# Adafruit QT Py ESP32-C3

> Tiny RISC-V ESP32-C3 dev board in the QT Py / Seeed XIAO footprint with 4 MB flash, WiFi, BLE 5 with Mesh, STEMMA QT, 13 GPIO, 5 ADC inputs, and USB-C — no native USB.

## Quick Facts

- **Brand:** Adafruit
- **Board Type:** dev-board
- **Price:** ~$9.95
- **Product Readiness:** developer
- **CPU:** RISC-V single-core @ 160 MHz (ESP32-C3)
- **CPU Architecture:** RISC-V 32-bit
- **CPU Cores:** 1
- **RAM:** 400 KB SRAM
- **Flash:** 4MB
- **Power:** 5V
- **Operating Voltage:** 3.3V
- **Dimensions:** 22 × 17.8 × 5.7 mm
- **Weight:** 2.1 g
- **Antenna:** built-in PCB antenna

## Connectivity

- **Wifi:** 2.4GHz 802.11 b/g/n
- **Bluetooth:** Bluetooth 5.0 + Mesh

## Open Source

- **Firmware:** Yes
- **Schematics:** Yes
- **PCB Layout:** Yes

## Compatible Firmware

circuitpython, micropython, arduino, esp-idf

## Use Cases

- iot
- smart-home
- wearable

## Components

- **ESP32-C3** (mcu): Espressif ESP32-C3 single-core 160 MHz RISC-V with 4 MB Flash, 400 KB SRAM, WiFi, and BLE 5 with Mesh. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32-c3_datasheet_en.pdf&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export)

## Protocols

- **I2C**: SDA: GPIO5 (breakout) / GPIO1 (STEMMA QT), SCL: GPIO6 (breakout) / GPIO0 (STEMMA QT)
- **SPI**: SCK: GPIO6, MOSI: GPIO7, MISO: GPIO8
- **UART**: TX: GPIO20, RX: GPIO21
- **PWM**
- **I2S**

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| GPIO2 | A0 / NeoPixel Data (shared) | ADC | adc, digital-input, digital-output, pwm |
| GPIO3 | A1 — Analog Input (ADC1_CH3) | ADC | adc, digital-input, digital-output, pwm |
| GPIO4 | A2 — Analog Input (ADC1_CH4) | ADC | adc, digital-input, digital-output, pwm |
| GPIO5 | A3 / SDA — Analog Input / I2C Data (shared) | I2C | adc, digital-input, digital-output, pwm |
| GPIO6 | SCK / SCL — SPI Clock / I2C Clock (shared) | SPI | digital-input, digital-output, pwm |
| GPIO7 | MOSI / D1 — SPI Data Out | SPI | digital-input, digital-output, pwm |
| GPIO8 | MISO / D0 — SPI Data In / NeoPixel Power | SPI | digital-input, digital-output, pwm |
| GPIO0 | SCL — STEMMA QT I2C Clock | I2C | digital-input, digital-output, pwm |
| GPIO1 | SDA — STEMMA QT I2C Data | I2C | digital-input, digital-output, pwm |
| GPIO20 | TX — UART0 Transmit | UART | digital-input, digital-output, pwm |
| GPIO21 | RX — UART0 Receive | UART | digital-input, digital-output, pwm |

## Available Software

- **[CircuitPython](https://openhardware.directory/r?to=https%3A%2F%2Fcircuitpython.org%2Fboard%2Fadafruit_qtpy_esp32c3%2F&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export)**
- **[Arduino ESP32](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fespressif%2Farduino-esp32&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export)**

## Description

## Overview

The Adafruit QT Py ESP32-C3 brings the RISC-V ESP32-C3 microcontroller into the compact QT Py / Seeed XIAO form factor at 22 × 17.8 mm. Despite being the most affordable QT Py WiFi variant, it includes both WiFi (2.4 GHz) and Bluetooth Low Energy 5.0 with Mesh support — making it the smallest and cheapest board in the QT Py line with full BLE.

The ESP32-C3 uses a 32-bit single-core RISC-V architecture at 160 MHz, which is more power-efficient than the Xtensa cores in the ESP32 family. This makes the QT Py ESP32-C3 a strong choice for always-on BLE beacons or sensors that need to run for months on a small battery. Deep sleep current sits at around 300 µA and light sleep at 500 µA.

A STEMMA QT / Qwiic connector provides instant I2C sensor integration, and five 12-bit ADC inputs (A0–A3, SDA) cover typical analogue sensing needs. PWM is available on any pin. Unlike the ESP32-S2/S3 variants, the C3 uses a USB-to-UART bridge rather than native USB, so it is not natively HID-capable but is fully compatible with the Arduino IDE without any extra setup.

Hardware I2S enables audio input/output, and a hardware UART plus SPI bus are exposed on the breakout pads. The board is compatible with CircuitPython, MicroPython, and Arduino. A NeoPixel RGB LED with power-control pin, Reset button, and GPIO 9 bootloader button are included.

## Where to Buy

- [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F5405&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export) — 9.95

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F5405&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit-QT-Py-ESP32-C3-PCB&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export)
- [learn guide](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fadafruit-qt-py-esp32-c3&ref=openhardware.directory&product=adafruit-qt-py-esp32-c3&source=md-export)

## Tags

`esp32-c3`, `risc-v`, `qt-py`, `stemma-qt`, `circuitpython`, `wifi`, `ble`, `tiny`, `xiao-compatible`

## Images

![Adafruit QT Py ESP32-C3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-qt-py-esp32-c3/940d52b25325.jpg)
![Adafruit QT Py ESP32-C3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-qt-py-esp32-c3/0518d657b4e2.jpg)
![Adafruit QT Py ESP32-C3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-qt-py-esp32-c3/bb792551c357.jpg)

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