XIAO ESP32C6
Tiny ESP32-C6 board by Seeed Studio with USB-C, Wi-Fi 6, BLE, and Thread - ideal for compact and wearable IoT builds.
XIAO ESP32C6 Pinout
14 pins · 2.54 mm pitch
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | D0A0GPIO0LP_GPIO0 | safe | adc · pwm | |
| 2 | 1 | D1A1GPIO1LP_GPIO1 | safe | adc · pwm | |
| 3 | 2 | D2A2GPIO2LP_GPIO2 | safe | adc · pwm | |
| 4 | 21 | D3GPIO21SDIO_DATA1 | safe | pwm | |
| 5 | 22 | D4SDAGPIO22SDIO_DATA2 | safe | i2c · pwm | |
| 6 | 23 | D5SCLGPIO23SDIO_DATA3 | safe | i2c · pwm | |
| 7 | 16 | D6TXGPIO16 | uart | uart · pwm | |
| 8 | - | 5V | power | - | 5V power input/output |
| 9 | - | GND | ground | - | |
| 10 | - | 3V3 | power | - | 3.3V power |
| 11 | 18 | D10MOSIGPIO18SDIO_CMD | safe | spi · pwm | |
| 12 | 20 | D9MISOGPIO20SDIO_DATA0 | safe | spi · pwm | |
| 13 | 19 | D8SCKGPIO19SDIO_CLK | safe | spi · pwm | |
| 14 | 17 | D7RXGPIO17 | uart | uart · pwm |
Start with these
9 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
2 pins · 2 things to knowD6GPIO16 UART0 TX; Flash CS0 (internal-flash models). UART
Default UART0 transmit pin; using it may interfere with serial console or programming.
D7GPIO17 UART0 RX. UART
Default UART0 receive pin; using it may interfere with serial console or programming.
The XIAO ESP32C6 breaks out 14 pins in total: 11 GPIO for your project, with 5V, GND and 3V3 handling power.
For peripherals, I²C is mapped to SDA on GPIO22 and SCL on GPIO23; the SPI bus (MOSI, MISO, SCK) is broken out in full; TX/RX on GPIO16 and GPIO17 cover serial logging and flashing.
On the analog side there are 3 ADC-capable pins for sensors and battery monitoring and PWM on every GPIO.
If you want zero surprises, D0, D1, D2, D3 and 5 more are free of any such role - the safest first picks. 2 of the exposed pins carry boot-time or system duties on the ESP32-C6 (D6 and D7).
Getting started
flash your first firmware in ~2 minutesBoard: XIAO_ESP32C6 USB CDC On Boot: Enabled Flash Size: 4MB (32Mb) Flash Mode: QIO Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS) Upload Speed: 921600
// blink the onboard user LED
void setup() {
pinMode(15, OUTPUT);
}
void loop() {
digitalWrite(15, HIGH); delay(500);
digitalWrite(15, LOW); delay(500);
}[env:xiao-esp32c6]
platform = https://github.com/pioarduino/platform-espressif32/releases/download/stable/platform-espressif32.zip
board = seeed_xiao_esp32c6
framework = arduino
monitor_speed = 115200
upload_speed = 921600seeed_xiao_esp32c6 - or type it after board =.esp32:
board: seeed_xiao_esp32c6
variant: esp32c6
framework:
type: esp-idf
# blink - GPIO15
output:
- platform: gpio
pin: 15
id: led_out
light:
- platform: binary
name: "LED"
output: led_outseeed_xiao_esp32c6 (same ids as PlatformIO).esptool.py --chip esp32c6 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x0 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Good to know
board-specific quirks worth 60 seconds
The XIAO ESP32C6 carries both an onboard ceramic antenna and a U.FL connector, and which one is live is decided by your firmware through an RF switch. Per Seeed's wiki: pull GPIO3 low to enable the RF switch control, then GPIO14 low selects the built-in antenna (the default) and GPIO14 high selects the external U.FL antenna. That makes range a software decision: prototype on the ceramic antenna, and if the device…
The XIAO ESP32C6 carries both an onboard ceramic antenna and a U.FL connector, and which one is live is decided by your firmware through an RF switch. Per Seeed's wiki: pull GPIO3 low to enable the RF switch control, then GPIO14 low selects the built-in antenna (the default) and GPIO14 high selects the external U.FL antenna.
That makes range a software decision: prototype on the ceramic antenna, and if the device ends up in a metal enclosure or far from the access point, solder nothing - just attach an antenna and flip two GPIOs at boot.
If range is disappointing, check you actually selected the antenna that's connected - transmitting on the U.FL setting with no antenna attached gives the worst of both worlds.
