5 ms·

According to a comment on the parent article, all USB keyboards receive the standard 3 lock keys so they can toggle state (think LED lights): Caps Lock, Num Loc

According to a comment on the parent article, all USB keyboards receive the standard 3 lock keys so they can toggle state (think LED lights): Caps Lock, Num Lock, Scroll Lock If true, this is why the author chose to use Caps Lock over a different key. I can't claim whether that is true or not but it puts a damper on the USB keyboard security concerns.

zbanks 16y ago
You are correct. There are a few other small triggers that the keyboard can also potentially receive, but those 3 are the most common. HID in general can be set up to receive more data, but there aren't any "normal" devices with built-in drivers that utilize a lot of bi-directional data transfer. (I've been looking to create a "driverless" "serial port" using HID communication, tx is easy (keyboard type), but rx is hard (bitbanging using the 3 LEDs? eh....)
- follower 16y ago
  > I've been looking to create a "driverless" "serial port" using HID communication When you say "driverless" do you want it to act as an actual serial port or just provide bi-directional data transfer for a userland program? I think there's a standard V-USB example that provides driver-less bi-directional data transfer via reports. I adapted the example to work with the Arduino and a Python script. Some details are in the entry dated 22 October 2009 here: http://code.rancidbacon.com/ProjectLogArduinoUSB http://code.rancidbacon.com/ProjectLogArduinoUSB The code is online as the UsbStream example available in the download from here: http://code.google.com/p/vusb-for-arduino/downloads/list http://code.google.com/p/vusb-for-arduino/downloads/list