Arduino program and hardware for rapidly typing characters using a Pro Micro - 5V/16MHz as a USB Human Interface Device (HID) keyboard. Based on Turn your Pro Micro into a USB Keyboard/Mouse. The device has been tested and works on Linux, Mac and Windows.
I built this to aid in debugging a textarea in a web page which was intermittently dropping characters in IE11 due to a Javascript issue.
When manually typing at the keyboard, it's hard to tell if intermittent character loss is due to a bug, or because the keys were not pressed properly. In addition manual typing speed is limited, so its not possible to do 'stress' testing. This device solves both these problems by emulating a USB keyboard and generating characters programmatically.
There are three adjustable parameters available via the buttons:
- Lines - the number of lines of text to output (-1, 1, 2, 4). The default is -1 (unlimited).
- Characters - the number of characters in each line (5, 13, 26, 52, 104). The default is 26 (a-z).
- Rate - the rate of character generation in characters/minute (100, 200, 400, 1000, 6000). The default is 200 (average typist). 100 is a slow typist, 400 is a professional typist and anything higher is not humanly possible!
These parameters may be adjusted while characters are being generated. Character generation is started and stopped with the toggle switch. A video of the device in action is here.
This is the schematic for the project. If the schematic appears to be missing details, download it and view it locally, or zoom the web page.
The code in repository has the configuration files to allow it to be imported into the PlatformIO development environment, alternatively it may be edited in the Arduino IDE.