Like every ESP32-C6, this board has a third radio beyond WiFi 6 and Bluetooth 5 LE: an IEEE 802.15.4 radio for Zigbee 3.0, Thread, and Matter-over-Thread. Seeed's wiki ships worked Zigbee examples for this exact board, and the general C6 toolchain applies - Arduino via the ESP32 core, ESP-IDF Zigbee/Thread SDKs, and ESPHome with OpenThread support. Combined with the battery circuit below, this is a natural…
Like every ESP32-C6, this board has a third radio beyond WiFi 6 and Bluetooth 5 LE: an IEEE 802.15.4 radio for Zigbee 3.0, Thread, and Matter-over-Thread. Seeed's wiki ships worked Zigbee examples for this exact board, and the general C6 toolchain applies - Arduino via the ESP32 core, ESP-IDF Zigbee/Thread SDKs, and ESPHome with OpenThread support.
Combined with the battery circuit below, this is a natural board for Zigbee/Thread sensors that live on the mesh instead of crowding your 2.4 GHz WiFi.
Like the SuperMini-class boards, the XIAO C6 has no USB-to-serial converter chip - USB-C connects straight to the ESP32-C6's native USB. Two everyday consequences: Serial output: keep Tools → USB CDC On Boot at "Enabled" (arduino-esp32's default for this board), or Serial.print() goes to the UART pins (D6/D7) instead of your serial monitor. Flashing: if the COM port never appears or an upload fails, hold BOOT while…
Like the SuperMini-class boards, the XIAO C6 has no USB-to-serial converter chip - USB-C connects straight to the ESP32-C6's native USB. Two everyday consequences:
- Serial output: keep Tools → USB CDC On Boot at "Enabled" (arduino-esp32's default for this board), or
Serial.print()goes to the UART pins (D6/D7) instead of your serial monitor. - Flashing: if the COM port never appears or an upload fails, hold BOOT while plugging in USB (or while tapping RESET) to force the ROM bootloader, then press RESET after flashing.
A crashed or deep-sleeping sketch takes the USB port down with it - normal for native-USB boards, not a broken board. The BOOT-button trick always recovers it.
Downloads
Free for non-commercial use, credit espboards.dev · License
Board illustration
The bare XIAO ESP32C6 board drawn to scale at 21 × 17.8 mm, with no pin labels on it. Made for slide decks, wiring diagrams and project write-ups where a photo is too busy. Take the scalable SVG for print or editing, the high-resolution PNG to drop straight in, or the transparent PNG when you need it with no background behind it.
Pinout diagram
Every pin on both sides of the board with its functions, drawn by ESPboards from the ESP32-C6 Series Datasheet v1.5 - the same sheet shown at the top of this page. The PNG is a high-resolution image for screens, the SVG is vector so it stays sharp at any size, and the PDF is laid out to print on A4 or Letter.
Yours to use, share and adapt for non-commercial work, as long as you credit espboards.dev - the full terms and ready-made credit lines are here.
Specifications
ESP32-C6 · 21 × 17.8 mm · vs other ESP32 chips →Dimensions
About this board
At 21 × 17.8 mm it's the smallest ESP32-C6 board we've measured.
At its core is the ESP32-C6 - a RISC-V part adding Wi-Fi 6 plus Thread/Zigbee radios.
Expect to pay about $5.20 - less than the ~$10 most ESP32-C6 boards go for.
The small footprint costs pins: 11 GPIO are broken out, versus 22 or so on a full-size board.
Onboard you'll find Zigbee, battery charging via Solder pads, status LEDs (User, Charge) and Reset/Boot buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-C6 boards.
The XIAO ESP32C6 is Seeed Studio's take on the ESP32-C6: a thumbnail-sized (21 x 17.8 mm) board with the C6's full radio set - WiFi 6, Bluetooth 5 LE, and an 802.15.4 radio for Zigbee, Thread, and Matter-over-Thread. Unlike the generic C6 boards in this class, it's a documented, branded product with a thorough wiki behind it.
Two hardware touches set it apart. First, a dual-antenna design: an onboard ceramic antenna plus a U.FL connector, selected at runtime by an RF switch on GPIO14. Second, real battery support: solder pads for a 3.7 V lithium cell with an onboard charging circuit and a charge-status LED.
The chip pairs a 160 MHz RISC-V core with a 20 MHz low-power core, 512 KB SRAM, and 4 MB flash (no PSRAM). Programming runs over USB-C through the C6's native USB - there's no separate serial chip. Seeed also sells a pre-soldered variant with the headers already fitted.
- Supports WiFi 6, Bluetooth 5, and Zigbee
- Ultra-small size (21x17.8 mm)
- Low power consumption with deep sleep support
- Dual antenna - onboard ceramic plus external u.FL, selected via RF switch on GPIO14 (enable with GPIO3 low)
Where to buy
prices are typical street pricesResources
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