Published November 29, 2022 © GPL3+

The Circle of Life (a digitless, pixeldust clock)

Measuring time using rhythms, pulses and gravity with an animated 32x32 RGB LED matrix. A clock as object of contemplation.

AdvancedFull instructions provided312

Things used in this project

Hardware components

Adafruit Matrix Portal for RGB Matrices

Adafruit 32x32 RGB LED Matrix Panel - 4mm Pitch

Software apps and online services

Arduino IDE 2.0

Story

The Circle of Life

Entropy dictates that all ordered structures will eventually collapse. This includes the collapse of life. Hope, then, hangs on the cycles of creation and destruction, allowing for the resiliency of life.

Water, earth, light and heat, the pillars on which life rests, pulse with specific rhythms, creating cycles that begin and end. These cycles and rhythms are what we use to measure the passage of time.

The Object of Design

Water, or rather ice water, pulses every second, depositing a water particle on top with every pulse. Every ten seconds, a new layer is started, causing all the previous layers to warm up, darkening as a result. Every 60 seconds, the whole ice water structure collapses under its own weight, creating a new cycle.

SECONDS

Earth, or rather lava, as the source of primal earth, pulses every second when the water pulse hits the ground. Every minute, a lava particle is deposited on top. Every 10 minutes, a new layer of lava is started, causing all the previous layers to cool down, darkening in the process. Every 60 minutes, the whole cooled lava structure collapses under its own weight, starting again.

MINUTES

Life, in the form of green structures, pulses every second when the pulses of water and earth hit the ground. Every hour, a new life unit is deposited on top. Every 3 hours, a new layer of life units begins, causing all previous layers to grow older, darkening as a result. Every 12 hours, all layers of life collapse, allowing for a new cycle to begin.

HOURS

Finally, the sun (light & heat) completes a full cycle every 24 hours, starting at the top as a bright (orange) AM period and crawling to the bottom as a dim (purple) PM period.

AM PM

The images of these cycles provide the detailed time of day

8:36:45 PM

Hardware

I’m using the Adafruit MatrixPortal M4 which has a Cortex M4 processor, with an ESP32 co-processor, a LIS3DH accelerometer and several pins and connectors for expansions. For a LED Matrix, I chose the 32x32 RGB LED Matrix Panel with 4mm Pitch. Out of Adafruit’s comprehensive learning guide for their MatrixPortal, the three key steps are on preparing the MatrixPortal,using it with the Arduino IDE and installing the required libraries. More details on how the LED matrix works.

Other pieces of hardware will be added for more services (see “Coming Episodes”, below)

Prose in C++

I used to edit using Visual Studio Code (free, open source and full of features) and compile, upload & serial monitor using (the now legacy) Arduino IDE 1.8 (by selecting an external editor under preferences, which keeps the files in sync). But, with the release of Arduino IDE 2.0, this changed. Now I have better autocompletion, pop-up help on functions & variables, simultaneous use of serial monitor and plotter, and many others. Plus, it looks awesome in dark mode.

When starting a new project, I find it a good practice to keep all the code in a single file: this makes it easier for the IDE to find variable & function definitions (and this helps me). As I reach the first functioning draft (because writing code as a hobby is an iterative process I enjoy), I then move certain groups to specific files to keep it all nice & tidy. Plus, this also allows me to access different points in the project with a single click (by selecting the relevant tab) instead of scrolling up & down incessantly.

I don’t have to follow an orthodox C++ file naming scheme because the Arduino IDE performs a few transformations during the sketch build process that allow for greater flexibility. Just know that all.ino files in the sketch folder are concatenated together starting with the matching folder name and then in alphabetical order. To avoid using names in alphabetical order, I use.h extensions and #include them in the main (and only).ino file.

You’ll notice also that I use comments liberally. When I revisit a project, days or weeks later, this lets me recall, understand, and follow who does what and why.

The full code, as it stands today, is contained in five files:

1. declarations.h – libraries, object instantiation, global variables, and global constants. I also add the links to relevant tutorials and/or github repositories associated with these declarations.

