I have a wheel with a hall sensor to count rpm.
I need a switch/control so that I can input the #of rotation I want the wheel to do.

If input 4...... The wheel will rotate 4 times.
Counting the halls sensors inputs on each rotation until reaching the input #


I was going to program an Arduino to do this but I have a feeling that there is an existing off the shelf component that will achieve my goals with less complication/work.

Thanks I hope someone picks up what I'm putting down.

 

You want a programmable count up to N and halt, then do something, in which N is whatever number of revolutions you want. Commonly called a Totalizer / Rate meter as they can display a rate such as RPM or a total count increment up for each rotation. A simple example would be an OMEGA DPF 701. The link is merely an example, I would guess there are plenty of inexpensive Chinese versions to be had.

Units like this are popular on, for example, coil winding machines. You make no mention of your sensor signal levels or how many pulses per revolution or a few other variables like what you want the output to be but you can get the general idea from the link.

Ron

 

Thanks Ron For the reply. I'm making...... Picture a slow motion motorized yo-yo. The yo-yo or wheel is 4" round making the circumference close to 12". I'm placing 2hall sensors 180° from Each other at 12 and 6 o'clock.
I have an Arduino as the "brain" to count the revs but haven't had time to get into the programming(newby).
But I figured there had to be some component that accomplish the task cheaply all g with cutting out the Arduino.
I'm picturing, like you link, something with a digital display and an up/dwn button for yoyo length selection. 1,2,3,4,
Then when it counts its way up to the selected # it then acts as a switch sending a signal to a dpdt switch to reverse the yo-yo . N so on. N so on.
Thanks again,
Mark

 

Knowing that I would look for a cheap programmable counter, again count to N. I would have used a simple DC motor driven by an H Bridge, the H Bridge is your DPDT switch to reverse the motor which would reverse the direction (rotation). What happens is as the motor rotates each revolution gives you about 12" of travel on your string. When you count 4 revolutions, depending on pulses per revolution, the motor will be reversed.

You could use an Arduino or any of several micro controllers with a few binary switches on the digital inputs to set N. I have never done it but it seems very doable. You could also just roll your own using components but actually using a micro controller is likely the easier route. Finally an off the shelf solution similar to what I linked to.

Ron

 

There is likely no one component that would satisfy your requirement. But you could roll your own with a couple of counter chips (adding reset circuitry and possibly up/down control circuitry) that are daisy chained and a few resistors. Then, you’d have to add input circuitry to enter the desired number of rotations, possibly with BCD thumbwheel switches and a few more resistors plus chips for BCD to binary conversion. Followed by comparison circuitry to determine when the count equals the desired revolutions. A few AND gates plus a handful more of resistors.

Or if you know how to program, use a microprocessor, your hall sensors, a couple of BCD thumbwheel switches and a MOSFET plus a couple of resistors.

 

All very helpful suggestions. I think I'm gonna go the Arduino or microprocessor. This way I will have the ability to make the project have Wi-Fi capability.

Next I think I'm going to try and find some good electronics groups that I can apprentice with and possibly partner with on my project.
I'm from south Chicagoland. Anyone know any good groups or people in the area of Chicago, IL?

Yes, in order to get this project back up and moving I am going to need to partner with someone on this idea.
Thanks

 

One of the easier ways to do this these days is with an
ESP8266 or ESP32 (the WiFi capability portion) along
with its A/D and other capabilities.

There are example projects (after you add the libraries) in Arduino
which will allow you to get up and running on WiFi in a matter of
minutes, and you add code to do the counting and other tasks.

https://www.espressif.com/en/products/hardware/esp8266ex/overview

https://en.wikipedia.org/wiki/ESP8266

https://www.esp8266.com/

https://github.com/esp8266/Arduino


https://www.espressif.com/en/products/hardware/esp32/overview


Tons of projects on web, youtube.... https://hackaday.com/tag/esp8266/


Regards, Dana.