Sometimes a device is just too tempting to be left untouched. For
[Neutrino], it was an old Casio calculator that happened to have a
perfectly sized solar panel to fit a 128×32 OLED as replacement.
But
since the display won’t do much on its own, he decided to connect it to
an ESP8266 and mount it all inside the calculator’s housing, turning it into a spy-worthy, internet-connected cheating device, including a stealthy user interface controlled by magnets instead of physical buttons. more
It wouldn't take much to turn this into a Wi-Fi bug.
