18650 Battery Shield with USB-C Charger and 5V Boost Converter

// Canonical beginner example for using the 18650 Battery Shield with USB-C Charger
// and 5V Boost Converter as a 5V power source for an Arduino Uno.
//
// Wiring:
// Arduino 5V  -> UPS_OUT_POS
// Arduino GND  -> UPS_OUT_NEG
//
// This sketch just confirms the board is powered by printing a message over Serial.

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ; // Wait for Serial Monitor on boards that need it; harmless on Uno.
  }

  Serial.println("18650 Battery Shield connected as a 5V power source.");
  Serial.println("If the shield is powered and the boost converter is on, the Arduino should run normally.");
}

void loop() {
  Serial.println("Arduino Uno powered by the battery shield.");
  delay(2000);
}