ESP32-S3-BOX-3 Configuration Guide

This document describes the hardware configuration for using the Espressif ESP32-S3-BOX-3 development board with the nematostella time-series imaging system.

Hardware Overview

The ESP32-S3-BOX-3 is an AIoT development platform featuring: - ESP32-S3-WROOM-1 module (Wi-Fi + Bluetooth 5 LE) - 16 MB Flash, 16 MB PSRAM - 2.4" 320x240 SPI touchscreen display - Integrated sensors (microphones, gyroscope, accelerometer) - USB Type-C connectivity

The ESP32-S3-BOX-3-DOCK accessory provides: - Two Pmod™ compatible headers with 16 programmable GPIOs - USB Type-A host port - Additional USB Type-C power input

GPIO Pinout

Pmod Header Configuration

The ESP32-S3-BOX-3-DOCK exposes two Pmod headers with the following pinout:

Left Pmod Header (PIN 1)

Row 1: G10  | G14  | G11  | G43/U0TXD | GND | 3V3
Row 2: G13  | G9   | G12  | G44/U0RXD | GND | 3V3

Right Pmod Header (PIN 1)

Row 1: G21  | G19/USB- | G38  | G41  | GND | 3V3
Row 2: G42  | G20/USB+ | G39  | G40  | GND | 3V3

Available GPIO Pins

Total of 16 programmable GPIOs available: - G9, G10, G11, G12, G13, G14 - G19, G20, G21 - G38, G39, G40, G41, G42, G43, G44

Note: G19/G20 are shared with USB, and G43/G44 are shared with UART. Avoid using these unless you don't need USB host functionality or serial debugging.

Internal Peripheral Usage (DO NOT USE)

The following GPIOs are reserved by internal peripherals on the ESP32-S3-BOX-3 main unit:

Display Controller: - GPIO4 (DC), GPIO5 (CS), GPIO6 (SDA), GPIO7 (SCK) - GPIO48 (RST), GPIO47 (CTRL)

Audio System: - GPIO2 (I²S_MCLK), GPIO17 (I²S_SCLK), GPIO45 (I²S_LRCK) - GPIO15 (codec data), GPIO46 (PA control)

I²C Bus (Sensors/Codec): - GPIO18 (I²C_SCL), GPIO8 (I²C_SDA)

Other: - GPIO1 (mute status)

Pin Assignment for LED Control & DHT22

Recommended GPIO Pin Mapping

For compatibility with the nematostella imaging system, we need 3 GPIO pins:

Function	ESP32 (Original)	ESP32-S3-BOX-3 (New)	Notes
IR LED Control	GPIO 4	GPIO 10	PWM output for IR MOSFET gate
White LED Control	GPIO 15	GPIO 11	PWM output for White MOSFET gate
DHT22 Data	GPIO 14	GPIO 12	Digital I/O with pull-up

Rationale: - GPIO 10, 11, 12 are sequential, easy to remember, and safe to use - All support PWM (LEDC peripheral on ESP32-S3) - GPIO 12 supports digital I/O with pull-up for DHT22 - None conflict with internal peripherals

Alternative Pin Options

If GPIO 10/11/12 are unavailable, use these alternatives:

Option 2: - IR LED: GPIO 38 - White LED: GPIO 39 - DHT22: GPIO 40

Option 3: - IR LED: GPIO 13 - White LED: GPIO 14 - DHT22: GPIO 9

Wiring Diagram

MOSFET Connection (Updated for ESP32-S3-BOX-3)

IR LED Circuit:

                    ┌─────────────┐
ESP32-S3 GPIO 10 ──►│ Gate        │
(3.3V PWM)          │  IRLZ34N    │
                    │  MOSFET     │
                    │             │
12V PSU (+) ────────┤ Drain       │
                    │             │
                    │ Source      ├─────► IR LED Strip (+)
                    └─────────────┘
                                        IR LED Strip (-) ──► GND

White LED Circuit:

                    ┌─────────────┐
ESP32-S3 GPIO 11 ──►│ Gate        │
(3.3V PWM)          │  IRLZ34N    │
                    │  MOSFET     │
                    │             │
24V PSU (+) ────────┤ Drain       │
                    │             │
                    │ Source      ├─────► White LED Strip (+)
                    └─────────────┘
                                        White LED Strip (-) ──► GND

