If you ever get bored of trolling the internet seeking inspiration for your next big project, try a YouTube search of “useless machine”. After a few hours of watching these pointless, yet hilarious creations, we’re sure you’re going to want to build one. Luckily for us, [Arvid] documented the design of his moody useless machine to get you started.
Why is [Arvid's] machine moody? Well, to fully appreciate the emotional sensitivity of a useless machine, you first need to understand what it is they do don’t do. A one sentence explanation is all that is needed here; you flip a switch and the machine flips the switch back… that’s it. [Arvid] implemented a two servo system with a stand-alone Arduino, which allowed him to give his machine a “personality”. Sometimes the switch is thrown back quickly without argument, other times the machine throws a fussy tantrum.
Although the machine is useless, the electronics inside are anything but. To keep everything clean and innocuous looking, the machine is powered by batteries, so [Arvid] places the Arduino into a ‘sleep’ mode until the switch is toggled. The switch is configured as an interrupt on the Arduino, which when toggled, wakes the Arduino. Once the Arduino is awake, it enables power to the servos via a power MOSFET, then everything’s ready to go; the machine makes its response and goes back to ‘sleep’. This was a great project, but believe it or not, things can get more useless, like with this advanced useless machine.