Overview
The new XIAO ESP32‑C5 arrives as a compact development board that packs dual‑band Wi‑Fi 6, Bluetooth 5, and optional Zigbee/Thread radios. Its RISC‑V core delivers efficient processing while the tiny footprint keeps it suitable for desk‑top projects. In this review I pair the board with a set of Grove sensors to illustrate real‑world capability.
The board exposes fourteen GPIO pins that match the standard Grove connector layout, making plug‑and‑play wiring straightforward. An on‑board OLED display provides immediate visual feedback, while the integrated battery charger lets the device run for days on a single cell. The layout mirrors earlier XIAO models, so existing codebases transfer with minimal changes.
Hardware Features
Dual‑band Wi‑Fi support includes both 2.4 GHz and 5 GHz bands, enabling faster data rates in crowded environments. The Bluetooth 5 radio adds low‑energy connectivity for wearables and peripherals, and the optional Zigbee and Thread stacks broaden mesh networking options. All radios share a common antenna, reducing board complexity.
The RISC‑V processor runs at up to 240 MHz and pairs with 520 KB of SRAM, offering ample headroom for sensor fusion tasks. Flash storage of 4 MB accommodates firmware and data logs without external memory. Power pins are clearly labeled, allowing easy integration of the Grove expansion board that carries the OLED screen.
Sensor Integration
The included Digital Infrared Temperature sensor reports ambient temperature and can measure the heat of objects placed within its field of view. Data updates occur every second, and the OLED screen can render both numeric values and simple graphs. Calibration is handled automatically by the library, so no manual offset is required.
The Piezo Vibration sensor detects mechanical shocks and can trigger alerts when thresholds are crossed. Coupled with the Gesture PAJ7620U2 module, the board can recognize swipes, taps, and proximity gestures, enabling touch‑free control of the display. Both sensors feed into a shared event loop that keeps the main program responsive.
Power Management
The XIAO ESP32‑C5 includes a low‑power sleep mode that reduces current draw to under 5 µA, extending battery life when the device is idle. Wake‑up can be triggered by the Button input, a timer, or a sensor event, providing flexible power‑saving strategies. The on‑board PMIC manages charging and protects against over‑discharge.
Testing with a 500 mAh Li‑Po cell showed more than 48 hours of continuous operation while sampling temperature and vibration at one‑second intervals. When the display is turned off, runtime increases to over a week in deep‑sleep mode. These results demonstrate that the board is suitable for remote monitoring without frequent battery swaps.
Software Setup
Development begins in the Arduino IDE, where the ESP32 core is installed via the board manager. Required libraries for the Grove temperature, vibration, and gesture modules are added through the library manager, simplifying code inclusion. Example sketches compile and upload in under a minute.
Flashing the firmware uses the built‑in USB‑C connector, eliminating the need for external programmers. After upload, the board enumerates as a serial device, allowing real‑time logging of sensor values. The process is repeatable and works on Windows, macOS, and Linux without additional drivers.
Practical Use Cases
One practical implementation is a desk‑side ambient monitor that shows temperature, vibration alerts, and gesture‑controlled menu navigation on the OLED. By pressing the Button, the user can toggle between data screens, while a gesture swipe left or right cycles through historical trends. This setup provides immediate feedback without requiring a separate computer.
Another scenario involves integrating the board into a small enclosure that reports environmental data to a home‑automation hub via Wi‑Fi. The optional Zigbee interface allows the same hardware to join a mesh network, making it adaptable to different smart‑home standards. The flexibility of the ESP32‑C5 means the same prototype can evolve into a production‑ready node.