Pairing 2 Arduino Nano 33 BLE over Bluetooth

[stiglitz03]

The project I am looking to make is to have 1 Arduino Nano 33 rev2 BLE labeled Remote (Central) scan and connect to another Arduino Nano 33 BLE rev2 labeled Base (Peripheral). Once connected, a button on Remote can trigger an event on the Base. In my coding, I was successful in having Remote scan for Base, but the issue I keep having is I can't get the 2 boards to connect/pair, or for the few times I was able to get them to connect/pair, the connection is lost after 3 seconds and they will disconnect. How can I make the connection stick? Is there maybe another library I should be using with ArduinoBLE? If it is not clear as to the LED on pin 12, its to have a visual that a connection has been made. Thank you for your time.

Remote Code:

#include <ArduinoBLE.h>

bool deviceFound = false; // Flag to track if the device is found

void setup() {
  Serial.begin(9600); // Start serial monitor
  while (!Serial); // Wait for serial to connect
  Serial.println("Serial Monitor is working");

  // Set pin 12 as an output for the LED
  pinMode(12, OUTPUT);
  digitalWrite(12, LOW); // Ensure the LED is initially off

  // Start the Bluetooth Low Energy (BLE) device
  if (!BLE.begin()) {
    Serial.println("Starting Bluetooth® Low Energy module failed!");
    while (1);
  }

  Serial.println("Starting Bluetooth® Low Energy module is online!");
  Serial.println("Searching for Base...");
}

void loop() {
  // Start scanning for BLE devices with the name "Base"
  BLE.scanForName("Base");

  // Check if a device is found
  BLEDevice foundDevice = BLE.available(); // Retrieve the first available BLE device

  if (foundDevice && !deviceFound) {
    // Check if the found device's name is "Base"
    if (foundDevice.localName() == "Base") {
      Serial.print("Found: ");
      Serial.println(foundDevice.localName());

      // Set the flag to true so it doesn't print again
      deviceFound = true;

      // Attempt to connect to the found device (which will handle pairing automatically)
      Serial.println("Attempting to connect to Base...");
      bool connected = foundDevice.connect();  // Attempt the connection

      if (connected) {
        Serial.println("Connected to Base!");
        digitalWrite(12, HIGH);  // LED on
      } else {
        Serial.println("Failed to connect to Base. Retrying...");
        delay(2000);  // Wait before retrying connection
      }
    }
  }

  // If device is not found, make sure LED is off
  if (!deviceFound) {
    digitalWrite(12, LOW);  // LED off
  }

  // Add a short delay to avoid flooding the serial monitor
  delay(1000);
}

Remote Serial Monitor Printout:
Serial Monitor is working
Starting Bluetooth® Low Energy module is online!
Searching for Base...
Found: Base
Attempting to connect to Base...
Failed to connect to Base. Retrying...

Base Code:

#include <ArduinoBLE.h>

void setup() {
  Serial.begin(9600);  // Start serial monitor
  while (!Serial);     // Wait for serial to connect
  Serial.println("Serial Monitor is working");

  // Initialize BLE
  if (!BLE.begin()) {
    Serial.println("Starting Bluetooth® Low Energy module failed!");
    while (1);  // Stay here if BLE initialization fails
  }

  Serial.println("Starting Bluetooth® Low Energy module is online!");

  // Set the local Bluetooth name to "Base"
  const char* localName = "Base";  // Local name as a C-string
  BLE.setLocalName(localName);     // Set the Bluetooth localName

  // Create a service
  BLEService myService("180D");  // UUID needed for iPhone to see advertising name for verification that advertising is working
  BLE.setAdvertisedService(myService); // Advertise the service

  // Print localName to Serial Monitor, for debugging to verify correct localName is being advertised
  Serial.print("Advertising Local Name: ");
  Serial.println(localName); // Print the advertising name (local name)

  // Start BLE advertising
  BLE.advertise();  // Start advertising over Bluetooth
  Serial.println("Advertising... Waiting for Remote to connect");
}

void loop() {
  // Keep the BLE stack running
  BLE.poll();
}

Base Serial Monitor Printout:
Serial Monitor is working
Starting Bluetooth® Low Energy module is online!
Advertising Local Name: Base
Advertising... Waiting for Remote to connect