Published August 23, 2019 © GPL3+

Ahmsville Dial

This is an Arduino-based dial controller, inspired by Microsoft’s surface dial. (A secondary controller for you PC.)

IntermediateFull instructions provided2 hours3,051

Things used in this project

Hardware components

Arduino pro micro (ss micro)

Ahmsville dial kit

Individually addressable led

6906 Bearing

3x1 neodymium magnets (30 pcs)

8mm rubber base pads

usb cable (thickness <3.5mm)

(salvaged from an old mouse)

m3 x 8 self tapping screws (6 pcs)

(Salvaged)

Thin flexible wires

Salvaged

Hand tools and fabrication machines

3D Printer (generic)

Soldering iron (generic)

Multitool, Screwdriver

Super Glue

Story

Like many other hackers / content creators, I use a lot of design applications, from cad applications, pcb design applications, to graphics design applications like photoshop and premier pro. A mouse and a keyboard; while often sufficient for interacting with this application, cannot compare to the convenience of having a dedicated dial controller for zooming, scrolling and tuning type operations.

Mind you, the dial’s functions are not limited to application specific controls, I personally use it as my dedicated media controller, as a color-based passkey to login to my PC, and also as a macro key device for running quick operations on my PC.

The dial uses the ATmega32U4, a chip capable of emulating keystrokes and mouse controls, its the same chip found on the arduino pro micro. As the dial is arduino based, programming it to suit your needs is really easy, especially with the dedicated library I’ve written for it.

The Design

Even though this is a DIY project, the dial is designed for longevity, this is not a device that will ever fail, at least not physically; I made sure of it, by using magnetic rotary encoding instead of the more common contact based rotary encoders; the use of capacitive touch instead of push buttons is also another choice I made to ensure that the dial is robust.

The dial’s enclosure is 3D-printed, and can be printed in a number of way, with a variety of materials and in a number of colors; as is common with 3D-printed thing in general.

Achieved with a little calculated filament swapping

Dial Features:

Magnetic rotary encoding (for contactless and smooth knob rotation).
Capacitive touch top (detects four touch types - single and double tap, short and long press).
Programmable LEDs and vibration feedback.

The Knob (Magnetic Rotary Encoder)

The knob has magnets with alternating poles attached to it, and the hall effect sensors on the dial board are used to read the analog value changes that occurs when the knob rotates. With this setup the circuit/sensors is completely isolated; it makes no physical contact with the knob, hence the contactless and smooth rotation. This magnetic rotary encoding method is also highly scalable, in terms of size and resolution. You can learn more about it here- https://github.com/ahmsville/Magnetic_rotary_encoding

Capacitive Touch Inputs

Under the knob lies a capacitive touch pad that gives you four touch inputs, single tap, double tap, short press and long press, this touch inputs can be mapped to different functions on your PC. The capacitive touch detection is also done on the Arduino, you can learn more about it here- https://github.com/ahmsville/Advanced_capacitive_touch_detection

Programmable LEDs and Haptic Feedback

The dial uses the traditional addressable LEDs, they are strategically placed to provide the dial with functional aesthetics, so in addition to making the dial look really cool, they also provide additional functionalities to the dial. For example: programming application specific keystrokes for multiple applications by simply assigning different colors to each application, the aforementioned color-based passkey is also another example…watch the full Video to learn more.

The Dial also uses a micro vibration motor to provide a really satisfying haptic feedback for the knob’s rotation and the capacitive touch inputs.

Circuit & Parts

Schematic.

Parts required to make the dial.

