The Adafruit QT Py CH32V203 is a tiny development board built around the WCH CH32V203G6 — a low-cost RISC-V microcontroller running at up to 144 MHz. In the compact QT Py form factor (Seeed Xiao compatible), it packs USB-C, a STEMMA QT connector, an RGB NeoPixel, and 10 GPIO pins into a board small enough to embed anywhere.

The CH32V203G6 features a single 32-bit RISC-V core with 1-cycle multiply/divide, 10 KB SRAM, 32 KB single-cycle flash, and an additional 224 KB of XIP flash for program or data storage. It includes ADC, timers, USB device, UART, I2C, and SPI peripherals. A reset button and bootloader button let you upload code over USB without needing an external SWD programmer.

Key Features

• CH32V203G6 RISC-V Core – 144 MHz, 32-bit with 1-cycle multiply/divide
• 32 KB + 224 KB Flash – 32 KB single-cycle flash plus 224 KB XIP flash for program/data
• 10 KB SRAM – On-chip memory
• USB-C Connector – Native USB device support; upload code over USB
• STEMMA QT / Qwiic Connector – Plug-and-play I2C for sensors and accessories
• RGB NeoPixel LED – Built-in addressable LED
• 10 GPIO Pins – ADC on all pins, plus hardware UART, SPI, and I2C
• 3.3 V Regulator – AP2112 with 600 mA peak output
• Reset & Bootloader Buttons – Enter USB ROM bootloader without external programmer
• Seeed Xiao Compatible – Same size and pinout with castellated pads for surface mounting
• SWD Pads – On the bottom for advanced debugging

Also Consider

• QT Py RP2040 – Dual-core ARM Cortex-M0+ with CircuitPython support
• QT Py ESP32-S2 – Wi-Fi enabled with CircuitPython and Arduino support
• QT Py ESP32-S3 – Wi-Fi + BLE with 2 MB PSRAM
• QT Py SAMD21 – ARM Cortex-M0+ with full CircuitPython support

Ideal For

• Exploring the RISC-V CH32 ecosystem
• Low-cost USB device projects
• Compact embedded designs with castellated pads
• Developers comfortable with Makefiles and command-line toolchains

Resources

• Adafruit QT Py CH32V203 Learning Guide