RasPiCube

16/5/25

Update 1/1

In around 30 minutes I managed to create a Prove-of-Concept (PoC) version of a 3x3 Rubik's Cube scramble generator. The code is pretty simple and straightforward, so I'm not gonna waste time describing how it works.

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Update 2/2

Another 1 hour and a bit, a proper timer and scramble generator was born. I integrated the old scrable generator into the new program, by importing it as a module.

I kind of struggled at first to make the timing work, because the code on line 31 somehow redefined the time module, which gave me wheird errors:

Traceback (most recent call last):
  File "/home/qincai/PicoCube/test.py", line 76, in <module>
    main()
    ~~~~^^
  File "/home/qincai/PicoCube/test.py", line 51, in main
    start_time = time.time()
                 ^^^^
UnboundLocalError: cannot access local variable 'time' where it is not associated with a value

so i changed time to solve_time :))

Another challenge was to display the real-time timer, which every rubiks cube timer should have. In the older real-time version of this program, the user had to press CTRL+C to trigger the timer stop, which is not ideal. Fortunately I worked that out as well, using threading

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19/5/25

Update 1/3

After about 1.5 hours of hard grind, behold -- the PiCubeZero. Okay, im not even sure if it works or not, since I don't have the necessary hardware to build the project physically. That also means there is no pictures to share :((.

The process was pretty straightforward, since there is sooo much documentation on the Internet about the modules I was/am after. I fed the completed program into GPT-4.1 to check for any mistakes and suggestions, and good -- no big mistakes, but a few changes were made, such as the font selection thing I do not know how it works, or if it's supposed to work...

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Update 2/4

Another 50 -ish minutes later and I (sort of, and the stupid GPT-4.1 helped me a lot) made a version of PiCube, called PiCubePico, since it is based on the Raspberry Pi Pico MCU. Check it out here on Wokwi Simulator: https://wokwi.com/projects/431347174552980481

Screenshot:

(pls ignore the inconsistency between the OLED screen and the 7-seg display. The simulator is extremely laggy, with one second simulated being 15+ secs in real life)

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Update 3/5

Spent like 1.5 hours creating the BOM, and it is not even complete (yet). Here is the BOM for RasPiCube - PiCubeZero: https://github.com/QinCai-rui/RasPiCube/blob/PiCubeZero/BOM.md

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20/5/25

Update 1/6

Just updated the RasPiCube - PiCubeZero program to use a Waveshare 2-inch IPS LCD Display (ST7789, 240x320), instead of a tiny SSD1306 128x64 OLED display. This time GPT-4.1 helped me a lot when updating the program since I made quite a lot of mistakes.

Time spent this session: ~1.5 hours

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Update 2/7

For this session, I worked a lot on the PiCubeZero's BOM. I tried comparing the items I need on Aliexpress and Amazon. I almost got scammed by (likely) a scam on Aliexpress. Link

The Sandian branded uSD cards look sooo similar to the real SanDisk ones.

A quick Internet search revealed that...... SanDian is a scam. WHOO HOO. /j

Here are the posts: post1 post2

Maybe just don't buy uSD cards from AliExpress... Buy them on Amazon instead ig.

Time spent this session: ~1 hour

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Update 3/8

Since I couldn't find one single NeoPixel (as in 1 LED), I decided to switch to a common-cathode RGB LED. Simple! Also saved a bit of cash....

Time spent this session: 25 minutes

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21/5/25

Update 1/9

Updated the BOM to include all needed parts. This project is gonna cost a lot with a Pi 0 2WH, a battery, and a screen... (about $100 USD atm).