DHT22 Sensor Connection

DHT22 Sensor Board:
Pin 1 (VCC)  → ESP32-S3-BOX-3 DOCK 3V3 (Pmod header)
Pin 2 (Data) → ESP32-S3-BOX-3 GPIO 12
Pin 3 (GND)  → ESP32-S3-BOX-3 GND (Pmod header)

Important Notes: - Use 3V3 and GND from the Pmod headers, not from internal ESP32-S3-BOX-3 pins - DHT22 sensor board should have integrated pull-up resistor - Keep wires short (<30cm) for reliable communication

Complete System Wiring

┌──────────────┐     ┌──────────────┐     ┌──────────────┐
│   USB-C      │     │   12V PSU    │     │   24V PSU    │
│ (ESP32-S3    │     │  (IR LED)    │     │ (White LED)  │
│   BOX-3)     │     │              │     │              │
└──────┬───────┘     └──────┬───────┘     └──────┬───────┘
       │                    │                    │
       │ USB-C              │ 12V+               │ 24V+
       │                    │                    │
       ▼                    ▼                    ▼
   ┌────────────┐      ┌─────────┐         ┌─────────┐
   │ ESP32-S3-  │      │ WAGO #1 │         │ WAGO #2 │
   │ BOX-3-DOCK │      │(IR 12V+)│         │(W 24V+) │
   │            │      └────┬────┘         └────┬────┘
   │ GPIO 10────┼──────┐    │                   │
   │ GPIO 11────┼────┐ │    │                   │
   │ GPIO 12◄───┼─┐  │ │    │                   │
   │  3.3V──┬───┼─┼──┼─┘    │                   │
   │  GND─┬─┼───┼─┼──┘      │                   │
   │  GND─┼─┼───┼─┘         │                   │
   └──┬───┼─┼───┘           │                   │
      │   │ └──DHT22        │                   │
      │   │     VCC         │                   │
      │   │     Data        │                   │
      │   │     GND         └──►IR LED(+)      └──►White LED(+)
      │   │                      12V                24V
      │   │
      │   │            IR MOSFET         White MOSFET
      │   │            Gate◄─GPIO10      Gate◄─GPIO11
      │   │            Drain◄─12V PSU(+) Drain◄─24V PSU(+)
      │   │            Source─┐          Source─┐
      │   │                   │                 │
      ▼   ▼                   ▼                 ▼
   ┌──────────────────────────────────────────────────────┐
   │           WAGO #3 (Common Ground Hub)                │
   │  [1] 12V PSU GND(-)  [2] 24V PSU GND(-)  [3] ESP32-S3 GND│
   │                                                       │
   │  Additional wires connected:                         │
   │  - IR MOSFET Source                                  │
   │  - White MOSFET Source                               │
   │  - IR LED Cathode (-) 12V                            │
   │  - White LED Cathode (-) 24V                         │
   └──────────────────────────────────────────────────────┘

Key Points: - Power Sources: USB-C (ESP32-S3-BOX-3), 12V PSU (IR LED), 24V PSU (White LED) - DHT22 powered from Pmod header 3V3, not internal ESP32-S3-BOX-3 - WAGO #1: 12V+ distribution - [1]=12V PSU(+), [2]=IR LED(+) - WAGO #2: 24V+ distribution - [1]=24V PSU(+), [2]=White LED(+) - WAGO #3: Common ground hub for all power sources - GPIO 10 → IR MOSFET Gate (direct wire from Pmod header) - GPIO 11 → White MOSFET Gate (direct wire from Pmod header)

Firmware Configuration

Required Changes in ESP32 Firmware

The ESP32 firmware must be updated to use the new GPIO pin assignments:

File: ESP32_firmware/src/config.h (or equivalent)

// Original ESP32 pin assignments
// #define IR_LED_PIN 4
// #define WHITE_LED_PIN 15
// #define DHT22_PIN 14

// ESP32-S3-BOX-3 pin assignments
#define IR_LED_PIN 10      // GPIO 10 via Pmod header
#define WHITE_LED_PIN 11   // GPIO 11 via Pmod header
#define DHT22_PIN 12       // GPIO 12 via Pmod header

PWM Configuration:

// PWM settings (unchanged from original)
#define PWM_FREQUENCY 15000  // 15 kHz
#define PWM_RESOLUTION 8     // 8-bit (0-255)
#define PWM_CHANNEL_IR 0
#define PWM_CHANNEL_WHITE 1

DHT22 Configuration:

