This version of FM radio with TEA5767 with digital volume use Arduino Uno development board instead Arduino Mega like in previous artilce.
Digital volume in 15 steps is made with MCP4261-502E/P dual digital potentiometer who work as real potentiometer (logarithmic style)…
TEA5767 FM Radio With Digital Volume control – [Link]
The TEA5767 radio IC is not available at the two largest electronic parts distributors in North America. It might not be made anymore.
They are readily available on eBay though and there is where I bought mine.
http://www.ebay.com/itm/TEA5767-FM-Stereo-Radio-Module-for-Arduino-76-108MHZ-With-Free-Cable-Antenna-/221944971609?hash=item33acf38159:g:c1MAAOSwZVhWTXJZ
works very well too 🙂 and also dirt cheap.