Low Tech Wind Speedometer

Hi everyone! This is a very low tech speedometer The way the speedometer works is the harder you blow, the more LEDs light up.

1. 4 LEDs (done most easily with 4 different colors, but I do this tutorial with just two different colors)
2. Motor (I used the small motor that comes in the Bambu Labs Maker's Beginner Kit)
3. Wires
4. Breadboard
5. Multimeter

Put the two probes of the multimeter to different terminals of the motor and set the multimeter to measure voltage. Spin the motor as fast as you can by hand (I snapped my fingers to get it to spin fast), and if it reaches around 1 volt it will work. Too little and you will have to bike super fast for them to turn on and vise versa with too high.

If you are using the same Bambu Labs motor as me, I printed this propeller from MakerWord. If you have a different one, the easiest way to make a propeller is to open up Tinkercad, search for propeller in the Shapes Library and add a hole using a cylinder. (shown in the first image)

Attach wires to the terminals of the motor as shown in the second image.

To figure out which side of the motor is positive, attach an LED as shown in the first image and blow on the motor. If the LED doesn't turn on, switch which rail the motor's terminal wires go to and try again. This should put the positive terminal on the marked positive rail on the breadboard.

If you have 4 different colored LEDs, arrange them in order from lowest to highest forward voltage. The order from lowest to highest is Red, Orange, Yellow, Green, Blue, Violet, White.

If you don't have 4 different colored LEDs like me, copy the arrangement of the breadboard in the second photo. Slowly blow on the propeller and take note of which LEDs turn on first. Shuffle their order on the breadboard until they're in an order where they generally turn on one after the other.

Use three resistors to connect the positive sides of the LEDs together. Use the fourth to put a resistor between the motor's positive line to the first LED. This is shown in the third image.

Your speedometer is finished! Blow on the propeller and see how many LEDs you can light up.