2. clockDisplay.h – routines to update the LED matrix display with the Pixeldust simulations and with the current time

3. inputSerial.h – input data from Serial Monitor to update time (hour, minute, second) and other parameters. These routines I reuse in almost every project to avoid recompiling and reloading with every parameter test, not only saving me time, but also saving Flash cycles out of its lifetime (10k cycles for PROGMEM i.e. Flash, 100k for EEPROM) Managing Arduino Memory: Flash, SRAM, EEPROM

4. setup.h – the standard setup() and its associated routines to start resources and initiate the LED Matrix display.

5. designTwo_v3.ino – the main program loop, calling display updates as time elapses

Coming Episodes (Maybe)

UsingOther Data Input Methods

Buttons & Taps. First draft uses any button pressed to go into Config Mode. A Single Tap (i.e., from the accelerometer library) to move to next Config Item. Up/Down Buttons to scroll thru values/options for selected Config Item. Double Tap to exit Config Mode and return to Clock Mode. Still working out best way to display Config Items and their values and maintain Design Principle: no digits nor letters.
Blynk & Wi-Fi.Blynk provides a simple, but powerful graphical user interface, for both Web & Mobile. I'll reuse routines from my Smart Night Light & Alarm Clock. Once Wi-Fi is enabled, we can get the Time of Day either from Blynk or from an NPT server.
BLE & MIT App Inventor. Technically a possibility, but I've yet to find out if and how Adafruit exposes BLE from the ESP32 to the M4.

UsingAdditional Hardware (in no particular order)

Light sensor, to dim the LED Matrix according to ambient light.
Audio, for simple sound effects, using the JST connector (port A0) to a Class D audio amplifier w/8ohm speaker. Or maybe just a Piezo Buzzer using Robson Couto's Arduino Songs.
GPS, to acquire local time of day and to dim/brighten the LED matrix based on sunset/sunrise time of location.
Thermal Camera, only when detecting a living (warm) creature, the LED matrix is turned on.
EEPROM, to save current time and operational parameters after power is restored. Constant saves on existing Flash memory are a bad practice considering its write life cycle. See Adafruit Forum entry on Flash memory usage or Crisitan Maglie's FlashStorage that includes the disclaimer: IMPROPER USE OF THIS LIBRARY CAN QUICKLY AND PERMANENTLY DESTROY THE FLASH MEMORY OF YOUR MICRO.
Battery. The challenge will be battery duration (consider a 5V LED matrix always on). May have to experiment with some solar panel setup to assess (aesthetical) feasibility.
3D print case & LEDdiffuser. As last add-on to design a holder for the additional hardware.

#include "declarations.h"
#include "setup.h"
#include "clockDisplay.h"
#include "inputSerial.h"

void loop() {
  receiveData();  //READ Serial Input to set clock
  if (newData == true) parseData();
  while (((t = micros()) - prevTime) < (1000000L / maxFPS))
    ;  //Ensures FPS. Results in FPS evaluations (program loops) per second
  prevTime = t;
  if (millis() - prevSecond > 1000) {  //Update clock display once per second, else run pixelDust simulation
    prevSecond = millis();
    miniPulseDone = false;
    TOD[S]++;
    if (TOD[S] > 59) {  //60 seconds (0..59) have elapsed therefore New MIN
      TOD[M]++;
      clearSMH(S, 0, grains[S]);
      if (TOD[M] > 59) {  //60 minutes (00..59) have elapsed therefore New HR
        TOD[H]++;
        clearSMH(M, grains[S], grains[S] + grains[M]);
        if (TOD[H] > 11) {  //12 hours (00.11) have elapsed
          if (AMPM == 'P')  //changed from 11PM to 0 hours (AM) or from 12PM (noon) to 1PM
            clearSMH(H, grains[S] + grains[M], grains[S] + grains[M] + grains[H]);
          else {  //changed from 11AM to noon (M) so no clearing/incr currRow necessary: Because it won't go into addSMH, must draw topGrain for HOUR=12 here
            updateAMPM('P');
            drawHOUR();
          }
        } else
          addSMH(H, grains[S] + grains[M], grains[S] + grains[M] + grains[H]);
      } else
        addSMH(M, grains[S], grains[S] + grains[M]);
    } else
      addSMH(S, 0, grains[S]);
  } else {  //still within the same second, therefore run PixelDust simulation
    if (millis() - prevSecond > 250 && !miniPulseDone)
      miniPulse();  //mini pulse after Seconds pulse has "hit the ground"
    accel.getEvent(&event);
    xx = event.acceleration.x * 1000;
    yy = event.acceleration.y * 1000;
    zz = event.acceleration.z * 1000;
    pulse.iterate(xx, yy, zz);  //relocate grains based on accel & gravity = xx,yy,zz that is, run pixeldust simulation w/o drawing the pixels yet
  }
  drawSimulation();
}

