#jogwheel

It's so great!

Design for a DIY jog wheel, using optical sensors. Most interesting is the mechanical assembly of the whole thing.

Added the correct capacitors (see diagram below, P9 of the datasheet) for running the AS5048A at 3.3V, which may have made it a little smoother. I was able to pull back the filter range to 3 without getting any noticeable noise. You can still hear the steps at low speeds but should be good enough for fast scratching and jogging.

I also adjusted the pwm_min and pwm_max values from 0 - 1000 to 3 - 910, because in the serial debug I have never seen values outside those limits. This eliminated the ‘jump’ that could be heard in the first video using Virtual DJ as the values cross the 0/max point.

Final code (AS5048_PWM_simpleMIDI04):

//http://www.benripley.com/diy/arduino/three-ways-to-read-a-pwm-signal-with-arduino/ #include <C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\MIDI\MIDI.h> #include <midi_Defs.h> #include <midi_Message.h> #include <midi_Namespace.h> #include <midi_Settings.h>

int pwm_value; //current pwm reading int pwm_prev; //previous pwm_value int changerange = 3; //the amount the pwm_value must change before moving onto parse and data send

int pwm_max = 910; //max of pwm range int pwm_min = 3; //min of pwm range int PWM_PIN = 3; //pwm input pin int midimax = 127; //max of MIDI range

int ccval; //value for MIDI control change const int MIDI_CHAN = 1; //set MIDI channel byte MIDI_CTRL = 9; //MIDI control number (decimal converted from hex), in this case 9 = 0x09

void setup() {  pinMode(PWM_PIN, INPUT);  Serial.begin(9600); }

void loop(){  pwmread();

 if(pwm_value >= ((pwm_prev - changerange)) && (pwm_value <= (pwm_prev + changerange))){    //filter: checks pwm_value is within the changerange of the previous measurement    //doesn't work when crossing 0 (min-max or vice versa) - but still stable enough  } //if so, do nothing  else{ //if outside the range, send data    pwmparse();    datasend();    pwm_prev = pwm_value; //save pwm_value for comparison on the next loop    } }

void pwmread() { //read pwm value from PWM_PIN  pwm_value = pulseIn(PWM_PIN, HIGH); }

void pwmparse() { //convert the pwm_value to a range that fits with MIDI  ccval = map(pwm_value, pwm_min, pwm_max, 0, midimax); //map(value, fromLow, fromHigh, toLow, toHigh) }

The AS5048A works brilliantly as a jogwheel! At the moment it needs some tweaking though: it jumps around the max/min, which I think due to the pwm_max being too high. I need to scour the datasheet for how high it actually goes, or just do it by trial and error. I’ve never seen it go below 4, or above 910 - at the moment it’s set at 0 - 1000.

Here’s the controller Definition file:

<device name="Teensy MIDI" author="TS" description="Teensy MIDI JogWhlPWM01" version="800" type="MIDI" singledeck="yes" padColumns="1" padRows="1" padSides="1" motor="no" decks="1" drivername="Teensy MIDI" vid="0x16C0 " pid="0x0485"> <fulljog cc="0x09" full="128" name="JOG" deck="1" channel="0" /> </device>

And here is the Mapper file: