LILYGO T-Dongle S3 Plus adds microphone, IR, and optional ATECC508A security chip

LILYGO has released the T-Dongle S3 Plus, expanding its USB-stick-shaped ESP32 development board lineup with new peripherals and an optional hardware security chip. The device pairs a dual-core Xtensa LX7 processor with 16MB Quad-SPI flash, 8MB OPI PSRAM, and a 0.96-inch ST7735 display, while adding a PDM microphone on GPIO8/GPIO9, an infrared transmitter on GPIO7, and optional Microchip ATECC508A cryptographic support via I2C.

The ATECC508A provides ECDSA, ECDH, and hardware random-number generation, though developers must program its configuration themselves with the caveat that some settings lock permanently. The board maintains the integrated USB Type-A connector, BOOT button, and Qwiic-style serial connector from prior models, with software support through Arduino IDE, PlatformIO, and MicroPython. Example code and configuration resources are available through LILYGO's existing GitHub repository for the T-Dongle S3 series.

Peripheral additions and security architecture

• PDM microphone interface: Audio input is provided through a pulse-density modulation microphone connected to GPIO8 (clock) and GPIO9 (data), enabling voice capture and embedded audio applications without external ADC hardware.
• Infrared transmission: A dedicated IR transmitter on GPIO7 allows the device to function as a universal remote or IR control endpoint, expanding use cases beyond the prior display-and-storage focus.
• ATECC508A security module: The optional Microchip chip adds hardware-accelerated ECDSA signing, ECDH key agreement, and RNG via I2C on GPIO10/GPIO11, but ships unconfigured and requires careful one-time programming as some fuses are irreversible.
• Memory configuration: 16MB Quad-SPI flash and 8MB OPI PSRAM require explicit setup in development environments, with LILYGO providing board-specific configuration templates for the non-standard memory sizes.
• Display and feedback: The retained 0.96-inch 80×160 ST7735 IPS LCD and APA102 RGB LED provide visual output, while the Qwiic-style connector defaults to serial communication for expansion modules.

Why it matters

The T-Dongle S3 Plus lowers the barrier for building secure, audio-capable IoT prototypes by integrating a hardware trust anchor and PDM microphone in a sub-$20 USB form factor, though developers must weigh the ATECC508A's configuration complexity against its cryptographic guarantees. For the open-hardware community, LILYGO's continued publication of schematics and GitHub-hosted example code sustains a model of commercially available yet documentable embedded devices that bridge hobbyist and production use.