#include <stdint.h>
//#include <Wire.h>
#include <Adafruit_LIS3DH.h>
#include <Adafruit_PixelDust.h>
#include <Adafruit_Protomatter.h>
uint8_t addrPins[] = { 17, 18, 19, 20 };
uint8_t rgbPins[] = { 7, 8, 9, 10, 11, 12 };
uint8_t clockPin = 14;
uint8_t latchPin = 15;
uint8_t oePin = 16;
// https://learn.adafruit.com/adafruit-matrixportal-m4/arduino-libraries
// https://learn.adafruit.com/adafruit-protomatter-rgb-matrix-library/arduino-library
Adafruit_Protomatter matrix(32, 6, 1, rgbPins, sizeof(addrPins), addrPins, clockPin, latchPin, oePin, true);
Adafruit_LIS3DH accel = Adafruit_LIS3DH();

const uint8_t rowHeight[3] = { 1, 3, 4 };  //options min=2,3 hr=3,4
const uint8_t smhSize[3] = { 1, 2, 3 };    //options min=1,2 hr=2,3
const uint8_t grains[3] = { 60, 40, 30 };  //pixel count (grains) for s.m.h., 0 indexed when counted, min=20, max=60
                                           //so grains[0..59] are for S, grains[60..99] are for M, grains [100..129] for H
const uint8_t S = 0;
const uint8_t M = 1;
const uint8_t H = 2;
const uint8_t clkWidth[3] = { 10, 10, 11 };  //total width in pixels for s.m.h
const uint8_t startCol[3] = { 22, 12, 1 };   //starting X position for seconds, minutes, hours
uint8_t currRow[3] = { 0, 0, 0 };            //current row receivng new grains for s.m.h,  0 indexed when counted
uint16_t clkColor[3][6];                     //six color intensitites for s.m.h.
uint16_t basePM, baseAM, crawlPM, crawlAM;   //colors for AMPM
uint8_t TOD[3] = { 0, 0, 0 };                //time of day in s.m.h: Holds currently running s.m.h vs Display matrix shows the elapsed s.m.h
                                             //so displayed[s.m.h] = TOD[s.m.h] + 1, meaning s.m=60 is never displayed
char AMPM = 'P';                             // midnight is 0 hours

// https://learn.adafruit.com/adafruit-matrixportal-m4/arduino-pixel-dust-demo
// https://github.com/adafruit/Adafruit_PixelDust
Adafruit_PixelDust pulse(32, 32, grains[S] + grains[M] + grains[H], 1, 128, false);  //100 = jumpiness, false = less computation & more loony
const uint8_t maxFPS = 60;

double xx, yy, zz;
sensors_event_t event;

dimension_t x, y;
uint32_t prevTime = 0;
uint32_t prevSecond, t;
int i, j, k, c, r;  // for-loop counters

const byte inputChars = 32;
char receivedChars[inputChars];
boolean newData = false;
boolean miniPulseDone = false;

