// https://forum.arduino.cc/t/uno-nano-r3-servo-7seg-digit/1441460

// Mechanical, single-digit, seven-segment display.
// Each segment is attached to a servo by an arm

// See bottom of code for MUXED servos

#include <FastLED.h>   // https://github.com/FastLED/FastLED
#define NUMPIX 21      // 3pix x 7seg
#define DATAPIN 10     //
#define MAXBRIGHT 255  // adjust
CRGB led[NUMPIX];      // create WS2812B object

#include <Servo.h>      // https://github.com/arduino-libraries/Servo
#define SEGMENTS 7      // one servo per segment
Servo servo[SEGMENTS];  // seven servos

int armup = 0, armdown = 90;  // servo horn positions
byte count;                   // case counter
unsigned long timer;          // time digit change

enum segs { sega, segb, segc, segd, sege, segf, segg
          }; // enumerated segments for calling their servo-pin number

byte srvpin[] = { 2, 8, 6, 5, 4, 3, 7 };  // pins for seg a, b, c, d, e, f, g

/*
  SEGMENTS attached to SERVOS by non-interfering ARMS.
  - START SEGMENTS (segments in current digit)
  - KEEP SEGMENTS (will be used in next digit)
  - REMOVE SEGMENTS (will not be used in next digit)
  - ADD SEGMENTS (will be added to next digit)
  .         _____
  +--------/--a  \
  |      /\\_____//\
  |     |  |     |  |
  | +---|-f|     |b-|-----+
  | |   |  |_____|  |     |
  | |    \//  g--\\/----+ |
  | |    /\\_____//\    | |
  | |   |  |     |  |   | |
  | | +-|-e|     |c-|-+ | |
  | | | |  |_____|  | | | |
  | | |  \//  d  \\/  | | |
  | | |    \__ __/    | | |
  | | |       |       | | |
  + + +       +       + + +
  a f e       d       c g b <- SEGMENT SERVOS

  WS2812B GRN - Kept segment (armup)
  WS2812B RED - Removed segment (armdown)
  WS2812B BLU - Added segment (armup)
  .   _____
     /  a  \    leda  0,  1,  2
   /\\_____//\
  |  |     |  | ledb  3,  4,  5
  | f|     |b | ledf  6,  7,  8
  |  |_____|  |
   \//  g  \\/  ledg  9, 10, 11
   /\\_____//\
  |  |     |  | ledc 12, 13, 14
  | e|     |c | lede 15, 16, 17
  |  |_____|  |
   \//  d  \\/  ledd 18, 19, 20
     \_____/
*/

void setup() {
  Serial.begin(115200);

  FastLED.addLeds<WS2812B, DATAPIN, GRB>(led, NUMPIX);
  FastLED.setBrightness(MAXBRIGHT);
  FastLED.clear();
  FastLED.show();

  for (byte i = 0; i < SEGMENTS; i++) {
    servo[i].write(armdown);     // configure arms "down"
    servo[i].attach(srvpin[i]);  // servos 0 - 6 attached to servo pins
  }

  delay(1000); // settle servos
  // test(); // cycle through segment servos and WS2812B
  zero();  // starting number
  delay(820); // 180ms to move servos 90 degrees
}

void loop() {
  unsigned long servotimeout = 820;  // 1000ms/second - 180ms/servomove = 820ms
  if (millis() - timer > servotimeout) {
    timer = millis();  // set new timer

    FastLED.clear();
    FastLED.show();

    if (count > 9)  // upper bounds reached...
      count = 0;    // reset value

    switch (count) {  // transition digits
      case 0: zro_one(); break;
      case 1: one_two(); break;
      case 2: two_tre(); break;
      case 3: tre_for(); break;
      case 4: for_fiv(); break;
      case 5: fiv_six(); break;
      case 6: six_svn(); break;
      case 7: svn_eit(); break;
      case 8: eit_nin(); break;
      case 9: nin_zro(); break;
      default: break;
    }
    count++;  // increase digit count
  }
}

