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• Change is the end result of all true learning

  Vincent • 10/28/2025 at 21:22 • 0 comments

  Johnny554: Moving Forward with the CH554

  With the lessons learned from our first round of Johnny552 prototypes, it’s time to evolve. For the next revision, we’ve decided to move away from the CH552 microcontroller and adopt its more capable sibling, the CH554.

  The CH554 provides additional flexibility, slightly expanded peripheral options, and better long-term support potential for future firmware experiments. While the CH552 proved itself a solid starting point, this shift opens more room for optimization and feature growth without significantly changing the board’s core design philosophy.

  This hardware change naturally comes with a project rename — Johnny552 is now officially Johnny554.

  What’s Changing

  • Microcontroller: CH552 → CH554

  • Documentation and Schematics: All instances of CH552 will be updated to CH554.

  • Firmware: Adjustments for register definitions, USB initialization, and peripheral mapping.

  • Silkscreen and BOM: Updated identifiers for the new MCU.

  Next Steps

  • Validate the first CH554-based prototype batch.

  • Confirm USB and onboard peripheral operation with the updated firmware.

  • Begin preparing firmware examples specific to CH554’s extended features.

  Johnny554 continues the same goal: an accessible, hackable IoT development board built around a compact, capable 8-bit USB MCU — now with more headroom for experimentation.

• Everything should be made as simple as possible, But not simpler

  Vincent • 05/14/2025 at 11:46 • 0 comments

  First Prototypes Are Here!

  We finally got the first batch of Johnny552 boards back from the fab, and it’s been exciting to see them come to life. There’s nothing quite like holding a physical version of something you’ve spent weeks (or months) shaping in CAD.

  The CH552P microcontroller fired up beautifully, and the onboard SK9822 LED and AHT21 sensor worked out of the box. USB communication also worked — technically. But that’s where the story shifts.

  As we began plugging and unplugging the board, testing it on real USB-A ports (including some old-school servers and laptops), a flaw became obvious...

  
  

  Farewell USB-A PCB Plug (We Loved You)

  We had gone with a 2mm thick PCB edge to act as a direct USB-A male plug — a super minimal, connector-less approach. Even better, our design allowed the board to be flipped 180 degrees and still plug in, which felt clever and elegant.

  But in practice?

  • The fit was unreliable
  • It lacked physical durability
  • It could easily be bent or misaligned under stress.

  Despite loving the idea of it, we realized: it just wasn’t robust enough for real-world use.
  

  The Connector Is Dead, Long Live the Connector: Enter USB-C

  We’re moving forward with USB-C for version 2, and it’s already opening up new possibilities:

  • Reversible plug orientation (just like before, but reliable)
  • Support for modern devices (phones, tablets, newer laptops)
  • Much more mechanically sound

  For legacy systems, a USB-A to USB-C adapter keeps the board backward-compatible, so we’re not leaving anyone behind.

  We’ll miss the raw PCB plug aesthetic — but not the wobble, the risk of port damage, or the fragility.

  Coming Up in V2

  This is just one of several changes planned for Johnny552 v2, which will include:

  • Better mechanical design
  • More connectivity
  • Possibly some new onboard features

  We’re still testing the v1 board and refining our v2 layout, but we wanted to share this USB pivot early. It’s a good example of how cool ideas sometimes give way to practical engineering — and we’re okay with that.

  If you’ve got opinions on connectors (or horror stories), hit us up. Always happy to hear from other hardware folks.

  Stay tuned!

• Life is a mirror and will reflect back to the tinkerer what they wire into it

  Vincent • 04/14/2025 at 10:56 • 0 comments

  So. Monday. We meet again...

  As we eagerly await the arrival of our first Johnny552 prototypes, we took a moment to review our documentation. Thanks to our teammate @Anthony 's keen observation, we discovered that the GPIO pin labels in our v1.0 pinout diagram were mirrored—an oversight on our part. We've promptly corrected this, and the updated diagram (document version 1.1) is now available in the download section.

  We like to think of ourselves as reflective engineers, but this time, our reflection was a bit too literal.

  Let's just say we're proud to start the week strong—with a corrected pinout and a fresh cup of coffee.
  
  

• Johnny552 v1.0 Pinout Released!

  Vincent • 04/07/2025 at 08:50 • 0 comments

  We’re excited to announce the release of the Johnny552 Pinout Diagram – Hardware Revision v1.0! 

  Whether you're building your next DIY gadget, tinkering with USB devices, or diving into embedded development with the CH552P, this colorful, easy-to-read pinout is your new best friend. Every pin's function—PWM, UART, Analog In, Interrupts, and more—is clearly labeled to help you prototype faster and smarter.
  
  You will find the PDF in the download section. 

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