// DHT22 sensor (unchanged from original)
#define DHTTYPE DHT22
DHT dht(DHT22_PIN, DHTTYPE);

Firmware Upload

Using Arduino IDE or PlatformIO:

1. Select Board: ESP32-S3-Box (or ESP32S3 Dev Module)
2. Configure Partition Scheme: Default 4MB with spiffs
3. USB CDC on Boot: Enabled (for Serial over USB)
4. Upload Mode: UART0 (via USB-C)

Upload Process: 1. Connect ESP32-S3-BOX-3 to computer via USB-C cable 2. Hold BOOT button while pressing RESET button (if needed) 3. Upload firmware from Arduino IDE or PlatformIO 4. Monitor serial output at 115200 baud

Signal Specifications

PWM Signals (GPIO 10, 11): - GPIO 10: IR LED MOSFET Gate - GPIO 11: White LED MOSFET Gate - Logic Level: 3.3V - Frequency: 15 kHz (set in firmware) - Duty Cycle: 0-100% (controlled by plugin) - Rise/Fall Time: <1µs

DHT22 Communication (GPIO 12): - Protocol: Single-wire digital (proprietary) - Pull-up: 10kΩ to 3.3V (integrated on DHT22 board) - Sampling Rate: ~0.5 Hz (one reading per 2 seconds max) - Data Format: 40-bit (16-bit humidity, 16-bit temp, 8-bit checksum)

Serial Communication: - Protocol: UART over USB-C - Baud Rate: 115200 - Data Format: 8N1 (8 data bits, no parity, 1 stop bit)

Display Capabilities (Optional Future Enhancement)

The ESP32-S3-BOX-3 includes a 2.4" touchscreen display that could be used for:

Potential Features:

1. Local Status Display
2. Current LED power levels
3. Temperature and humidity readings
4. Recording status (idle/recording)

5. Connection status (USB/network)

6. Touch Control Interface

7. Manual LED power adjustment
8. Test LED on/off
9. View sensor readings

10. Emergency stop button

11. Data Visualization

12. Real-time temperature/humidity graphs
13. LED duty cycle indicators
14. Recording progress bar

Note: Display functionality is optional and not required for basic operation. The system works identically to the standard ESP32 setup without using the display.

Migration Checklist

• Obtain ESP32-S3-BOX-3 and ESP32-S3-BOX-3-DOCK
• Update firmware pin definitions (GPIO 10, 11, 12)
• Test PWM output on GPIO 10 and 11 with oscilloscope
• Verify DHT22 communication on GPIO 12
• Connect MOSFETs to Pmod header GPIOs
• Wire power distribution (WAGO connectors)
• Test LED control and sensor readings
• Validate full system integration
• (Optional) Implement local display features

Comparison: ESP32 vs ESP32-S3-BOX-3

Feature	ESP32 DevKit	ESP32-S3-BOX-3
Microcontroller	ESP32	ESP32-S3
Flash	4 MB	16 MB
PSRAM	0 MB (usually)	16 MB
Display	None	2.4" 320x240 touchscreen
GPIO Access	Direct pins	Via Pmod headers (DOCK)
Pin Mapping	GPIO 4, 15, 14	GPIO 10, 11, 12
USB	Micro-USB (UART)	USB-C (native USB)
Enclosure	Open dev board	Enclosed with stand
Additional Features	None	Sensors, speaker, microphones

Troubleshooting

LEDs not responding: - Verify GPIO 10/11 are correctly wired to MOSFET gates - Check PWM signal with oscilloscope (0-3.3V square wave at 15kHz) - Ensure firmware is compiled for ESP32-S3 target

DHT22 returns 0.0 values: - Verify 3.3V and GND from Pmod header (not internal ESP32-S3-BOX-3) - Check GPIO 12 connection - Ensure DHT22 board has integrated pull-up resistor

Cannot upload firmware: - Select correct board: ESP32-S3-Box or ESP32S3 Dev Module - Enable "USB CDC on Boot" in board settings - Try holding BOOT button while clicking Upload

Display interferes with operation: - Display uses GPIO 4-7, 47-48 internally - do not use these pins - If display shows garbage, it won't affect LED/sensor operation - Display can be safely ignored if not using it

References

• ESP32-S3-BOX-3 Official Page
• ESP32-S3-BOX GitHub Repository
• ESP32-S3 Datasheet
• ESP-IDF GPIO Documentation

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Last Updated: 2025-12-12