Crypto Currency Ticker Using Esp8266 and OLED display

psadminetechpath January 13, 2022

Introduction:

Ticker is basically a display which connects with your local WiFi router or access-point and fetch online crypto currency data from api and displays on its screen. In this ticker we are going to use esp8266 nodeMCU and 0.98” OLED display for demonstration.

Things you will need:

  • Node MCU or any ESP8266
  • 0.98 inch OLED display
  • Lipo battery
  • 100k resistors
  • TP4056 module
  • USB to serial programmer in case of standalone Esp8266
  • Arduino IDE – Software
  • Breadboard and connection cables

Circuit Diagram:

Crypto-Ticker-Circuit-Diagram

Code: 

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <ArduinoJson.h>
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <Wire.h>
#include <U8g2lib.h>

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);

const char* ssid     = "username";
const char* password = "password";

int analogInPin  = A0;    
int sensorValue;   
float calibration = 0.36; 
int bat_percentage;

WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "0.in.pool.ntp.org", 5.5*3600, 60000);

#define CG_URL "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin%2Cethereum%2Cdogecoin%2Cshiba-inu%2Cpolkadot&vs_currencies=inr%2Cusd&include_last_updated_at=true&include_24hr_change=true"
const char *fingerprint  = "33 C5 7B 69 E6 3B 76 5C 39 3D F1 19 3B 17 68 B8 1B 0A 1F D9";

String payload = "{}";

void setup()
{
  Serial.begin(115200);
  Serial.setDebugOutput(false);
  delay(10);

  u8g2.begin();
  u8g2.enableUTF8Print();

  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);
  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_helvB08_tf);

  u8g2.setCursor(1, 15);
  u8g2.print("Connecting to WiFi ");
  u8g2.setCursor(1, 25);
  u8g2.sendBuffer();

  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
    u8g2.print(".");
    u8g2.sendBuffer();
  }
  timeClient.begin();

 Serial.println("");
 Serial.println("WiFi connected");
 Serial.print("IP address: ");
 Serial.println(WiFi.localIP());
 u8g2.setCursor(1, 45);
    u8g2.print("Connected to ");
    u8g2.print(ssid);
    u8g2.setCursor(1, 55);
    u8g2.print("IP Address ");
    u8g2.print(WiFi.localIP());
    u8g2.sendBuffer();
    delay(5000);
}

void loop()
{ 
  if (WiFi.status() == WL_CONNECTED)
  {  
    WiFiClientSecure client;
    client.setFingerprint(fingerprint);
    HTTPClient http; 
    delay(200);

    while (!timeClient.update()) {
      timeClient.forceUpdate();
    }
    Serial.println();
    Serial.print("Time     - ");
    Serial.println(timeClient.getFormattedTime());
    
    u8g2.clearBuffer();
    u8g2.setFont(u8g2_font_helvB18_tf);
    u8g2.setCursor(23, 40);
    u8g2.print(timeClient.getFormattedTime());
    u8g2.drawFrame(110,1,13,6);
    u8g2.drawFrame(123,3,1,2);
    u8g2.drawBox(111,2,bat_percentage,4);
    u8g2.sendBuffer();
    delay (1000);
    
    sensorValue = analogRead(analogInPin);
    float voltage = (((sensorValue * 3.3) / 1024) * 2 + calibration); //multiply by two as voltage divider network is 100K & 100K Resistor

    bat_percentage = mapfloat(voltage, 2.8, 4.2, 0, 11); //2.8V as Battery Cut off Voltage & 4.2V as Maximum Voltage
 
  if (bat_percentage >= 11)
  {
    bat_percentage = 11;
  }
  if (bat_percentage <= 0)
  {
    bat_percentage = 1;
  }
  Serial.print("Analog Value = ");
  Serial.print(sensorValue);
  Serial.print("\t Output Voltage = ");
  Serial.print(voltage);
  Serial.print("\t Battery Percentage = ");
  Serial.println(bat_percentage);
  delay(1000);
  delay (20);
  
    payload = "{}";