Arduino Pro Micro (ss micro) - https://ebay.to/2H8KfTF
Ahmsville Dial kit - http://bit.ly/tindie_ahmsville-dial
Individually addressable LEDs - https://ebay.to/30jeUWg
6906 Bearing - https://ebay.to/2KPDIOR
3x1 neodymium magnets (30 pcs) - https://ebay.to/31Mot0a
8mm rubber base pads - https://ebay.to/33FN6NF
usb cable (thickness 3.5mm) - (salvaged from an old mouse)
m3 self tapping screws (6 pcs) - (salvaged)
Thin flexible wires. - (salvaged)

Download Full Build Instructions

Schematics

Code

Sample code

#include <Ahmsville_dial.h>
#include <FastLED.h>

/*
    upload sketch to the dial to test all its functions.
    ....By Ahmsville...
*/


Ahmsville_dial ahmsville_dial = Ahmsville_dial(); //create a new ahmsville dial instance

/********************************************************************LED CONFIGURATION*****************************************************/
#define DATA_PIN    10
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB
#define NUM_LEDS    4
CRGB leds[NUM_LEDS];

#define BRIGHTNESS         127

uint8_t gHue = 0; // rotating "base color"
int count = 0, touch;

void setup() {
 ahmsville_dial.initialize_ahmsvilleDial(1);   //initialize ahmsville dial
  initializeLED();
}

void loop() {
  rainbow();  // LED animation
  count += ahmsville_dial.knob();  //detecting knob rotations (returns a signed integer in relation to the direction of the rotation)
  touch = ahmsville_dial.capTouch();  //detecting capacitive touch (returns integer 1 - 4 or 0 when no touch is detected)
  Serial.print(count);  //print knob rotation count
  Serial.print("\t");
  if (touch == 1) {  //print "singletap" if touch type is 1
    Serial.println("singletap");
    delay(1000);
  }
  else if (touch == 2) { //print "doubletap" if touch type is 2
    Serial.println("doubletap");
    delay(1000);
  }
  else if (touch == 3) {  //print "shortpress" if touch type is 3
    Serial.println("shortpress");
    delay(1000);
  }
  else if (touch == 4) { //print "longpress" if touch type is 4
    Serial.println("longpress");
    delay(1000);
  }
  else if (touch == 0) { //print "no input" if touch type is 0
    Serial.println("No input");
  }
  ahmsville_dial.normalize(1);

}

/********************************************************************LED SETTINGS/ANIMATION*************************************************/

void initializeLED() {
  // tell FastLED about the LED strip configuration
  FastLED.addLeds<LED_TYPE, DATA_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);
  // set master brightness control
  FastLED.setBrightness(BRIGHTNESS);
}

void rainbow() {
  EVERY_N_MILLISECONDS( 20 ) {  //frames/milliseconds delay
    // FastLED's built-in rainbow generator
    fill_rainbow( leds, NUM_LEDS, gHue, 10);
    // send the 'leds' array out to the actual LED strip
    FastLED.show();
  }
  EVERY_N_MILLISECONDS( 30 ) {
    gHue++;  // slowly cycle the "base color" through the rainbow
  }
}

Credits

Ahmed Oyenuga

6 projects • 22 followers

I am a Hardware Engineer, I enjoy exploring creative technology solutions, and building accessible design and engineering tools.

Ahmsville Dial

Things used in this project

Hardware components

Hand tools and fabrication machines

Story

The Design

Dial Features:

The Knob (Magnetic Rotary Encoder)

Capacitive Touch Inputs

Programmable LEDs and Haptic Feedback

Custom parts and enclosures

base (reg vibration motor)

Board holder

Led diffuser

Build Instructions

STL files

Knob

base (coin vibration motor)

Schematics

Schematic

Code

Sample code

Magnetic rotation encoding

Ahmsville Dial

Capacitive touch detection

Arduino Capacitive sensor library.

FastLED

Credits

Ahmed Oyenuga

Comments

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Ahmsville Dial

Ahmsville Dial

Things used in this project

Hardware components

Hand tools and fabrication machines

Story

The Design

Dial Features:

The Knob (Magnetic Rotary Encoder)

Capacitive Touch Inputs

Programmable LEDs and Haptic Feedback

Custom parts and enclosures

base (reg vibration motor)

Board holder

Led diffuser

Build Instructions

STL files

Knob

base (coin vibration motor)

Schematics

Schematic

Code

Sample code

Magnetic rotation encoding

Ahmsville Dial

Capacitive touch detection

Arduino Capacitive sensor library.

FastLED

Credits

Ahmed Oyenuga

Comments

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