0

Speed controlled RPM matching LED strip

20170804 163539 PIjU3kvy8V

Nice project + write-up from Latch Hristov up on Hackster.io.

After fumbling for some time with double-clutch heel-toe juggling, I decided I could help myself with a microcontroller. It starts with an IR sensor in the speedometer.

If you don’t know how an old speedometer works – a metal drum spins around a permanent magnet (could be more than one) spring loaded and connected to the speed needle. The induced magnetic field (current, actually – Lenz’s law) in the drum has polarity that opposes that of the magnet and subsequently, as the drum spins, it also applies a force on the magnet displacing the speed needle. The faster the drum spins, the greater the field disparity, the greater the force, and subsequently the deflection of the needle. Some energy is lost to the eddy currents, but overall it’s a clever system. Anyway – it’s the spinning drum which is moved by a cable connected to the differential of the car that is useful in this case. As it spins, the purple nail-polish stripes block (an then unblock) the reflection from and IR LED. A photodiode, then picks up this timing.

Read more.


Join 7,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython in 2018 – Python on Microcontrollers is here!

Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/


Maker Business — The many, many manufacturing processes listed on Wikipedia

Wearables — A bevel illusion

Electronics — Blown transistor?

Biohacking — We are Wired to Exercise at a Moderate Pace

Python for Microcontrollers — Make It Move with Crickit!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



No Comments

No comments yet.

Sorry, the comment form is closed at this time.