    http.begin(client, CG_URL);
    Serial.println();
    Serial.print("Coingecko URL - ");
    Serial.println(CG_URL);

    int httpCode = http.GET();
    
    if (httpCode > 0) { 
      payload = http.getString();
      DynamicJsonDocument doc(800);
      DeserializationError error = deserializeJson(doc, payload);
      if (error) 
      {
        Serial.print(F("deserializeJson() failed: "));
        Serial.println(error.f_str());
        delay(5000);
        return;
      }
     JsonObject bitcoin = doc["bitcoin"];
      double bitcoin_inr = bitcoin["inr"]; 
      double bitcoin_usd_24h_change = bitcoin["usd_24h_change"]; 
      double bitcoin_usd = bitcoin["usd"]; 
     
      JsonObject ethereum = doc["ethereum"];
      double ethereum_inr = ethereum["inr"];
      double ethereum_usd_24h_change = ethereum["usd_24h_change"]; 
      double ethereum_usd = ethereum["usd"]; 
      
      JsonObject dogecoin = doc["dogecoin"];
      double dogecoin_inr = dogecoin["inr"];
      double dogecoin_usd = dogecoin["usd"];
      double dogecoin_usd_24h_change = dogecoin["usd_24h_change"]; 
      long dogecoin_last_updated_at = dogecoin["last_updated_at"]; 

      JsonObject shibainu = doc["shiba-inu"];
      double shibainu_inr = shibainu["inr"]; 
      double shibainu_usd_24h_change = shibainu["usd_24h_change"]; 
      double shibainu_usd = shibainu["usd"]; 

      JsonObject polkadot = doc["polkadot"];
      double polkadot_inr = polkadot["inr"];
      double polkadot_usd_24h_change = polkadot["usd_24h_change"]; 
      double polkadot_usd = polkadot["usd"]; 

      // Edit below your coin holdings here
     double holdings_ethereum  =  0.555;
      double holdings_bitcoin  =  0;
      double holdings_dogecoin =  0.5443;
      double holdings_polkadot    =  0.0324;
      double holdings_shibainu   =  4800000;

      Serial.print("Bitcoin  - $");
      Serial.print("   $");
      Serial.print(bitcoin_usd);
      Serial.println();
      Serial.print("Ethereum  - $");
      Serial.print("   $");
      Serial.print(ethereum_usd);
      Serial.println();
      Serial.print("Dogecoin  - $");
      Serial.print("   $");
      Serial.print(dogecoin_usd);
      Serial.println();
      Serial.print("Polkadot  - $");
      Serial.print("   $");
      Serial.print(polkadot_usd);
      Serial.println();
      Serial.print("shibainu  - $");
      Serial.print("   $");
      Serial.print(shibainu_usd);
      Serial.println();

      double holdings =
        (ethereum_usd   * holdings_ethereum) +
        (bitcoin_usd   * holdings_bitcoin) +
        (dogecoin_usd  * holdings_dogecoin) +
        (polkadot_usd * holdings_polkadot) +
        (shibainu_usd    * holdings_shibainu);

      Serial.println(holdings);
      Serial.println();
      Serial.println();
      Serial.println();
      Serial.println();
  
