Audio out to bluetooth

There are plenty of bluetooth chips in the market that can easily output an audio signal. The problem with this chips is that they work with digital audio signals, normally I2S or SPDIF protocols.

There are also some other options, like use an integrated bluetooth transmitter with analog input, if you type the words "bluetooth transmitter 3.5mm" on ebay or amazon you will get plenty of examples for around £10. I never played with them before but I am sure that they are fun (you will need a 3.5 to 1/4 adapter).



This one from amazon features:

3.5mm Bluetooth A2DP Stereo Audio Adapter Dongle Transmitter 4 TV PC MP3 Walkman
Manufacturer: Jazooli Brand: Jazooli

• This adapter will allow you to play music via your non bluetooth device wirelessly to any Bluetooth Speaker
• Built in rechargeable lithium battery with up to 8 hours playing time.
• Play your favourite songs wirelessly in your car and from a device up to 15 metres away.
• Will work with all Bluetooth speakers.

There is also the option of looking for some chip or development kit in Mouser and try to design your own subsystem from the very basics, but I dont have much experience doing that.