All The USB You Can Do With A CH552

A page screenshot, showing all the numerous CH552 projects from [Stefan].

Recently, you might have noticed a flurry of CH552 projects on – all of them with professionally taken photos of neatly assembled PCBs, typically with a USB connector or two. You might also have noticed that they’re all built by one person, [Stefan “wagiminator” Wagner], who is a prolific hacker – his page lists over a hundred projects, most of them proudly marked “Completed”. Today, with all these CH552 mentions in the’s “Newest” category, we’ve decided to take a peek.

The CH552 is an 8-bit MCU with a USB peripheral, with a CH554 sibling that supports USB host, and [Stefan] seriously puts this microcontroller to the test. There’s a nRF24L01+ transceiver turned USB dongle, a rotary encoder peripheral with a 3D-printed case and knob, a mouse wiggler, an interface for our beloved I2C OLED displays, a general-purpose CH55x devboard, and a flurry of AVR programmers – regular AVRISP, an ISP+UPDI programmer, and a UPDI programmer with HV support. Plus, if USB host is your interest, there’s a CH554 USB host development board specifically. Every single one of these is open-source, with PCBs designed in EasyEDA, the firmware already written (!) and available on GitHub, and a lovingly crafted documentation page for each.

[Stefan]’s seriously put the CH552 to the test, and given that all of these projects got firmware, having these projects as examples is a serious incentive for more hackers to try these chips out, especially considering that the CH552 and CH554 go for about 50 cents a piece at websites like LCSC, and mostly in friendly packages. We did cover these two chips back in 2018, together with a programming guide, and we’ve seen things like badges built with its help, but having all these devices to follow is a step up in availability – plus, it’s undeniable that all the widgets built are quite useful by themselves!

11 thoughts on “All The USB You Can Do With A CH552

  1. Out of curiosity, since I have no suggestion that this is actually happening, I’m sincerely asking out of curiosity, what is the HAD editorial policy on sponsored projects?

    It occurs to me that publishing a bunch of example projects is a great way to promote a new chip, and frankly I think that’s great, but at some point I’d want to know if I was seeing a hobbyist project versus a professional placement. Not that it necessarily changes anything, but it’d be useful context, y’know?

    1. I have never read anything that could be described as a “HaD editorial policy document”, and I am not responsible for HaD’s editorial policy in any way. However, here’s my experience – we go by whether something is useful to hackers, and a library of fully open projects for a perhaps underexplored chip sure fits the bill! IDK if “sponsored project” is meaningful – I’ve personally covered a few “these PCBs have been provided by BestPCBEver service, here’s an affiliate link” projects before. In my experience picking projects to cover, what matters way more is whether a project, as published, would be to our audience’s liking – the “sponsored” factor is at most, a paragraph in a worklog or up to a minute in video length when it comes to its impact. It’s been my impression that other writers follow the same principle, and if you pay attention, you can likely notice it.

      As for specifically this article, this chip is far from being a new chip, and the outro suggests as much! I haven’t seen any sponsor links, and just clicked to see if there’s any on a random project, nope. From a cursory look at [Stefan]’s project list, like, damn, go check it out, such a flurry of projects is par for the course for [Stefan], and I have to admit that I dig it. Each project is a complete publication, there’s a hundred+ of them, and having clicked on a few more, didn’t see any links or other bullshit – a description, a beautiful photo, followed by an EasyEDA and a GitHub link in the sidebar; every single project is completed as far as I can see, did I mention that there’s over a hundred? This guy could easily get an ongoing sponsorship from some PCB fab given the project quality, and now that you bring it up, I’m surprised that he hasn’t, I’ve gotten sponsorship offers for less.

      Which brings me to a personal opinion of mine, based on something I’ve noticed – I think it’s pretty nice that hackers can get sponsorships from PCB houses and such, as from what I’ve seen, the “sponsorship” ecosystem can, for instance, help less-well-funded hackers bring their projects to everyone’s attention despite budget shortcomings, or push more well funded hackers towards finally getting some PCBs made. If a project is notable for Hackaday, sponsorship or not, then we’ll cover it; if it’s not up to snuff, then it doesn’t grace our pages; but, damn, it sure is nice that, say, an up-and-coming low-budget hacker can have more of a chance to compete with the “maker with a well-paying job” demographic.

      Here’s an example – we cover a worthy project from someone who got it made with help of a PCB sponsorship, whether they’re low-budget or medium-budget, idc, they had a reason to take up the offer, even if it’s “oh cool, some motivation to finish that old board of mine”. Our coverage, then, is a) a boost of confidence for the hacker, b) promotion for the hacker, which wouldn’t be there if it weren’t for the PCB house, and c) leverage for the hacker to get further sponsorships. All three of these mean we can get more hacks from a now-more-experienced hacker in the future – and again, if those look coverage-worthy and [insert a hundred other factors that can determine whether a project gets covered], that’s more hacks for our audience to witness.

      Thoughtdump over – hope you enjoyed this article’s worth of thoughts!

      1. (Note up front – this comment is not about [Stefan])

        I think that disclosing any sponsorship or affiliation (if there is one) is the important part. If Adafruit posts a project that uses their products, the affiliation is obvious. If [random_hacker_123] posts a project and is sponsored by the company who’s parts are used, that should be disclosed.

      2. I totally agree here. The chip maker themselves could have done all of these projects purely for hype and marketing, and it would still be worth an article, because it makes the chip way more useful, and it’s a solid selection of open source hardware and software for people to hack around with. If they sponsored someone else to provide such great valuable to their customers, great, they totally deserve the attention. And even if someone just did the projects because the chip is well suited to that application, the chip maker still deserves the attention, because the chips themselves carry significant value. The important part isn’t whether someone got paid off to do the projects. The important part is the value the projects and the chip provide to the rest of us. If the chip maker paid someone to do the work to provide use with that value, kudos to them. If they didn’t but the chip turned out to be a good candidate, kudos to them for designing a good project. It’s hardly relevant beyond that though. I care about the value provided to me and others like me more than the gritty details of whether someone got paid to produce that value or not.

        Anyhow, thanks for the article! That’s absolutely fascinating. It also makes me realize that maybe some of these trivial projects I’ve done to fill some trivial need might be worth publishing under an open source license! (For example, I’ve written autoclicker programs for the Teensy, the QT Py RP2024, and the NeoKey Trinkey, mainly for use in video games. The NeoKey Trinkey one is mildly advanced even, mainly because it has a single touch input, that I had to use for changing between several modes.)

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