      draw("BITCOIN - BTC",    bitcoin_usd,   2,  bitcoin_usd_24h_change,   "$");
      draw("ETHEREUM - ETH",   ethereum_usd,  2,  ethereum_usd_24h_change,  "$");
      draw("SHIBA-INU - SHIB", shibainu_usd, 6,  shibainu_usd_24h_change, "$");
      draw("DOGECOIN - DOGE", dogecoin_usd, 4,  dogecoin_usd_24h_change, "$");
      draw("POLKADOT - DOT",     polkadot_usd,  2,  polkadot_usd_24h_change,    "$");
      draw("HOLDINGS  ",       holdings,      0,  0,                        "$");
    }
    http.end();  
  }
}
float mapfloat(float x, float in_min, float in_max, float out_min, float out_max)
{
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}
void drawScrollString(int16_t offset, const char *s)
{
  static char buf[36];  // should for screen with up to 256 pixel width
  size_t len;
  size_t char_offset = 0;
  u8g2_uint_t dx = 0;
  size_t visible = 0;
  len = strlen(s);
  if ( offset < 0 )
  {
    char_offset = (-offset) / 8;
    dx = offset + char_offset * 8;
    if ( char_offset >= u8g2.getDisplayWidth() / 8 )
      return;
    visible = u8g2.getDisplayWidth() / 8 - char_offset + 1;
    strncpy(buf, s, visible);
    buf[visible] = '\0';
    u8g2.setFont(u8g2_font_8x13_mf);
    u8g2.drawStr(char_offset * 8 - dx, 62, buf);
  }
  else
  {
    char_offset = offset / 8;
    if ( char_offset >= len )
      return; // nothing visible
    dx = offset - char_offset * 8;
    visible = len - char_offset;
    if ( visible > u8g2.getDisplayWidth() / 8 + 1 )
      visible = u8g2.getDisplayWidth() / 8 + 1;
    strncpy(buf, s + char_offset, visible);
    buf[visible] = '\0';
    u8g2.setFont(u8g2_font_8x13_mf);
    u8g2.drawStr(-dx, 62, buf);
  }
}
void draw(char *s, double coinprice, int prec, double change, String currency)
{
  int16_t offset = -(int16_t)u8g2.getDisplayWidth();
  int16_t len = strlen(s);

  char pricelen[10];
  dtostrf(coinprice, 4, prec, pricelen);
  int xPos = 64 - (((strlen(pricelen)) * 11) / 2);

  for (;;)
  {
    u8g2.clearBuffer();
    u8g2.setFont(u8g2_font_helvB18_tf);
    u8g2.setCursor(xPos - 11, 30);
    u8g2.print(currency);
    u8g2.print(coinprice, prec);

    if (change != 0) {
      u8g2.setFont(u8g2_font_helvB10_tf);
      u8g2.setCursor(38, 47);
      if (change > 0) {
        u8g2.print("+");
      }
      u8g2.print(change, 2);
      u8g2.print("%");
    }

    drawScrollString(offset, s);
     u8g2.drawFrame(110,1,13,6);
    u8g2.drawFrame(123,3,1,2);
    u8g2.drawBox(111,2,bat_percentage,4);
    u8g2.sendBuffer();
    delay(10);
    offset += 2;
    if ( offset > len * 8 + 1 )
      break;
  }
}

Code Explanation:

Edit your router WiFi username and password here

const char* ssid     = "username";
const char* password = "password";

Replace bellow line with your OLED model from u8g2 library if needed 

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);

Calibration factor need to be adjusted as per resistors value and final output in below line 

int analogInPin  = A0;    
int sensorValue;   
float calibration = 0.36; 
int bat_percentage;

Replace multiplication factor value for ntp client as per your local time zone. (GMT+5.5 is for India time) 

NTPClient timeClient(ntpUDP, "0.in.pool.ntp.org", 5.5*3600, 60000);

You can change ticker Crypto currencies as per your choice in bellow URL link

#define CG_URL "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin%2Cethereum%2Cdogecoin%2Cshiba-inu%2Cpolkadot&vs_currencies=inr%2Cusd&include_last_updated_at=true&include_24hr_change=true"

If your ticker is not working, do check if this is updated fingerprint for coingencko.com. Or you can get updated fingerprint from GRC | SSL TLS HTTPS Web Server Certificate Fingerprints . 

const char *fingerprint  = "33 C5 7B 69 E6 3B 76 5C 39 3D F1 19 3B 17 68 B8 1B 0A 1F D9";

Edit your crypt holdings here to get total holdings on crypto-ticker screen. 

      double holdings_ethereum  =  0.555;
      double holdings_bitcoin  =  0;
      double holdings_dogecoin =  0.5443;
      double holdings_polkadot    =  0.0324;
      double holdings_shibainu   =  4800000;

Prototype :

.

Downloads:

Video:

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