HC-05 Bluetooth module stopped working.

I was using a HC-05 Bluetooth module for a home automation project. The module worked fine until sometime ago, it just stopped abruptly. I have checked the connections and its all good. It pairs to my Android phone and even connects to a Bluetooth terminal app, but doesn't seem to receive anything, nor transmit. The LED on the module blinks just fine as before, though.

I ordered an other module, hopelessly. It takes a couple of week to get to me. Anything I can do to save this module in the mean time would be greatly appreciated. :drooling_face:

Anjanbabu: The LED on the module blinks just fine as before, though.

This is not "just fine". If it blinks, it isn't connected.

IF you really are establishing a connection with the right procedure on the Android, with proper confirmation, and THEN you still see a blinking LED, it could be that you are instantly losing the connection, which suggests it might be a power problem.

The LED on the module used to blink continuously when the connection was lost and blink twice every two seconds when successfully connected to a device. It used to work fine then.

OK, is that the little 6-pin module, or are you referring to a shield? I don’t actually have the LED connected on my HC-05.
Your problem could still be power.

6pin module. What sort of power issue are you referring to? My module is rated for 3.3 - 6v and I'm sure the 5v supply from Arduino Uno is stable.

OK, I assume it is a JY-MCU module or the like, and I will solder up the LED connection on mine. I am only speculating on the power because I can't see another explanation, and I'm talking about current, not volts, as the module is a bit of a power hog. Are you supplying power through a USB cable or a wall wart.?

Another thing worth mentioning is your computer's USB port. Voltage might vary, and especially if you're using an unofficial USB port such as those ones: https://www.mac-usb-serial.com - it just happened to me and was fixed when using another power source. The symptom in my case was : blinky / stable for 5 seconds then off. Restarting Arduino IDE / computer fixes it.

Did you connect the Arduino directly to the BT RX pin?

I had someone report a similar problem and it turned out they had damaged the RX pin by connecting to 5V. The damage happened over time not straight away.