How to find nearby Bluetooth devices

[Mithun_K_Das]

We know that we can scan nearby Bluetooth devices through our phones. But how we can scan nearby available Bluetooth devices using Bluetooth modules such as HC-05/06 or JDY-08 etc?

Thanks in advance.

--- Updated Apr 3, 2022 ---

I used this code after reading that the HC05 can find the scan list.

#include <SoftwareSerial.h>

SoftwareSerial Bluetooth(6, 5);
String readstr;
void setup()
{
  Serial.begin(9600);
  Bluetooth.begin(38400);
  // Bluetooth.begin(115200);
  Bluetooth.print("AT+ROLE=1\r\n"); delay(1000);
  Bluetooth.print("AT+CMODE=1\r\n"); delay(1000);
  Bluetooth.print("AT+INIT\r\n"); delay(1000);
  Bluetooth.print("AT+IAC=9e8b33\r\n"); delay(1000);
  Bluetooth.print("AT+CLASS=1f1f\r\n"); delay(1000);
  Bluetooth.print("AT+INQM=1,2,20\r\n"); delay(1000);

  Serial.println("BT Scan result: ");
}

void loop()
{


  Bluetooth.print("AT+INQ\r\n");

  delay(10);
  while (Bluetooth.available())
  {
    delay(10);
    char c = Bluetooth.read();
    readstr += c;
  }
  if (readstr.length() > 0)
  {
    Serial.print("BT response:");
    Serial.println(readstr);
    readstr = "";
    delay(3000);
  }
  delay(2000);

}

But there is nothing except just 'OK' in return

 

[BradtheRad]

I believe the advice is to use Bluetooth over short distances. Distant devices may not be detected.

Even with nearby devices Bluetooth seems fussy. I have an iPhone and Macintosh. They recognize each other but that's all. I have never succeeded in transferring data. Usually I must make several attempts, discarding and reconnecting. (The passcode works.) Nor has cable USB hookup ever succeeded for me.

Those are my only Bluetooth devices. Occasionally the list includes a device from a nearby apartment.

I'd appreciate a helpful verbose report onscreen, telling me how far Bluetooth contact progressed, and what is the hangup. I don't understand why Macintosh and Windows keep it obscure.

Can you dig further internally to find progress reports... such as what channel frequencies it tries, baud rates, signal strengths?

 

[Aussie Susan]

I've not used the devices you mention, nor used the ATxxx codes, but all Bluetooth devices will advertise in whatever manner the device maker wishes. (Devices connected to a power supply generally advertise continuously, while battery powered devices tend to advertise in bursts to conserve power.)
What @BradtheRad is probably seeing on iPhones and Macs is probably a filtered set of advertisement packets.
On my iPhone/iPad I use 'BLE Scanner' or 'CySmart' that show all of the advertising devices (and their RSSI values) although many show up as 'N/A' (because the device is not advertising its name - there is probably something else in the packet that is being used to identify it). There are other apps that scan for Bluetooth devices around.
Susan