All the USB you can do with a CH552

Recently you may have noticed a slew of CH552 projects on Hackaday.io - all with professionally taken photos of carefully assembled circuit boards, usually with one or two USB connectors. You might also have noticed that they're all built by one person, [Stefan "wagiminator" Wagner], who is a prolific hacker - his Hackaday.io page lists over a hundred projects, most of them proudly branded "Ended". Today, with all these CH552 mentions in Hackaday.io's "Newest" category, we decided to take a look.

The CH552 is an 8-bit MCU with a USB device, with a sibling CH554 supporting USB host, and [Stefan] is putting this microcontroller to the test seriously. There's an nRF24L01+ transceiver turned into a USB dongle, a rotary encoder peripheral with a 3D printed case and button, a mouse wiggler, an interface for our beloved I2C OLED displays, a development board general purpose CH55x and a burst of regular AVR - AVRISP programmers, an ISP+UPDI programmer and an UPDI programmer with HV support. Also, if you are interested in USB host, there is a CH554 USB host development board specifically. Each of them is open-source, with PCBs designed in EasyEDA, firmware already written (!) and available on GitHub, and a carefully designed documentation page for each.

[Stefan] put the CH552 through its paces in earnest, 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, especially more than the CH552 and CH554 cost around 50 cents a piece on websites like LCSC, and mostly in user-friendly packages. We covered both of these chips in 2018, with a programming guide, and we've seen things like badges built with his help, but having all of these devices to keep up with is an increase in availability - plus there's no denying that all of the built widgets are quite useful on their own!