Miniature Watch-Style FM RADIO

Radio has remained one of the most enduring and essential communication devices, retaining its relevance to this day. Its evolution—from large, bulky units to compact, portable forms—has been remarkable.

- ASHWINI KUMAR SINHA

This device pushes that evolution further, delivering one of the smallest wearable and portable FM radios to date.

Two innovative versions have been developed: a watch-style wearable FM radio and another compact enough to fit inside an earbud. The watch-style version is built around the IndusBoard Coin V2, which measures just 3cm in diameter. It features a 3cm GC9A01 round LCD display with a touch interface powered by the CST816S touch driver IC, as illustrated in Fig. 1.

The required components for assembling the device are listed in the Bill of Materials table.

The second version is intended to function as a compact FM radio housed directly within an earbud. A prototype of this version will be described in another article soon.

The objective of these designs is to make the FM radio as small and wearable as possible, whether integrated into an earbud or embedded seamlessly behind the IndusBoard. To achieve the latter, the RDA5807M FM stereo radio module has been selected. This article describes the design of the touch display-based compact FM radio. The next article will explore the second version that fits inside an earbud.

Software

To begin, several essential libraries must be installed via the Arduino Library Manager, accessible from the tools menu. These include: TFT_eSPI for managing the display, CST816S for touchscreen control, RDA5807M for FM radio functionality, and TimeLib for handling clock features.