18650 Battery Holder with Charger and 5V Step-up Module (USB-C)

/*
 * ==================================================================
 *  Generated by Codey.online  —  https://www.codey.online
 * ==================================================================
 *  Project   : Powering Arduino Uno with 18650 Battery Shield
 *  Board     : Arduino UNO (arduino:avr:uno)
 *  Parts     : 18650 Battery Shield with USB-C Charger and 5V Boost Converter
 *  Libraries : none (built-in)
 *
 *  Codey Online is an AI-powered browser IDE for Arduino and ESP32.
 *  Describe your project and Codey writes the code, draws the wiring
 *  diagram and uploads it to your board, straight from the browser.
 *  This code is free to use, modify and share, without warranty.
 * ==================================================================
 */

// Powering Arduino Uno from 18650 Battery Shield with 5V Boost Converter

const int LED_PIN = 13;

void setup() {
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(115200);
  
  Serial.println(F("18650 Battery Shield 5V Power Demo"));
  Serial.println(F("Arduino Uno is running from the shield's 5V UPS output."));
}

void loop() {
  // Blink onboard LED to visually confirm operation while on battery
  digitalWrite(LED_PIN, HIGH);
  delay(500);
  digitalWrite(LED_PIN, LOW);
  delay(500);

  Serial.println(F("Operating normally on battery power..."));
}

/*
 * ==================================================================
 *  Generated by Codey.online  —  https://www.codey.online
 * ==================================================================
 *  Project   : ESP32 18650 UPS Battery Shield Demo
 *  Board     : ESP32 DEVKIT V1 (esp32:esp32:esp32doit-devkit-v1)
 *  Parts     : 18650 Battery Shield with USB-C Charger and 5V Boost Converter
 *  Libraries : none (built-in)
 *
 *  Codey Online is an AI-powered browser IDE for Arduino and ESP32.
 *  Describe your project and Codey writes the code, draws the wiring
 *  diagram and uploads it to your board, straight from the browser.
 *  This code is free to use, modify and share, without warranty.
 * ==================================================================
 */

const int LED_PIN = 2;
unsigned long lastReport = 0;

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);

  Serial.println("ESP32 powered by 18650 Battery Shield!");
  Serial.println("Running portable test...");
}

void loop() {
  // Blink the onboard LED
  digitalWrite(LED_PIN, HIGH);
  delay(500);
  digitalWrite(LED_PIN, LOW);
  delay(500);

  // Report status every 2 seconds
  if (millis() - lastReport >= 2000) {
    lastReport = millis();
    unsigned long seconds = millis() / 1000;
    Serial.print("Battery-powered uptime: ");
    Serial.print(seconds);
    Serial.println(" s");
  }
}