Sending a simple audio signal to car stereo via UNO

Other Hardware Audio
1

Hello, I am working on a project in which i am using a bluetooth module for wireless communication between the arduino UNO & a car stereo system w/ bluetooth compatibility. I must use the module to send an audio signal, which is meant to be an alarm. I did not have much knowledge about wireless communication prior to starting the project, and am facing some challenges trying to understand the interface between the MC and module.

Can anyone suggest how i can generate an analog audio signal in the MC, and then send that through a communication line (SPI, OR USART, OR PSM?) to the bluetooth module?

2

Tone library will create audio output, or you can write some simple code

if (digitalRead(buttonX) == LOW){
startTime = millis();
while ((millis() - startTime) <=5000){ // 5 second alarm
digitalWrite (audioOutPin, HIGH);
delayMicroseconds (1000); // 1mS each high/low = 500 Hz
digitalWrite (audioOutPin, LOW);
delayMicroseconds(1000);
}

You can feed that into this to send to the car's bluetooth receiver
http://www.parts-express.com/avantree-priva-multipoint-wireless-bluetooth-audio-transmitter-aptx-low-latency--320-344
or find a similar device

3

This one's a little less costly even

4

Thanks a lot for the reply. I am planning to use the RN-52 Bluetooth module to send the audio to the car stereo system. What arduino functions will be required to send the audio to a digital pin?

Also, this alarm will only be sent when sensor values which are passed through analog inputs are out of a normal range (temperature, humidity). So, do i need special interrupt function in order to send the alarm to the pin or is it possible by using "if' statements?