BLE_Scan.ino

#include <BLEAdvertisedDevice.h>
#include <BLEDevice.h>
#include <BLEScan.h>

const int PIN = 2;
const int CUTOFF = -60;

void setup() {
  pinMode(PIN, OUTPUT);
  BLEDevice::init("");
}

void loop() {
  BLEScan *scan = BLEDevice::getScan();
  scan->setActiveScan(true);
  BLEScanResults results = scan->start(1);
  int best = CUTOFF;
  for (int i = 0; i < results.getCount(); i++) {
    BLEAdvertisedDevice device = results.getDevice(i);
    int rssi = device.getRSSI();
    if (rssi > best) {
      best = rssi;
    }
  }
  digitalWrite(PIN, best > CUTOFF ? HIGH : LOW);
}

Here's a demo of the Bluetooth proximity sensor in action: https://www.youtube.com/watch?v=azT2rosEo0k

Hi. May I know how to vary the bluetooth detection distance?

Hi. May I know how to vary the bluetooth detection distance?

Change the value of CUTOFF. Currently it's -60 but if you make it further from zero it'll detect from further away and closer to zero will detect closer.

Hi Can you tell me how setup to this up to detect a specific device ID?

Too bad it does not detect classic bluetooth but only BLE devices. Most phones will only emit classic bluetooth IDs

This is great! thanks! Would you know how to set this up to so that I can have a beacon with an ID I specify and have the LED respond to this specific device and not just any BLE device in the area?

Hello, how can I make them detect each other? that is, in a single ESP32 that scans and can additionally behave as a client so that another ESP32 can detect it

Hi,

1. Is it possible to make the node scan and advertise at the same time, or scan and advertise in round robin? Basically I want them to detect each other.
2. How to identify a node. I understand UUID cant be used because its application or service specific. Is there a unique identifier for every BLE chip that can be accessed inside the program as a part of scan result?

Thanks in advance.

hello wybiral,
can you help me out, i am not a arduino coder.
i am stuck at this. In the code, the loop never stops.
I want to trigger 2 relays using BLE and also set
the activetion distance area to 5meters from the esp32 so that it
triggers only when the BLE device is 5mtrs away.when it is detected
i want it to stay on, while running the code the relay switches on and
off every 2 seconds. hope you would fix it for me.
Thanks Anand.
(the code is:)

#include <BLEDevice.h> //Header file for BLE

static BLEUUID serviceUUID("0000fff0-0000-1000-8000-00805f9b34fb");
static BLEUUID charUUID("0000fff0-0000-1000-8000-00805f9b34fb");
String My_BLE_Address = "c1:b4:70:74:fb:66";
static BLERemoteCharacteristic* pRemoteCharacteristic;

BLEScan* pBLEScan;
BLEScanResults foundDevices;

static BLEAddress *Server_BLE_Address;
String Scaned_BLE_Address;

boolean paired = false;
boolean chkConnet = false;

bool connectToserver (BLEAddress pAddress)
{

BLEClient*  pClient  = BLEDevice::createClient();
Serial.println(" - Created client");

// Connect to the BLE Server.
pClient->connect(pAddress);
Serial.println(" - Connected");
BLERemoteService* pRemoteService = pClient->getService(serviceUUID);
if (pRemoteService != nullptr)
{
  Serial.println(" - Found our service");
  return true;
}
else
return false;

pRemoteCharacteristic = pRemoteService->getCharacteristic(charUUID);
if (pRemoteCharacteristic != nullptr)
  Serial.println(" - Found our characteristic");

  return true;

}

class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks
{
void onResult(BLEAdvertisedDevice advertisedDevice)
{
Serial.printf("Scan Result: %s \n", advertisedDevice.toString().c_str());
Server_BLE_Address = new BLEAddress(advertisedDevice.getAddress());
Scaned_BLE_Address = Server_BLE_Address->toString().c_str();
}
};

void setup()
{
Serial.begin(115200);
Serial.println("Project-4");

BLEDevice::init("");
pBLEScan = BLEDevice::getScan();
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());  
pBLEScan->setActiveScan(true); 

pinMode(12, OUTPUT);
pinMode(14, OUTPUT);
}

void loop()
{

foundDevices = pBLEScan->start(3);
Serial.println(chkConnet);
if(chkConnet == false)
{
while (foundDevices.getCount() >= 1)
{
if (Scaned_BLE_Address == My_BLE_Address && paired == false)
{
Serial.println("connecting .....");
if (connectToserver(Server_BLE_Address))
{
paired = true;
Serial.println("ON");
if(chkConnet == false)
{
digitalWrite (12,HIGH);
digitalWrite (14,HIGH);
chkConnet = true;
Serial.println("On");
}
break;
}
else
{
Serial.println("Pairing failed");
break;
}
}
break;
}
}
while (foundDevices.getCount() == 0)
{
Serial.println("**************");
Serial.println(foundDevices.getCount());

  Serial.println("out of range");
  paired = false;
 
  if(chkConnet == true)
  {
  digitalWrite (12,LOW);
  digitalWrite (14,LOW);
  chkConnet = false;
  Serial.println("OFF");
  }
  ESP.restart();
  break;    

}
}

Hi, can you tell me how setup to this up to detect a specific device ID? That is, I only want one Bluetooth device to trigger the reaction

How do I make this ESP device detect all phones?
For some reaon, I do not see 'most' phones.

Hi, can you tell me how setup to this up to detect a specific device ID? That is, I only want one Bluetooth device to trigger the reaction

Same here...

I want to set up a scenario where a relay is triggered for 30 minutes if my iPhone or Apple Watch is detected within a custom proximity range or signal strength. This scenario should only run in the morning when I am sitting in front of my computer. The trigger will switch on an anti-depression lamp for 30 minutes.

Could you please provide me with some tips on how to achieve this? Thank you.

Hi, Can you post the contents of the Puck.js script? Thanks.

This does not compile as it is written. A corrected version would be:

#include <BLEAdvertisedDevice.h>
#include <BLEDevice.h>
#include <BLEScan.h>

const int PIN = 2;
const int CUTOFF = -60;

void setup() {
  pinMode(PIN, OUTPUT);
  BLEDevice::init("");
}

void loop() {
  BLEScan *scan = BLEDevice::getScan();
  scan->setActiveScan(true);
  BLEScanResults &results = *(scan->start(1));
  int best = CUTOFF;
  for (int i = 0; i < results.getCount(); i++) {
    BLEAdvertisedDevice device = results.getDevice(i);
    int rssi = device.getRSSI();
    if (rssi > best) {
      best = rssi;
    }
  }
  digitalWrite(PIN, best > CUTOFF ? HIGH : LOW);
}