HTTPS Get Request for Nano Price from Coingecko with ESP8266

Description: A Wemos Lolin D1 Mini Pro V2 connects to the internet, sends a GET Request to the Coingecko API for the Nano Price, and then updates the Nano price on an LCD display every 20 seconds.

Notes: CS (Chip-Select) is on pin 15. Make sure to set the baud rate to 115200 in the Serial Monitor.

Resources: https://arduinojson.org/v6/assistant/

Supplies:

1 – Breadboard 400 Points
1 – Wemos Lolin D1 Mini Pro V2  >> Link <<
1 – SPI Colour Square LCD 240×240 (Pimoroni)  >> Link <<

Arduino Code:

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClientSecureBearSSL.h>
#include <ArduinoJson.h>

#include "DFRobot_GDL.h"
#define TFT_DC 16
#define TFT_CS 15
#define TFT_RST 5 // BL Pin on the LCD

DFRobot_ST7789_240x240_HW_SPI screen(/*dc=*/TFT_DC,/*cs=*/TFT_CS,/*rst=*/TFT_RST);

void setup() {

  Serial.begin(115200);
  screen.begin();

  WiFi.mode(WIFI_STA);
  WiFi.begin("Network Name", "password"); // Change WiFi "Network Name" and "password" to yours
  Serial.println("");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println(F("\n\rWiFi connected!"));

}

void loop() {

  std::unique_ptr<BearSSL::WiFiClientSecure>client(new BearSSL::WiFiClientSecure);
  client->setInsecure();
  HTTPClient https;
  https.begin(*client, "https://api.coingecko.com/api/v3/simple/price?ids=nano&vs_currencies=USD");

    //get json data
    int httpCode = https.GET();

    if (httpCode > 0) {  //Check the returning code
      
      const char* json = https.getString().c_str();
      
      // Stream& input;
      StaticJsonDocument<64> doc;
      DeserializationError error = deserializeJson(doc, json);

      if (error) {
       Serial.print(F("deserializeJson() failed: "));
       Serial.println(error.f_str());
        return;
        }

       float nano_usd = doc["nano"]["usd"]; // 6.46
       Serial.println("");
       Serial.print("$");
       Serial.print(nano_usd);
       Serial.print(" USD");

  screen.setTextWrap(true); //Set to text auto-wrap mode, true=Auto-wrap, false=No auto-wrap

  screen.fillScreen(COLOR_RGB565_WHITE);
  screen.setTextColor(COLOR_RGB565_BLACK);

  screen.setTextSize(1);
  screen.setFont(&FreeMono18pt7b);
  screen.setCursor(/*x=*/80,/*y=*/55);
  screen.print("NANO");

  screen.setTextSize(1);
  screen.setFont(&FreeMono9pt7b);
  screen.setCursor(/*x=*/34,/*y=*/78);
  screen.print("(Realtime Price)");

  screen.setTextSize(1);
  screen.setFont(&FreeMono18pt7b);
  screen.setCursor(/*x=*/65,/*y=*/135);
  screen.print("$");

  screen.setTextSize(1);
  screen.setFont(&FreeMono18pt7b);
  screen.setCursor(/*x=*/85,/*y=*/135);
  screen.print(nano_usd);

  screen.setTextSize(1);
  screen.setFont(&FreeMono18pt7b);
  screen.setCursor(/*x=*/87,/*y=*/170);
  screen.print("USD");
  
  screen.setCursor(/*x=*/49,/*y=*/205);
  screen.setFont(&FreeMono9pt7b);
  screen.setTextSize(1);
  screen.print("coingecko.com");
  delay(20000); // Wait 20s before next round to not get banned on API server

}
}