AmidalaShield

AmidalaBoard (AmidalaShield)

A custom KiCad PCB shield designed specifically for the Amidala Firmware — a control system for astromech and similar droid builds. This board provides all the I/O the firmware needs in a single, purpose-built package.

Designed by thePunderWoman

The electrical design is written in Stackup KDL, using the pinned Stackup parts library plus board-specific parts. The KiCad PCB is linked to it through AmidalaShield.stackup_sch; sync it with the Stackup KiCad plugin after changing the design. See stackup/README.md.

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Overview

The AmidalaShield is a carrier/breakout board for the ESP32-S3 N16R8 DevKit. It breaks out and conditions the ESP32-S3's peripherals for the specific needs of the Amidala Firmware: wireless XBee communication, multi-channel servo control, RC receiver input, SD card storage, and expansion headers for additional peripherals.

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Requirements

• Microcontroller: ESP32-S3 N16R8 DevKit (16 MB flash, 8 MB PSRAM)
• Wireless modules: XBee3 modules (x2 recommended — one for drive controller, one for dome controller)

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Hardware Features

Wireless Communication

• XBee3 module socket for dual-controller operation (drive + dome)

Servo Control

• 4× PWM servo outputs — 3-pin headers (signal, power, ground)

Serial Ports

• 3× hardware serial ports — UART0 (shared with USB/programming, silkscreen "Serial 0"), UART1 ("Serial 1"), and UART2 ("Serial 2"). None of these are bit-banged/software serial — the ESP32-S3's UART peripherals route through its GPIO matrix onto whichever pins are needed, unlike chips with a single hardware UART. Firmware reassigns the dome drive and drive system's serial link between Serial 1/Serial 2 at runtime — see the Amidala firmware wiki's Serial Ports page.

I/O

• 4× digital I/O pins
• 2× analog input pins
• 1× Aux I2C header — for external I2C devices

RC Control

• PPM input (ppmin) — for analog RC receiver

Storage

• Built-in microSD card reader — used for config.txt at startup (matches Amidala Firmware config system)

Expansion

• Dedicated SPI header — for external SPI peripherals

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Repository Contents

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Getting Started

1. Clone this repo and open AmidalaShield.kicad_pro in KiCad 8+.
2. Review the Stackup design and the GPIO table below for pin assignments before assembling.
3. Use the Gerber files in gerbers/ to order PCBs from your preferred fab.
4. Flash your ESP32-S3 with the Amidala Firmware.
5. Place a config.txt on the microSD card — see the firmware repo for a full annotated example.

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GPIO Table

V1.1 — Updated GPIO assignments for ESP32-S3 WROOM-1 N8R2/N16R2 (Quad flash/PSRAM). Avoid GPIO35–37 on R8 (Octal) variants. GPIO48 reserved for onboard RGB LED.

Pins Intentionally Avoided

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License

This hardware design is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (CC BY-NC-SA 4.0).

You are free to share and adapt this design for non-commercial purposes, as long as you give appropriate credit and distribute any adaptations under the same license.