M5Stack Christmas 3D POV Display

I made a mini 3D POV (Persistence of Vision) Display to enhance the Christmas spirit.

Constitution

The LEDs are arranged three-dimensionally and rotated to display an image with an afterimage. I used a compact ATOM Lite as a microcomputer.

The photo reflector sensor QTR-1A detects rotation.

Power is supplied to the rotating part by the wireless charge module.

Housing

The housing was made with a 3D printer.

LED 5 cells are arranged in a 10-stage spiral.

Operation

Arduino Code

I used the following SPI input LED Dotstar library.https://github.com/adafruit/Adafruit_DotStar

One lap is displayed in 20 divisions.

#include <Adafruit_DotStar.h>
#include <SPI.h> 

#define NUMPIXELS 50

#define Div 20
#define Bright 20

#define itrPin 22

int num = 0;
int num2 = 0;

int numRot = 0;
int numDiv = 0; 
int stateRot = 0;

int stateDiv = 0;
int UpDown = 0;

unsigned long rotTime, timeOld, timeNow;

uint32_t colorNum[] = {
  0xFF0000,
  0xFFFF00,
  0x00FF00,
  0x00FFFF,
  0x0000FF
};

#define DATAPIN    25
#define CLOCKPIN   21
Adafruit_DotStar strip(NUMPIXELS, DATAPIN, CLOCKPIN, DOTSTAR_BGR);

void setup() {
  Serial.begin(115200);
  
  strip.begin(); 
  strip.setBrightness(Bright);
  strip.show(); 
  
  pinMode(itrPin, INPUT);
  delay(500);

  attachInterrupt(digitalPinToInterrupt(itrPin), RotCount, RISING );
}

void loop() {
  if(stateDiv == 1 &&micros() - timeOld > rotTime / Div * (numDiv)){
    stateDiv = 0;
  }
  
  if(stateDiv == 0 && micros() - timeOld < rotTime / Div * (numDiv + 1)){
    stateDiv = 1;
    
    strip.clear();

    for(int i=0;i<5; i++){
      strip.setPixelColor(i + (numRot/2) * 5, 0xFF0000);
    }

    strip.show();

    numDiv++;
    if(numDiv >= Div ) numDiv = 0;

    num++;
    if(num >= 5 ) num = 0;
  }
}

void RotCount() {
  timeNow = micros();
  rotTime = timeNow - timeOld;
  timeOld = timeNow;

  if(UpDown == 0){
    numRot++;
    if(numRot == 19 ) {
      UpDown = 1;
    }
  }else{
    numRot--;
    if(numRot <= 0 ) {
      UpDown = 0;
    }
  }
  
  Serial.println("int");
}

Christmas Tree

Star

Cube

Clock