Wiping Your Windscreen To The Beat

Nothing spoils your mood quite like your windscreen wipers not feeling it when the beat drops. Every major car manufacturer is focused on trying to build the electric self driving vehicle for the masses, yet ignoring this very real problem. Well [Ian Charnas] is taking charge, and has successfully slaved his car’s wipers to beat of its stereo.

Starting with the basics, [Ian] first needed to control the speed of the wiper motor. This was done using a custom power supply adapted from another project. The brain of the system is a Raspberry Pi 3B+ which runs a phase locked loop algorithm to sync the music and the motor. Detecting the beat turned out to be the most difficult part of the project, and from the research [Ian] did, there is no standard solution. He ended up settling on “madmom“, a Python audio and music signal processing library, which runs a neural net to detect the beat in real time. The Raspi sends the required PWM and Enable signals to an Arduino over serial, which in turn controls the power supply. The entire system was neatly integrated in the car, with a switch in the dash that connects the motor to the new power supply on demand, to allow the wipers to still be used normally (and safely).

[Ian] filed a provisional patent application for the idea, and will be putting it on auction on eBay soon, with the hope that some major car manufacturer would be interested. For older cars, you can shove an Arduino into the stereo, or do a super cheap bluetooth upgrade. Check out the video after the break.

31 thoughts on “Wiping Your Windscreen To The Beat

  1. LONG AGO WHEN i WAS INSTALLING CAR RADIOS it was typical to snoop around and find a hot lead that switched with the battery and use that for the supply to the small Motorola $29.95 radio. In some European cars it was the custom to place the power switch in the ground side of various circuits. A cute girl with a Renault wanted a radio next day she said when I turn the radio way up my wipers wiggle. Radio was powered thru the wiper motor. Everything old is new again..

    1. Ha. What a terrible place to hook up power. Can’t blame them though, it happens when you have a bunch of quick turnarounds I guess. Not to mention there’s probably lots of inductive spikes with little to absorb them before they feed into the radio, but I suppose those have some kind of regulation circuitry inside them. It would need it to iron out the transients that are already native to a car electrical system. But with cheap hardware you never know.

      This could be some unintended consequence of getting rid of car cigarette lighters. Always been one in the dashboard when I’ve put in a radio under a shade tree. Or are those typically unswitched on most cars? I tested on mine that it went cold when the ignition was turned off. But I dunno if that’s the rule.

      1. There is no rule :-) I have seen both versions.
        And although it’s technically no cigarette lighter socket (no bimetallic strip to hold and eject the lighter element), I have a 12V socket, which is of even increasing importance when you think just for a second on our modern power hungry mobile devices.

  2. Ha I love this because here is somebody who actually acted on an inkling of dissatisfaction I think nearly everybody with a car has. Most of us have been there when the wipers are juuuust almost on the right BPM but then you gotta slowly watch them drift out of phase and then wait for them to come back to the beat. It’s one of those little pointless moments that a ton of people have in common but don’t really mention.

  3. I have this car, as cute as that is, can you please hack it so the windscreen wiper actually works and doesn’t leave a streak down the passengers side or that squared of tick above the driver that ends up running down the window so you have to flick it again.

    1. Bidding on a provisional filed by an amateur is a pretty dicey proposition. Who knows how well he wrote it? And the priority date for the provisional is only valid for things that he actually set out in the specification. I have filed some patent apps on my own, and one of them was actually granted recently. I’m also on maybe 30 patents through my employer. Every time a patent is finally granted, I look back at it in alarm because I’ve learned so much in the intervening years that I SHOULD have listed in the specification but didn’t know at the time. I guess that’s why you build IP portfolios.

      I see it’s up to $358 right now. I wish the bidder good luck.

    1. Yup, looks that way. But let’s be honest, the examiner would have to find that hackaday article which is not in the patent database or otherwise someone would have to contest the application. both are unlikely. Afterwards if this patent was granted it would have to be worth the 100k for someone to challenge the patent based on prior art which is also unlikely. So I would venture whoever buys the provisional, could get a patent granted but would expect lots of infringement which is the point of the patent to begin with…. in all cases we enjoy music synced wipers and the lawyers win while companies sue and get sued.

  4. Give a real test and cue up the river dance sound track. Whatever the beat is it’s going to be annoying if it’s out of step intense lighting strobing the wipers at night. My uncle was working on his bosses’ first gen, Firbirad an was having trouble sorting out the windshield wipers. He handed me the schematic for help. I looked at it, and told him no wonder he was confused. The switch was switching the negative side, not the positive

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