In today’s episode of Diminutive Device Technology Overview, [Sprite_TM] is at it again – this time conquering the HC32L110. A few weeks ago, we have highlighted the small ARM Cortex M0+ microcontroller, which is outstanding because of its exceptionally small size. We also pointed out a few hurdles, among them – hard-to-approach SDK and documentation, and difficulties making and assembling a PCB for such a small BGA. Today, we witness how [Sprite_TM] bulldozed through all of these hurdles for all of us, and added a few pictures to our collective “outrageous soldering” galleries while at it.
First, he figured out an example layout for this MCU that’s achievable for us even on a cheapest 2-layer board from JLCPCB, keeping distances within the generic tolerance standards by snubbing out a few pins. As a result, we only lose access to four GPIOs – those will have to be kept as inputs, so that nothing burns out. However, that’s the kind of tradeoff we are okay making if it helps us keep our PCB small and lightweight for projects where these factors matter. After receiving the resulting board, he also recorded a short tutorial on soldering such packages at home with a mere hot air gun and a few bare necessities like flux and tweezers – embedded below.
It doesn’t end there, however, as he decided to work around the GPIO fanout limitation in a non-intended way. Evidently, [Sprite_TM] decided to have some fun, taking a piece of regular 0.1″ spacing protoboard and deadbugging the chip with magnet wire, much to our amusement. The resulting contraption, pictured above, worked – and this is ever something you’d like to be able to achieve yourself in times of dire need, whether you make something work or simply to be entertained by making use of a cursed mounting technique, there’s an one-hour-long livestream recording of how this magnet wire contraption came to be. And, of course, that wasn’t the last thing to be shared.
As a finishing touch, he has published bindings and wrappers for Huada SDK so that the chip is usable with GCC, GDB and OpenOCD. He also added datasheets to the same repository – auto-translated but quite readable. All-GPIOs-involved blinkie GIF of a magnet-wire-bound chip triumphantly concludes the write-up.
An addition to [Sprite_TM]’s toolkit is an addition to everyone’s toolkit – the techniques, the insights, and the resources are all here for us to learn from. If you ever doubted your ability to work with small packages in general or this MCU specifically, now you have a whole lot more material to draw upon!
Wondering what kind of miniature device you might want to make? We hackers have mostly been having fun so far, building things like the USB-cable-hidden RubberDucky or a miniature PDP11, but there must be applications in, say, the wearable or medical fields where such a small MCU would prove itself to be a hacker’s friend. Maybe you want to build an LED engagement ring with some Cortex-M0+ smarts? In fact, this microcontroller is small enough that it wouldn’t be hard to hide inside your PCB itself.