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ESP32-S3 module

The dual-core ESP32 with Wi-Fi, BLE, USB OTG and lots of GPIOs, for cameras, displays and keyboards. WROOM-1 needs the usual 3.3 V, EN and BOOT circuit.

What it does#

The ESP32-S3-WROOM-1 has two Xtensa cores at 240 MHz, up to 16 MB flash and 8 MB PSRAM, and native USB OTG / Serial-JTAG on GPIO19 (D−) and GPIO20 (D+): module pins 13 (USB_D−) and 14 (USB_D+). Up to 36 GPIOs.

What it needs#

  • 3.3 V, at least 500 mA, 10 µF + 100 nF at the module.
  • EN (CHIP_PU): 10 kΩ / 1 µF RC, RESET button; never floating.
  • Strapping pins:
    • GPIO0: weak pull-up; 1 = normal boot, 0 = download. Add a 10 kΩ pull-up and the BOOT button to GND.
    • GPIO46: weak pull-down. With GPIO0 = 1 it is ignored (normal boot); download mode needs GPIO0 = 0 and GPIO46 = 0, and GPIO0 = 0 with GPIO46 = 1 is not a valid mode. Leave it unconnected or low.
    • GPIO45: weak pull-down; sets the flash voltage (0 = 3.3 V, default, 1 = 1.8 V) unless an eFuse fixes it. Do not pull it high on a module with 3.3 V flash.
    • GPIO3: no internal pull; selects the JTAG source only if the STRAP_JTAG_SEL eFuse is burnt. With default eFuses it is ignored, so floating is fine.
Example circuit: Decoupling, EN RC + RESET, BOOT on GPIO0, USB on pins 13/14. Every other pin carries a no-connect mark; use them for your design.
Decoupling, EN RC + RESET, BOOT on GPIO0, USB on pins 13/14. Every other pin carries a no-connect mark; use them for your design. Open the esp32s3_minimal example from this page in PCB Canvas: “Insert into my schematic”.

Pitfalls#

  • PSRAM variants (N8R8, N16R8 with octal PSRAM) use GPIO35–37 internally: do not use those pins.
  • Antenna keep-out as with every module.
  • Avoid GPIO45/46 as inputs that something might pull during reset.

Sources: Espressif ESP32-S3 Hardware Design Guidelines, schematic checklist (power, CHIP_PU RC, strapping GPIO0/GPIO3/GPIO45/GPIO46 defaults, USB GPIO19/20).

Footprint#

SMD module, 18 × 25.5 mm: ESP32-S3-WROOM-1-N16R8 (C2913202, extended part, 16 MB flash and 8 MB PSRAM). JLCPCB assembly recommended.