Arduino code to print James' subscriber count

JamesSubsMatrix.ino

// ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

#include "secrets.h"

const char* ssid     = SECRET_SSID;      // SSID of local network
const char* password = SECRET_PASSWORD;    // Password on network

const long UPDATE_INTERVAL_MILLIS = 10L * 60L * 1000L;
//const long UPDATE_INTERVAL_MILLIS = 1L * 1000L;

const char* API_URL = "https://getyoutubesubscribercount20210328114249.azurewebsites.net/api/GetStats";

// ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

//#define DEBUG_ESP_PORT Serial

/*
  The code for this project is based on code originally written by Pawel A. Hernik
  https://youtu.be/mn9L85bhyjI

  Revised by Lewis for DIY Machines
  https://youtu.be/QWaVYCVoqbc
  
  I made an error in the video - you need to input your YouTube Channel ID above, not your User ID.

  VCC - 3.3v
  GND - G
  D8 - DataIn
  D7 - LOAD/CS
  D6 - CLK
  
  If you have difficulties try going to your Arduino IDE Board Manager and rolling back the 'ESP8266 by ESP8266 Community' to
  version 2.4.2 
*/

#include "Arduino.h"
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266HTTPClient.h>

ESP8266WiFiMulti WiFiMulti;
#include <WiFiClientSecureBearSSL.h>


#define NUM_MAX 4
#define ROTATE 90


// for NodeMCU 1.0
#define DIN_PIN 15  // D8
#define CS_PIN  13  // D7
#define CLK_PIN 12  // D6

#include "max7219.h"
#include "fonts.h"

const char HeartChar = ' ' + (sizeof(font)-1)/6 - 5;
const char SmileyChar = ' ' + (sizeof(font)-1)/6 - 8;


void setup() 
{
  Serial.begin(115200);
  initMAX7219();
  sendCmdAll(CMD_SHUTDOWN,1);
  sendCmdAll(CMD_INTENSITY,0);
  printStringWithShift((String("Load ") + String(SmileyChar)).c_str(), 0);
  Serial.print("Connecting WiFi ");
  WiFi.mode(WIFI_STA);
  WiFiMulti.addAP(SECRET_SSID, SECRET_PASSWORD);
}
// =======================================================================

void loop()
{
  if (WiFiMulti.run() == WL_CONNECTED) {
    Serial.println("Getting data ...");
    //printStringWithShift("  ... YT ...",15);
    int views, cnt = 0;
    String subs;
    String yt1;
    if(getYTSubs(subs,&views)==0) {
      Serial.println(subs);
      yt1 = subs;
    } else {
      yt1 = "   Error";
    }
    auto m = String("    ") + String(HeartChar) + String(" ") + yt1;
    printStringWithShift(m.c_str(),50);
    delay(UPDATE_INTERVAL_MILLIS);
  }
}
// =======================================================================

int showChar(char indexIntoFont, const uint8_t *font)
{
  int bytesPerFontChar = pgm_read_byte(font);
  const auto fontDataOffset = font + 1 + indexIntoFont * bytesPerFontChar;
  int numCols = pgm_read_byte(fontDataOffset);
  for (int c = 0; c < numCols; c++)
    scr[NUM_MAX*8 + c] = pgm_read_byte(fontDataOffset + 1 + c);
  scr[NUM_MAX*8 + numCols] = 0;
  return numCols;
}

// =======================================================================
int dualChar = 0;

unsigned char convertPolish(unsigned char _c)
{
  unsigned char c = _c;
  if(c==196 || c==197 || c==195) {
    dualChar = c;
    return 0;
  }
  if(dualChar) {
    switch(_c) {
      case 133: c = 1+'~'; break; // 'ą'
      case 135: c = 2+'~'; break; // 'ć'
      case 153: c = 3+'~'; break; // 'ę'
      case 130: c = 4+'~'; break; // 'ł'
      case 132: c = dualChar==197 ? 5+'~' : 10+'~'; break; // 'ń' and 'Ą'
      case 179: c = 6+'~'; break; // 'ó'
      case 155: c = 7+'~'; break; // 'ś'
      case 186: c = 8+'~'; break; // 'ź'
      case 188: c = 9+'~'; break; // 'ż'
      //case 132: c = 10+'~'; break; // 'Ą'
      case 134: c = 11+'~'; break; // 'Ć'
      case 152: c = 12+'~'; break; // 'Ę'
      case 129: c = 13+'~'; break; // 'Ł'
      case 131: c = 14+'~'; break; // 'Ń'
      case 147: c = 15+'~'; break; // 'Ó'
      case 154: c = 16+'~'; break; // 'Ś'
      case 185: c = 17+'~'; break; // 'Ź'
      case 187: c = 18+'~'; break; // 'Ż'
      default:  break;
    }
    dualChar = 0;
    return c;
  }    
  switch(_c) {
    case 185: c = 1+'~'; break;
    case 230: c = 2+'~'; break;
    case 234: c = 3+'~'; break;
    case 179: c = 4+'~'; break;
    case 241: c = 5+'~'; break;
    case 243: c = 6+'~'; break;
    case 156: c = 7+'~'; break;
    case 159: c = 8+'~'; break;
    case 191: c = 9+'~'; break;
    case 165: c = 10+'~'; break;
    case 198: c = 11+'~'; break;
    case 202: c = 12+'~'; break;
    case 163: c = 13+'~'; break;
    case 209: c = 14+'~'; break;
    case 211: c = 15+'~'; break;
    case 140: c = 16+'~'; break;
    case 143: c = 17+'~'; break;
    case 175: c = 18+'~'; break;
    default:  break;
  }
  return c;
}

// =======================================================================

void printCharWithShift(unsigned char c, int shiftDelay) {
  c = convertPolish(c);
  if (c < ' ' || c > MAX_CHAR) return;
  c -= 32;
  int w = showChar(c, font);
  for (int i=0; i<w+1; i++) {
    delay(shiftDelay);
    scrollLeft();
    refreshAll();
  }
}

// =======================================================================

void printStringWithShift(const char* s, int shiftDelay){
  while (*s) {
    printCharWithShift(*s++, shiftDelay);
  }
}

// =======================================================================
unsigned int convToInt(const char *txt)
{
  unsigned int val = 0;
  for(int i=0; i<strlen(txt); i++)
    if(isdigit(txt[i])) val=val*10+(txt[i]&0xf);
  return val;
}
// =======================================================================

int getYTSubs(String &subs, int *pViews)
{
  if(!pViews) return -2;

  *pViews = 0;
  
  std::unique_ptr<BearSSL::WiFiClientSecure> client(new BearSSL::WiFiClientSecure);

  //client->setFingerprint(fingerprint);
  client->setInsecure();

  HTTPClient https;

  String url = API_URL;
  
//  Serial.print("[HTTPS] begin...\n");
  if (!https.begin(*client, url.c_str())) {
    Serial.println("[HTTPS] Failed");
    return -3;
  }

  int httpCode = https.GET();

//  Serial.println("[HTTPS] Success");
//  Serial.println(httpCode);

  String payload = https.getString();
//  Serial.println("PAYLOAD SIZE");
//  Serial.println(payload.length());
//  Serial.println(payload.c_str());

  subs = payload;

  https.end();
  return 0;
}