hole at the back side of the keyboard, it is facing right to the BOOTSEL button.
* If it is already running my IIDX firmware, hold two small AUX buttons together will do the same as the BOOTSEL button.
**Solution:** I figured out another connector choice, which is a 3.5mm 4P headphone jack. It uses analog to communicate turntable movements, but I'm still testing it, so stay tuned. I will update this document.
**Solution:** There're many online vendors and people providing paid Bambu printing service. Or you can just use other 3D printers. It's just the numbers in the OpenSCAD source file or STL files are finetuned on my Bambu Lab X1. You may need to adjust a little on your 3D printer system to get perfect result. And regarding the multi-color thing, maybe you can just paint the top layer by hand. I know people do miniature painting, I think it would be similar.
**Solution:** 3D printer systems are different one from another, it results in small differences even with same model file and some configuration. If the printed parts are not happy with each other, you can fiddle with the OpenSCAD source file and the numbers in it for your case.
**Solution:** OK, this is an electronic hobby project, maybe it's not for you if you don't plan to do electronic DIYs. There're many good IIDX controllers you can purchase somewhere online.
