HC-05 cannot receive data from arduino

Hello! I am trying to build an app to send movement commands to a robot with bluetooth and receive a signal if a PIR sensor has detected movement and display a notification. Right now I am just trying to test the bluetooth communication. The transfer of data from the phone to arduino works well, but the data I am trying to send through the serial monitor to the phone doesn't seem to be received. Here is the app I currently have:

I don't really care about what is received, that's why I have a label that should be set to the number of bytes just for debug, but nothing is happening. I just care about the notification. And here is the arduino code I am using for testing:

#include <SoftwareSerial.h>

// Create a SoftwareSerial object
SoftwareSerial bluetooth(2, 3); // RX, TX

void setup() {
  // Begin serial communication with the Arduino IDE (Serial Monitor)
  // Begin serial communication with the Bluetooth module
  // Print a message to the serial monitor
  Serial.println("Bluetooth Test");

void loop() {
  if (bluetooth.available()) {
    // Read a character from the Bluetooth module
    char c = bluetooth.read();
    // Print the character to the serial monitor
  // Check if data is available to read from the Serial Monitor
  if (Serial.available()) {
    // Read a character from the Serial Monitor
    char c = Serial.read();
    // Send the character to the Bluetooth module

I tried to set the delimiter byte of the bluetooth client to 10 to stop at a newline but it didn't do anything. I would need any ideas and I appreciate any help! Thank you!

Try a Bluetooth terminal app from the play store to factor out your app

I tried the same with a play store app, the transmission works fine but I cannot receive anything. Would that mean there is a problem with the bluetooth module?


Recheck wiring, and look for tx/rx misconfigurations.

Well.. I checked it all everything seems to be fine. Rx pin of hc05 is on pin 3 of arduino and Tx is on pin 2. Vcc works as I have other components on that line that work just fine (and transmission to arduino works) and the ground is connected. Is there any possibility other than the module being broken?

If it's worth mentioning, when sending commands in the AT command mode the bluetooth responds to them so the transmission works then.

Nevermind.. I said that because it did it earlier but apparently now AT doesn't work either. I read now that Rx and Tx should get 3V3 with a voltage divisor and I connected them directly at arduino pins which i believe give 5V. Is it possible that it affected them?

You'll have to wait for one of our hardware guys to answer that for you.