The end result is a USB stack running on the ESP8266 WiFI module. [cnlohr] has been working for about a month on this USB implementation for the ESP, beginning with a logic analyzer, Wireshark ...

While RAM often ends up scarce on an ESP8266 with around 40 kB or so ... power measuring unit to the devices under test, a USB cable with three 3 Ω resistors and an oscilloscope.