The peak of the popularity of spinners came in 2017. Manufacturers and sellers understood that hype would end soon and as suddenly as it had begun. Sellers stood in crowded places almost every fifteen to twenty meters - and it seemed that they did not compete with each other at all. There were enough buyers for everyone. Then the author of Instructables under the nickname NagyD1 invented and manufactured do it yourself for spinner tachometer. It can be used to measure spinner revolutions per minute.-1, linear speed in m / s or km / h, period in ms. Today, when the spinner, due to the complete end of the hype, is quite inexpensive, but it still lingers on the store shelf for a long time, such homemade It’s also interesting to repeat. In the tachometer firmware, the spinner has three blades. If there are two blades, the sketch will have to be redone a little. Also, in any case, it will have to indicate the diameter of the spinner. And to seal the holes in the bearings located in the blades for weight gain.
Together with Arduino the wizard applies components from the “Sensors, 37 in one” kit: modules with a laser and a photoresistor. To display the results, a 4-bit LED display with a common cathode is provided, it is optional, since you can redirect data to a computer in the Arduino IDE serial port monitor.
The master attaches corners to the base, to one of which glues the module with a laser, to the other - with a photoresistor so that they are directed towards each other. All the rest electronics he places right on the ground.
Seals holes in spinners (see above):
Connects the photoresistor to input A0 Arduino, the button - to input A1. Pulls both up 10-kilo-ohm resistors. Connects the display like this:
1 - to the conclusion of the Arduino D2
2 - to the conclusion of the Arduino D6
3 - to the conclusion of the Arduino D11
4 - to the conclusion of the Arduino D3
5 - to the conclusion of the Arduino D4
6 - to conclusion Arduino D7
7 - to the conclusion of the Arduino D10
8 - to the conclusion of the Arduino D9
9 - to the conclusion of the Arduino D13
10 - to the conclusion of the Arduino D8
11 - to the conclusion of the Arduino D12
12 - to the conclusion of the Arduino D5
Makes up sketch, in which, before pouring, it is necessary to correct the diameter of the spinner and the number of blades in it. If there is no display, redirect data output to the serial port monitor. If desired, organize the display of a different type.
After filling in the sketch, the master tests the device. Modes are switched by a button on the ring. There are four of them: speed, period, linear speed in m / s, it is in km / h. When the spinner is stopped or absent, the display shows the name of the mode: respectively, FFFF, 7777 or SSSS. For some reason, programmers around the world, when working with four-digit displays, think the same way: how about AAAA? In both modes of linear velocity measurement, the name is the same, the readings differ by 3.6 times.
And Exupery is right: adults really love numbers. Even when spinners spin.