TinyS3[D] ESP32-S3 by Unexpected Maker

Overview

The TinyS3[D] is the smallest member of Unexpected Maker's [D]-series, fitting the power of the ESP32-S3 into the compact TinyPICO form factor — the same footprint as the original TinyPICO and TinyS2. Despite its tiny size, it carries both the dual-core Xtensa LX7 processor at 240MHz and 8MB of QSPI PSRAM, making it one of the most capable ultra-compact ESP32-S3 boards available.

The [D] designation brings two key hardware upgrades over earlier TinyS3 revisions: a dual antenna system combining an onboard high-gain 3D PCB antenna with a u.FL connector for an external antenna, switchable at runtime through an RF control pin; and a dedicated I2C battery fuel gauge for accurate LiPo state-of-charge readings. These additions make the TinyS3[D] well-suited for space-constrained portable and wearable applications that still demand robust wireless performance.

With 8MB of flash and 8MB of PSRAM on an 8MB + 8MB configuration, the TinyS3[D] provides ample storage and dynamic memory for CircuitPython applications even at this reduced size. A total of 17 GPIO pins are broken out, the board includes a low-power RGB LED (visible with dramatically reduced current for deep-sleep awareness), and the USB-C connector provides native USB CDC and USB Serial JTAG for programming and debugging. LiPo battery charging via a 700mA 3.3V LDO completes the power management picture.

The TinyS3[D] ships with CircuitPython and a UF2 bootloader. It supports Arduino (2.0.3+), ESP-IDF, and MicroPython, and is pin-compatible with TinyPICO and TinyS2 designs. Unexpected Maker provides open-source schematics on GitHub and full documentation at esp32s3.com.