Adafruit QT Py S3 ESP32-S3 WiFi Dev Board w/ 2MB PSRAM & STEMMA QT

The board is fully supported in the Arduino IDE using the ESP32 board package, in Espressif's ESP-IDF for advanced features, and in CircuitPython for rapid Python-based development. Use a USB-C cable to connect; it enumerates as a serial COM port for uploading code. The BOOT0 button is used to enter download mode if automatic firmware upload fails. Native USB allows it to also act as a USB mass storage device in CircuitPython for direct file editing.

The 2MB PSRAM (Pseudo Static RAM) provides additional volatile memory for buffering large data sets that exceed the internal 512KB SRAM. It is essential for applications like buffering camera images, audio samples, graphics frames, or machine learning model weights. In Arduino, enable PSRAM in the board configuration menu. In ESP-IDF, use heap_caps_malloc() with MALLOC_CAP_SPIRAM flag. It is not persistent storage; data is lost on power-off.

Yes, you can solder wires to the BAT and GND pads on the back to connect a 3.3V to 6V DC battery pack. The onboard regulator will supply 3.3V. For low-power operation, utilize the ESP32-S3's sleep modes: Light Sleep consumes approximately 2-4mA with RAM retained, while Deep Sleep can reduce current to around 70 microamps, allowing for months of operation on a suitable LiPo battery when waking periodically for measurements.

The STEMMA QT connector provides a 4-pin JST SH socket (VCC, GND, SDA, SCL) for plug-and-play connection of Qwiic or Grove I2C devices. It uses two of the board's GPIOs for I2C, specifically the SDA and SCL lines. The 11 breakout pads give you access to the remaining GPIOs, including the second I2C port, hardware SPI, UART, ADC pins, and capacitive touch inputs. You can use both simultaneously, allowing a sensor on QT and other peripherals on the breakout pins.