Hacker News

PCB devboard the size of a USB-C plug

2026-03-085:0426269github.com

AngstromIO, one of the smallest devboards out there, barely longer than a USB C connector, based on the Attiny1616 MCU. And a dual CH340 board for programming and debugging, and another devboard, b...

NameName

IOX-77 LOGO

AngstromIO is one of the smallest devboards out there, barely longer than a USB-C connector, based on the Attiny1616 MCU. 2 GPIOs as well as I2C lines are broken out. I made a dual CH340 programming board too, both for UPDI programming and debugging (one way Serial Communication). I also designed a breadboard friendly, experimentation board for the CH32V003, with a 4 by 5 charlieplexed LED matrix.

While the AngstromIO is a tiny devboard, yet powerful, that could be embbeded in any space constrained projects, the CH32 devboard is more an experimentation board, for me to learn how to program this awesome chip on the MounriverStudio programming and how to program a charlieplexed matrix. The Programmer is an all in one module, that will make debugging with the Serial monitor while programming easy: one board for both.

banner renders
  • One of the smallest devboards: 8.9mm by 9mm, USB-C included
  • Attiny1616 MCU, 16Kb flash, low power, arduino compatible (for basic libraries at least)
  • USB-C for power, runs at 5V
  • 2x RGB addressable LEDs (SK6805-EC15)
  • Pins broken out: SCL, SDA, PB2 (TX), PA3, +5V, GND, and UPDI for programming
  • Dual CH340E setup:
    • One for programming (set as SerialUPDI programmer),
    • One for debugging (Serial Communication, USB to UART)
  • 2 USB-C for data transfer, only the USB-C for Serial provides 5V to the board
  • On board 3.3V LDO
  • 3.3V/5V operating voltage selection
  • Breadboard friendly devboard
  • cheap 25cents CH32V003, Risc-V MCU, 26Kb flash
  • USB-C for power, the CH32 runs at 3.3V but PC6 and PC5 are 5V tolerant
  • On board 3.3V LDO
  • 4x5 charlieplexed LED matrix
  • SWIO programming, proper programmer required (WCH linkE)
PINOUT AIO no frame PINOUT CH32 no frame PINOUT PGM no frame

Arduino compatible, some libraries may not work, but some have been arranged/made by SpenceKonde like Wire (I2C) and tinyNeoPixel (for more information, see: https://github.com/SpenceKonde/megaTinyCore/tree/master/megaavr/libraries)

Programmed on the Mounriver studio IDE

PCB designed in EasyEDA Pro, 2 layers, 1.0mm thick, Purple soldermask All 3 designs panelized into one PCB.

SCHEMATIC

angstromIO 3d S3 angstromIO 3d S4 angstromIO 3d S6

panel front

panel back

Programmer PCB 2D CH32 Devboard top CH32 Devboard btm

Layout top panel Layout bottom panel 004 001 🚧 to be continued...

🚧 coming soon...

🚧 coming soon...

🚧 coming soon...

You can’t perform that action at this time.


Read the original article

zachlatta

Karma: 4008
...
 @Hacker__News
@hacker._news

Comments

  • By zachlatta 2026-03-0913:35

    This project was made by a teenager in https://blueprint.hackclub.com, a nonprofit program I'm helping run that helps teenagers learn PCB design and get up to $400 USD in funding to prototype and manufacture their designs!

    We just launched https://stasis.hackclub.com, another similar electronics program.

    If you know any teens that want to get into PCB design, please encourage them to join Hack Club and these programs!

  • By stephen_g 2026-03-093:30

    Title is inaccurate, it's really designed to be about the size of a USB-C receptacle , the plug is the other side (in this case the part of the cable that plugs in to this board)

  • By amelius 2026-03-098:362 reply

    Does anyone here know the reason why Pcbway stopped accepting credit cards? My colleague asked them but I recall there wasn't a clear answer. It is puzzling why they would make it harder to do business with them from outside China. Jlcpcb doesn't have this problem.

    • By bArray 2026-03-0910:432 reply

      It was either PCBWay or JLCPCB, but they had a "review window" where it was possible to make changes or cancel an order. They recently switched this to be an automated review, so there was no opportunity for corrections. It could be that the card companies blacklisted them after people started cancelling orders with their credit cards, because their UI stopped supporting the feature.

      • By Liftyee 2026-03-0911:44

        Ordered from JLC a few weeks ago, their "review" is still manual. You can select a "confirm production file" option to get a second chance too.

      • By crote 2026-03-108:111 reply

        Don't they have a rather exhaustive self-service review UI on submission? Allowing people to cancel after they already verified exactly what they were getting seems a bit excessive, no?

        • By greyface- 2026-03-108:531 reply

          I will review a board a dozen times, find no issues, submit it for production, then 5 minutes later discover an obvious bug. Characterize it how you will, the cancellation window has saved my bacon more than once.

          • By bArray 2026-03-1011:03

            Exactly this. You calm down, take a cup of coffee, marvel at your beautiful design, and then spot something out of place. The actual review has saved me a few times too, for example: "are you sure there are no copper layers in your PCB design?" - Doh! A few times they have raised issues regarding the limitations of their manufacturing capabilities, and this too has saved time and cost.

    • By auxym 2026-03-0913:46

      They had stopped for a while because they were transitioning away from using Paypal as a processor. A few weeks, maybe a month or so tops? I had to switch to JLC PCB for an order back in January, because they didn't support any viable payment method for me in Canada (tried to make a payoneer account, they don't do business in Canada).

      But I just checked and it seems that they now accept CCs again.

HackerNews

About