void receiveData() {
  static boolean recvInProgress = false;
  static byte ndx = 0;
  char startMarker = '<';
  char endMarker = '>';
  char rc;
  while (Serial.available() > 0 && newData == false) {
    rc = Serial.read();
    if (recvInProgress == true) 
      if (rc != endMarker) {
        receivedChars[ndx] = rc;
        ndx++;
        if (ndx >= inputChars) ndx = inputChars - 1;
      } else {
        receivedChars[ndx] = '\0';  // terminate the string
        recvInProgress = false;
        ndx = 0;
        newData = true;
      }
    else 
      if (rc == startMarker) recvInProgress = true;
  }
}

void parseData() {
  char tempChars[inputChars];
  int v1, v2, v3;
  newData = false;
  strcpy(tempChars, receivedChars);
  char* strtokIndx;
  strtokIndx = strtok(tempChars, ",");
  v1 = atoi(strtokIndx);  //input how many hours
  strtokIndx = strtok(NULL, ",");
  v2 = atoi(strtokIndx);  //input how many minutes
  strtokIndx = strtok(NULL, ",");
  v3 = atoi(strtokIndx);  //input how many seconds
  if (v1 > 11) AMPM = 'P';
  else AMPM = 'A';
  if (v1 > 12) v1 -= 12;
  TOD[H] = v1;
  TOD[M] = v2;
  TOD[S] = v3;
  updateAMPM('N');
  for (k = S; k <= M; k++) currRow[k] = int((TOD[k] - 1) / clkWidth[k]);
  currRow[H] = int((TOD[H] - 1) / 3);
  Serial.printf("hrs:%d mins:%d secs:%d", TOD[H], TOD[M], TOD[S]);
  Serial.println();
  for (k = S; k <= H; k++) 
    for (int i = 0; i < TOD[k]; i++) 
      if (k == M) 
        for (j = 0; j < smhSize[M]; j++)
          matrix.drawPixel(startCol[k] + (i % clkWidth[k]), (i / clkWidth[k]) * rowHeight[M] + j, clkColor[k][currRow[k] - i / clkWidth[k]]);
        else 
          if (k == S)
            matrix.drawPixel(startCol[k] + (i % clkWidth[k]), i / clkWidth[k], clkColor[k][currRow[k] - i / clkWidth[k]]);
          else 
            for (c = 0; c < smhSize[H]; c++)
              for (r = 0; r < smhSize[H]; r++)
                matrix.drawPixel(4 * (i + 1) - int(i / 3) * 12 - 3 + c, int(i / 3) * rowHeight[H] + r, clkColor[k][currRow[k] - int(i / 3)]);
  matrix.show();
  delay(1000);
}

void drawHOUR() {
  for (c=0;c<smhSize[H];c++)
    for (r=0;r<smhSize[H];r++)          
      matrix.drawPixel(4*TOD[H]-int((TOD[H]-1)/3)*12-3+c, int((TOD[H]-1)/3)*rowHeight[H]+r, clkColor[H][currRow[H]-int((TOD[H]-1)/3)]);
      // to understand these parameters, see excel docs
}

void updateAMPM(char newVal) {
  if (newVal != 'N') 
    AMPM = newVal;
  byte hour24 = (AMPM=='A')*TOD[H] + (AMPM=='P')*(TOD[H]+12) -12*(TOD[H]==12);
  for (i=0; i<32; i++)
    matrix.drawPixel(0,i,basePM*(AMPM=='P') + baseAM*(AMPM=='A'));
  for (i=0; i<8; i++)
    matrix.drawPixel(0,hour24 + i,crawlPM*(AMPM=='P') + crawlAM*(AMPM=='A')); 
}

