Source: Compiled and connected a mouse/keyboard firmware running on an ATtiny861a using internal RC oscillator.
Hell, Atmel even sells Cortex-M chips with High Speed USB-2 support (reasonably hard to find; most are only Full Speed).
I've been doing embedded systems large and small for decades but before this year, never put anything with an ARM into production.
AVRs are still my go to for most things because I know them well and have all the tooling ready to go.
[R]ecent update to the Raspberry Pi 4 bootloader
(...) enables data over the USB-C port
No, all the power delivery negotiation in USB-C, both the basic one using only passive resistor values and the advanced one using the USB-PD protocol, is through the configuration channel pins, which is a separate pair of pins completely independent from the USB 2.0 pins in the middle. (The configuration channel is implemented incorrectly on the Raspberry Pi 4, however; it shorts together the pins, while they should be separate, so it fails with advanced cables which use both pins; and when powered through a source other than the USB-C connector, it incorrectly sources 5V to the USB-C port even when it shouldn't.)
https://www.raspberrypi.org/documentation/hardware/raspberry...
A new revision is underway, a fix is just using dumb cables.
That is, the workaround is both "use only dumb cables (which use only one of the CC pins)" and "never connect to a USB-C device which might source power while the rpi is being powered by something other than the USB-C".
Wouldn't this actually apply to a lot of use-cases of the project in the linked blog?
The whole point is connecting the RPi as a peripheral of a laptop, i.e. a power-sourcing host. if you do that, you'll also likely be tempted to use an external power supply for the Pi as the USB's supply is limited. It's important to note that this will lead to problems.
... build a safe password keeper that looks like a HID device
... do something interesting with USB-based gamepads to map those to keyboard keys for playing old DOS games
... make a connected USB storage device that offers some sort of additional sync services for the data stored on it (maybe over wifi?)
... make a network adapter that also acts as a firewall, or possibly links to tor/vpn/etc
... Something something MIDI over USB
There used to be a KS funded case built around a Pi and an HDD that would act as an external storage when plugged to a USB port and would work as Kodi based media player once booted and connected to an HDMI port.
If anybody knows if this can be done DIY style with minimal cable mess I am all ear :).
edit: ah ! https://geekworm.com/blogs/raspberry-pi/how-to-add-extra-sto...
There’s an Android app for that, it’s one of the biggest things I miss after switching to the iPhone.
There are a few of those around.
Does anyone know if any such similar devices are already available? Whether based on an RPi or not?
You want to run a secure off line personal Certificate Authority (a Pi Zero would probably be enough and can work in the same way)
It can also be any other type of USB device, e.g. a HID device (keyboard/mouse/joystick) you can dream up loads of interesting things to do with this