I recently got hold of some Hard Disk brushless motors, and want to use them to control my PC volume. How can I achieve that?
You need to break the project down into its parts:
Read input from the motor with the Arduino board..
Send volume control commands from the Arduino board to the PC.
PC application that receives the volume control commands and changes the volume accordingly.
I would start by deciding what you will do for the PC application, and how the communication between the Arduino board and the PC will be done (e.g., serial over USB, Bluetooth, WiFi, Ethernet).
The next step is to wire your motor up to the Arduino and verify that you are getting input from it. For this, just write a simple sketch that reads the input and prints to the Serial Monitor.
HarryB123:
I recently got hold of some Hard Disk brushless motors, and want to use them to control my PC volume.
Eh? 
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html .
Can you explain how a HDD motor will control the PC volume?
Thanks.. Tom.... 
Paul__B:
Eh?
A HDD motor has 3 pairs of coils, 120° out of phase. If you turn the motor, you'll induce sinusoidal voltages in these coils. Connecting two of them to a comparator/opamp results in two square waves, 120° out of phase, which can be used like the signals from a quadrature encoder.
Pieter
PieterP:
A HDD motor has 3 pairs of coils, 120° out of phase. If you turn the motor, you'll induce sinusoidal voltages in these coils. Connecting two of them to a comparator/opamp results in two square waves, 120° out of phase, which can be used like the signals from a quadrature encoder.Pieter
A really convoluted way to make an encoder that can be bought for a dollar...
I think the OP wants to rotate a potentiometer with an HDD motor (ROFLMAO!!!)
The “premium feel” (I know, I’m crazy) of the motor feels nice, so I want to make it into a pc volume control
How can I do this?
I do not understand the code in the description
Could you not have posted that link earlier? Looks like Pert and PieterP were on the right track.
You will need to download the Arduino code from that youtube page, compile it using the Arduino IDE and upload to an Arduino.
2)
You will need to install Visual Studio on the PC and download the VB.net code from that youtube page and compile it. Next you can run it.
If you don't understand, you will have to explain what you don't understand; please note that this is an Arduino forum so help with VB.net code might be limited.
Hi,
just a heads up for anyone new to electronics who might follow this...
watching that video and looking at the circuit diagram, where all of the 'lines' cross, it couldn't be more complex if they tried to make it so.
By simply rearranging 'L1' - 'L3' and 'N' into reverse order no line would cross any other.
One of the things that annoys me slightly...looking at that diagram it seems like whoever drew it simply doesn't care about things like 'ongoing maintenance'.
Where they, or anyone else, might need to look at it in a few years time to try to figure out how it works and it would be so easy to miss-understand it as it's a poor drawing.
Peter
Peterd51:
Hi,just a heads up for anyone new to electronics who might follow this...
watching that video and looking at the circuit diagram, where all of the 'lines' cross, it couldn't be more complex if they tried to make it so.
By simply rearranging 'L1' - 'L3' and 'N' into reverse order no line would cross any other.
One of the things that annoys me slightly...looking at that diagram it seems like whoever drew it simply doesn't care about things like 'ongoing maintenance'.
Where they, or anyone else, might need to look at it in a few years time to try to figure out how it works and it would be so easy to miss-understand it as it's a poor drawing.
Peter
I really don't see how this can work.
The voltage output of the HDD motor will be proportional to the speed that it's rotated. There could be a range from millivolts to 10's of volts.
To even hope to make this work a rather high gain circuit to read the slow rotation and a clipper or limiter to prevent over voltage would be necessary.
What is wrong with using the right part for the job... an encoder? They can be had with or without detents, low or "high" torque... i.e. any feel the user desires.
The insistence on using a 3 phase motor as an encoder completely baffles me.
krupski:
The insistence on using a 3 phase motor as an encoder completely baffles me.
Ah, but this is after all, "Project Guidance" on the Arduino forum. 