ESP32 Forum

Posted: **Fri Mar 08, 2024 12:11 pm**

Hello everyone,

I have a project called tracking robot. In this project, I want to use ESP32 as a BLE server and connect my phone to ESP32. In this link, I want to take the RSSI values and convert them to distance. According to these distance values, I plan to control my DC Motor via the pins connected to my motor driver card. I wrote the following code without using BLE Server, but I can't translate it into a BLE server application. Can you help me with this?

Code: Select all

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

BLEScan* pBLEScan;
BLEAddress DeviceAddress("60:d0:39:cc:8d:5a");
bool deviceFound = false;
float filteredRSSI = -50;
float alpha = 0.25; 

class MyAdvertisedDeviceCallbacks : public BLEAdvertisedDeviceCallbacks {
  void onResult(BLEAdvertisedDevice advertisedDevice) {
    if (advertisedDevice.getAddress() == DeviceAddress) {
      int rssi = advertisedDevice.getRSSI();
    
      filteredRSSI = alpha * rssi + (1.0 - alpha) * filteredRSSI;
      float distance = pow(10, ((-64- filteredRSSI) / 27.0));

      Serial.print("Filtered RSSI Value: ");
      Serial.print(filteredRSSI);
      Serial.print("\tReal RSSI Value: ");
      Serial.println(rssi);
      Serial.print("Distance: ");
      Serial.println(distance);

      deviceFound = true;
    }
  }
};

void setup() {
  Serial.begin(921600);
  // Initialize BLE
  BLEDevice::init("ESP32_BLE_Client");

  // Start BLE scan
  pBLEScan = BLEDevice::getScan(); // Get BLEScan object
  pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
  pBLEScan->setInterval(100); // Set scan interval to 100ms
  pBLEScan->setWindow(99);    // Set scan window to 99ms
  pBLEScan->setActiveScan(true); // Use active scanning
  Serial.println("Scanning started...");
}

void loop() {
  // You can perform other tasks during scanning
  pBLEScan->start(1, false); // Scan for 1 second

  if (!deviceFound) 
  {
    Serial.println("Searching for BLE device...");
  } 
  else 
  {
    deviceFound = false; // Reset for the next scan
  }
}

ESP32 Forum

Getting RSSI Value from client which connected to ESP32 BLE Server

Getting RSSI Value from client which connected to ESP32 BLE Server