GI Dice element dice V1.3

# GI Dice V1.3
This is a low-cost DIY implementation of the elemental dice in Genshin Seven Summons (GI = Genshin Impact = Genius Invokation).
For usage effects and assembly processes, you can watch [this video] (https://www.bilibili.com/video/BV1Vs4y1V7eA)
In this design, except for the shell, element icons and PCB, which need to be given to JLC, the rest are all implemented using brand-new components available at Lichuang Mall or Taobao retail. , no additional customization is required.

The project homepage is at [Github: libc0607/GI_Dice](https://github.com/libc0607/GI_Dice). The source code, shell, BOM, assembly tutorial and other content will be updated one after another

! [WeChat screenshot_20230302151527 .png]

## Features
* Regular octahedron, side length 22mm
* CH573F master control, through Bluetooth broadcasting, multiple dice can simultaneously transmit dice orientation and battery information to the central control
* I don’t plan to use central control for scoring in card games, but I will give it A routine for receiving on ESP32-S3. If you want to do central control, you can directly connect it
* LIS2DW12 three-axis acceleration sensor
* 8 APA102 (SK9822) RGB LEDs, support turning off the LED power to save power
* LIR1240 55mAh lithium battery, As well as serious charging management and battery protection IC
* Use wireless charging, the matching charging box is [here](https://oshwhub.com/libc0607/gi_dice_charger_dual_nobat_v1_0_rel)
* The Hall sensor implements turning off the power after being placed in the charging box, this The power consumption is about a few uA per hour

## Production Notes
* The board thickness is 1.0mm, the default stacked structure should be free of charge, it is recommended to use SMT to paste the basic library + some extended libraries (acceleration sensor, protection and charging IC)
* Panel The printing is 0.8mm thick. As for the material, I tried two types and they seemed to be about the same. .
* The 2.2nF resonant capacitor needs to be made of NP0/C0G material; the external inductor is CD53 10uH, which must not be a closed magnetic circuit
* There is no need to solder the 32k crystal oscillator, and the 22uH inductor can be packaged in 0603 to reduce the thickness, which can be reduced to 10uH, but it must be a power Inductor
* Hall needs to choose a model with low power consumption and push-pull output. I use CC6203ST (C285997)
* Use 3P 1.0mm pitch 30mm long solderable FPC to connect the upper board and Hall sensor
* Solder the component surface first, then solder LED, it is recommended to use ~~Lenovo's same model~~ low-temperature tin soldered LED
* For programming via USB, you need to fly wires to DP/DN/BOOT/GND on the upper board, and use a magnet to restart when pulling BOOT low to enter download mode
* When programming, turn off the option to use RST as reset, and I treat that PIN as a GPIO
* After the programming verification function is available, cut the PCB from the middle, and remember to test whether there are adjacent short circuits
* Use 8P 0.8mm pitch 30mm The long weldable FPC connects the upper board and the lower board; these two cables are sold in the same store on Taobao (*cable warehouse)

## The overall assembly
structure is as follows:
![assemble-guide.png]
The shell STL will be uploaded later In the picture below on Github,
you can choose to use Φ2mm * 1.5mm magnets as auxiliary positioning posts in the four corners. It is also optional.
If you are not confident about the welder, it is recommended to change the battery to 301012, which will make it easier to cover
! [WeChat screenshot_20230302155035.png ]
## BOM
~~Too many to be too lazy to do, so to-do~~
see the attachment first, but I’m not sure if there is anything missing

## The development & debugging
source code will be uploaded to Github
for use [MounRiver Studio](http://www. mounriver.com/) for development, you can refer to Qin Heng's [this tutorial](https://space.bilibili.com/489340606/channel/seriesdetail?sid=474190&ctype=0) for quick start; API documentation and routines include In [CH573 EVT](https://www.wch.cn/downloads/CH573EVT_ZIP.html),
the debugger is WCH-Link. If you bought it from Taobao, you may need to switch to RISC-V mode first.
This board is small in size. It is not convenient to fly wires. If you want to develop, you can use my [this](https://oshwhub.com/libc0607/gi_dice_devboard_v1-2) board, which has the same schematic, but leads most of it through 2.54 pin headers Interface

## You may have questions about hardware?
Write these first, and then add them slowly depending on the situation; for some problems, you may have better methods, welcome to ask

Q: Wireless charging uses XKT for transmitting, why not for receiving?
A: The first version used it, and then My battery was charged to a very strange voltage. I don’t know if I made a mistake, so I changed it to V1.2
! [image.png]
Q: Why is wireless charging not Qi?
A: Size limit. I really thought about it, I found a CCX1121B, I saw the information on the forum, and after a long time of talking about it without providing the information, it was useless. Others are a bit big in size and cost.

Q: Why is there an inductor on it?
A: 1. Counterweight, 2. Push the sensor to the correct position, 3. Improve the sensor sensitivity.

Q: The charging indicator light is not visible from the outside. Does it need to be welded?
A: It must be soldered and ensure that there is ~1mA current on it to prevent the capacitor behind from exploding.

Q: The matching of this antenna is not done according to the antenna manual. Can it be used?
A: I can’t let it go. . In addition, the antenna is not given a simulation model, and the transmission power is only 0dBm. In short, the connection on the same table (correct application scenario) is fine; if only the 3nH inductance and the ideal 50 ohm are considered, as shown below, then the VSWR at this time There is also 2.4
![WeChat screenshot_20230218131019.png]
Q: 4.35V battery?
A: Both charging and protection ICs have high-voltage versions, just replace them.

Q: Why can't they close after I assemble them?
A: Replace with 301012 batteries, which are thinner.

## Known issues & solutions
to be added
1. The four corners will become loose after being thrown a few times. Peeling paint…. That. . Do n’t throw it

away
The charging circuit was inspired by this
* [CH573 EVT](https://www.wch.cn/downloads/CH573EVT_ZIP.html): Qinheng’s official document, including hardware design and various routines
* [@MANGO小强DY: Teach you how to achieve elemental dice freedom](https://www.bilibili.com/video/BV1S14y1K7hi), I directly used the drawings he provided for panel printing

##
In addition to the panel with element logos, the open source protocol All other hardware designs are based on [CERN-OHL-S v2](https://ohwr.org/cern_ohl_s_v2.txt) or any later versions. Open source
is prohibited from being used for graduation projects. You also don’t want your defending teacher to know about your daily work. In fact, just play cards in Genshin Impact (
Although I chose this agreement, I currently have no plans to mass-produce and sell it. I hope you can make it yourself; DIY is risky, so please be careful when placing orders.