void clearSMH(uint8_t smh, int firstPixel, int lastPixel) { 
  for (i=firstPixel; i<lastPixel; i++) { // Clear pixelDust & place grains[smh] on top grains/clkWidth rows (+4 if hour=13) as pixelDust for drop sim
    pulse.getPosition(i, &x, &y); 
    pulse.clearPixel(x, y); 
    pulse.setPosition(i, startCol[smh] + ((i - firstPixel) % clkWidth[smh]), (TOD[H]==13)*rowHeight[H] + ((i - firstPixel) / clkWidth[smh]));
  }   
  currRow[smh] = 0; // restart currRow
  if (smh != H) {
    TOD[smh] = 0; // restart s.m at 0
  }else { // for H, clearSMH is called only if TOD[H]>11
    if (TOD[smh] == 12) { //time changed from 23:59:59 (11PM) to 0 hours (12AM)
      updateAMPM('A');
      TOD[smh] = 0;
    }else { //time changed from 12:59:59 (PM) to 1PM so must draw HOUR=1 topGrain here because it didn't go thru addSMH
      TOD[smh] = 1;
      matrix.fillRect(startCol[H], 0, clkWidth[H], 3, 0x0); //erase hours 2 & 3 from currRow = 0 
      drawHOUR();
    }
  }
}

void addSMH(uint8_t smh, int firstPixel, int lastPixel) {
  bool newRow = false; //drop to the next row
  if (TOD[smh] != 1) //to filter out MODULUS=1 when TOD[]=1: drop new row only if not 1st s.m.h
    if ((smh == H && TOD[smh] % 3 == 1) || (smh != H && TOD[smh] % clkWidth[smh] == 1)) { //if MOD=1, TOD[smh] is first pixel on new row
      currRow[smh]++;
      newRow = true;
    }
  switch (smh) {   // add a Top Grain and recolor previous (existing) rows if newRow
    case S: matrix.drawPixel(startCol[smh] + ((TOD[smh] - 1) % clkWidth[smh]), currRow[smh], clkColor[smh][0]);
            if (newRow)
              for (i=currRow[smh]-1; i>=0; i--) 
                for (j=startCol[smh]; j<startCol[smh] + clkWidth[smh] + 1; j++) 
                  matrix.drawPixel(j, i, clkColor[smh][currRow[smh] - i]); 
            break;
    case M: for (k=0; k<smhSize[M]; k++)
              matrix.drawPixel(startCol[smh] + ((TOD[smh] - 1) % clkWidth[smh]), currRow[smh] * rowHeight[M] + k, clkColor[smh][0]);
            if (newRow)
              for (k=0; k<smhSize[M]; k++)
                for (i=currRow[smh]-1; i>=0; i--) 
                  for (j=startCol[smh]; j<startCol[smh] + clkWidth[smh] + 1; j++) 
                    matrix.drawPixel(j, i * rowHeight[M] + k, clkColor[smh][currRow[smh] - i]);
            break;
    case H: drawHOUR();
            if (newRow)
              for (i=currRow[smh]-1; i>=0; i--) 
                for (j=1;j<=9;j+=4)
                  for (c=0;c<smhSize[H];c++)
                    for (r=0;r<smhSize[H];r++)         
                      matrix.drawPixel(j+c, rowHeight[H]*i+r, clkColor[H][currRow[H]-i]);  
            updateAMPM('N'); //update AMPM crawler
            break;
  }
  for (i = firstPixel;  i < lastPixel; i++)  { //clear sim pixels & place new explosion below currRow
    pulse.getPosition(i, &x, &y); 
    pulse.clearPixel(x,y); 
    while (!pulse.setPosition(i, random(startCol[smh],startCol[smh]+clkWidth[smh]), random((currRow[smh]+1)*rowHeight[smh],32))); }
}

void miniPulse() {
  miniPulseDone = true;
  for (i=(grains[S] + grains[M]) * 0.85; i<grains[S] + grains[M]; i++)  {  //animate the last 15% the mins grains
    pulse.getPosition(i, &x, &y); 
    pulse.clearPixel(x, y);  
    while (!pulse.setPosition(i, random(startCol[M], startCol[M] + clkWidth[M]), random(20, 32)));    
  }
  for (i=(grains[S] + grains[M] + grains[H]) * 0.85; i<grains[S] + grains[M] + grains[H]; i++)  {  //animate the last 15% of the hrs grains
    pulse.getPosition(i, &x, &y); 
    pulse.clearPixel(x, y);  
    while (!pulse.setPosition(i, random(startCol[H], startCol[H] + clkWidth[H]), random(20, 32)));  
  }
}