void keepseg(byte seg) {
  // servo[seg.write();  // No servo in keepseg();
  for (int j = 0; j < 3; j++) {              // only show in WS2812B
    led[seg * 3 + j] = CRGB(128, 255, 255);  // blu segment of three WS2812B
  }
  FastLED.show();  // show buffer
}

void addseg(byte seg) {
  servo[seg].write(armup);
  for (int j = 0; j < 3; j++) {
    led[seg * 3 + j] = CRGB(128, 255, 128);  // grn
  }
  FastLED.show();
}

void remseg(byte seg) {
  servo[seg].write(armdown);
  for (int j = 0; j < 3; j++) {
    led[seg * 3 + j] = CRGB(191, 64, 64);  // red
  }
  FastLED.show();
}

void zero() {
  for (byte i = 0; i < 6; i++) {  // SEGMENTS minus SEG G
    addseg(i);                    // call "add segment"
  }
}

void zro_one() {  // changing from ZERO to ONE...
  keepseg(segb); keepseg(segc);  // keep SEG B and C
  remseg(sega); remseg(segd); remseg(sege); remseg(segf);   // remove SEG A, D, E, and F
  // addseg(); // no addseg()
}

void one_two() {  // change from ONE to TWO
  keepseg(segb);
  remseg(segc);
  addseg(sega); addseg(segd); addseg(sege); addseg(segg);  // add SEG A, D, E, and G
}

void two_tre() {
  keepseg(sega); keepseg(segb); keepseg(segd); keepseg(segg);
  remseg(sege);
  addseg(segc);
}

void tre_for() {
  keepseg(segb); keepseg(segc); keepseg(segg);
  remseg(sega); remseg(segd);
  addseg(segf);
}

void for_fiv() {
  keepseg(segf); keepseg(segc); keepseg(segg);
  remseg(segb);
  addseg(sega); addseg(segd);
}

void fiv_six() {
  keepseg(segc); keepseg(segd); keepseg(segf); keepseg(segg);
  remseg(sega);
  addseg(sege);
}

void six_svn() {
  keepseg(segc);
  remseg(segd); remseg(sege); remseg(segf); remseg(segg);
  addseg(sega); addseg(segb);
}

void svn_eit() {
  keepseg(sega); keepseg(segb); keepseg(segc);
  // remseg(); // none
  addseg(segd); addseg(sege); addseg(segf); addseg(segg);
}

void eit_nin() {
  keepseg(sega); keepseg(segb); keepseg(segc); keepseg(segf); keepseg(segg);
  remseg(segd); remseg(sege);
  // addseg(); // none
}

void nin_zro() {
  keepseg(sega); keepseg(segb); keepseg(segc); keepseg(segf);
  remseg(segg);
  addseg(segd); addseg(sege);
}

void test() {                            // cycle through servo/WS2812 segments
  int servo90degrees = 180;              // milliseconds for 90 degree servo move
  for (int i = 0; i < SEGMENTS; i++) {   // number of segments
    for (int j = 0; j < 3; j++) {        // three WS2812 per segment
      led[i * 3 + j] = CRGB(0, 0, 255);  // blu loaded to buffer
    }
    FastLED.show();           // display buffer
    FastLED.clear();          // clear buffer
    servo[i].write(armup);    // move servo UP
    delay(servo90degrees);    // servo takes 2ms per degree to move. 90deg * 2ms/deg = 180ms
    servo[i].write(armdown);  // move servo DOWN
    delay(servo90degrees);
  }
  FastLED.show();
}

/*
  - NEXT to do:
  - Four digits
  - RTC (clock with "blinking" colon)
  - two PCAS9685 (16 channel PWM mux, daisy-chained, two "digits" per mux)
  - https://github.com/NachtRaveVL/PCA9685-Arduino
  - keep track of which of ten digit (0..9) is in each of four positions (HH:MM)
  - 12vdc power supply for Arduino VIN
  - 5V/5A BEC/buck converter for SERVOES and first PCA9685A
  - Not as genius as this cam-driven model: https://hackaday.io/project/187684-eptaora
*/