Like some of our grouchier readers, [PodeCoet]’s Digital Sub-Systems professor loathes everyone strapping an Arduino onto a project when something less powerful and ten times as complicated will do. One student asked if they could just replace the whole breadboarded “up counter” circuit mess with an Arduino, but, since the class is centered around basic logic gates the prof shot him down. Undeterred, our troll smuggled an MCU into a chip and used it to spell out crude messages.
No Arduino? No problem. It took him 4 tries but [PodeCoet] hollowed out the SN74LS47N display driver from the required circuit and made it the puppet of a PIC16F1503 controller. The PIC emulated the driver chip in every way – as ordered it showed the count up and down – except when left unattended for 15 seconds. Then instead of digits the PIC writes out “HELLO”, followed by three things normally covered by swimsuits and lastly a bodily function.
For such a simple hack it is wonderfully and humorously documented. There are annotated progress/failure pictures and video of the hack working.
It is not as elaborate as the microscopic deception in the infamously impossible 3 LED circuit, but it gets to the point sooner.