void drawSimulation() {
  for (k=S; k<=H; k++)  //clear area of all s.m.h below currRow or from 0 when new s.m.h starts
    matrix.fillRect(startCol[k], currRow[k]*rowHeight[k] + (TOD[k]>0)*(k + 1), clkWidth[k], 32-(currRow[k]*rowHeight[k] + (TOD[k]>0)*(k + 1)),0x0);
  for (k=S; k<=M; k++)  //redraw border pixels
    for (i=33-(grains[k+1]/10); i<32; i++) 
      matrix.drawPixel(startCol[k] - 1, i, clkColor[k+1][0x0]);  
  for (i=0; i<grains[S] + grains[M] + grains[H]; i++) {  //draw simulation s.m.h grains in their (latest) position
    pulse.getPosition(i, &x, &y);
    matrix.drawPixel(x, y, clkColor[(i>=grains[S]) + (i>=grains[S]+grains[M])][0x0]);
  }
  matrix.show(); 
}

void setColors() {
  for (i = 5; i >= 0; i--) {
    clkColor[S][i] = matrix.color565(0, 5 + 10 * (5 - i), 50 + 40 * (5 - i));
    clkColor[M][i] = matrix.color565(20 + 40 * (5 - i), 0, 0);
  }
  clkColor[H][5] = matrix.color565(100, 0, 100);
  clkColor[H][4] = matrix.color565(0, 100, 0);

  clkColor[H][0] = matrix.color565(20, 180, 20);
  clkColor[H][1] = matrix.color565(10, 100, 10);
  clkColor[H][2] = matrix.color565(5, 60, 5);
  clkColor[H][3] = matrix.color565(0, 20, 0);
  basePM = matrix.color565(20, 0, 20);
  crawlPM = matrix.color565(110, 0, 100);
  baseAM = matrix.color565(90, 20, 0);
  crawlAM = matrix.color565(150, 80, 0);
}

void err(int x) {
  pinMode(LED_BUILTIN, OUTPUT);
  switch (x) {
    case 100: Serial.println("Error in matrix:"); // Very Fast blink = Matrix error
      break;
    case 1000: Serial.println("Error in pixelDust"); // Slow blink = malloc error
      break;
    case 400: Serial.println("Error in accelerometer"); // Fast blink = I2C error
      break;
  }
  for (i = 1;; i++) {
    digitalWrite(LED_BUILTIN, i & 1);
    delay(x);
  }
}

void setup() {
  Serial.begin(115200);
  //while (!Serial) delay(10);
  //ProtomatterStatus status = matrix.begin();
  //if (status != 0) err(100);
  if (!matrix.begin()) err(100);
  if (!pulse.begin()) err(1000); 
  if (!accel.begin(0x19)) err(400);                              
  accel.setRange(LIS3DH_RANGE_4_G);  // 2, 4, 8 or 16 G
  setColors();
  int l = 0;
  for (k = S; k <= H; k++) { //iterate s.m.h
    for (j = 0; j < 32; j++) 
      pulse.setPixel(startCol[k] - 1, j);  //boundaries
    for (i = grains[S] * (k > S) + grains[M] * (k > M); i < grains[k] + grains[S] * (k > S) + grains[M] * (k > M); i++) {  //create & draw first s.m.h explosions
      while (!pulse.setPosition(i, random(startCol[k], startCol[k] + clkWidth[k]), random(1, 32)))
        ;  //(from row 1, not row 0, to row 31)
      pulse.getPosition(i, &x, &y);
      matrix.drawPixel(x, y, clkColor[k][0x0]);
    }
  }
  matrix.show();
}

Credits

Pedro Martin

8 projects • 15 followers

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The Circle of Life (a digitless, pixeldust clock)

The Circle of Life (a digitless, pixeldust clock)

Things used in this project

Hardware components

Software apps and online services

Story

The Circle of Life

The Object of Design

Hardware

Prose in C++

Coming Episodes (Maybe)

Code

designTwo_v3.ino

declarations.h

inputSerial.h

clockDisplay.h

setup.h

Credits

Pedro Martin

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