In this guide we demonstrate using a Raspberry Pi Model 3B. However, the processing being done is minimal, and actually any model Pi could probably handle this task. A USB port makes connecting the USB audio adapter easy.

The 1.3" PiTFT used is another trade-off. It's pretty small and only provides two buttons for user interaction. But it leaves some of the Pi's GPIO pins available, which are needed for connecting the Si4713's reset line. Also, it has a STEMMA QT connector which makes the I2C connections easy.

Here's a connection diagram of the overall hardware setup.

• Attach the PiTFT to the Pi GPIO header.
• Use the STEMMA QT connector on the PiTFT to connect to power and I2C to the Si4713.
• Connect Si4713 RST to GPIO 26 on the Pi.
• Plug the USB audio adapter into an available USB port on the Pi.
• Connect the USB audio adapter to the Si4713 input using an audio cable.

Here is a list of the various hardware items shown.

The Si4714 is the FM radio transmitter:

For getting good audio out from the Raspberry Pi, a USB audio adapter is used:

To connect the USB audio adapter to the FM radio, a 3.5mm stereo plug/plug cable is needed. This cable is nothing special and one is often included with various media devices. So check your electronic drawer first - you may already have one.

The 1.3" PiTFT provides status and buttons for user interaction:

The Si4713 is connected to the Pi through the PiTFT's STEMMA QT connector. This cable can be used:

And of course, need a Raspberry Pi. We based this guide on the Pi 3 Model B: