Flash the ESP32-CAM (Legacy)

This guide walks through flashing the SmartPot firmware onto an ESP32-CAM module for the submerged vision unit.

ESP32-CAM Reference

For detailed ESP32-CAM hardware documentation — GPIO pinout, architecture, and QEMU-based testing — see the ESP32-CAM project docs. That project also provides a USB daughter-board design that eliminates the manual FTDI wiring described below.

Prerequisites

• ESP32-CAM (Ai-Thinker) module
• USB-to-serial adapter (FTDI FT232RL or CP2102)
• Jumper wires
• USB cable
• Computer with Arduino IDE or PlatformIO installed

Wiring

The ESP32-CAM doesn’t have a built-in USB port. Connect a USB-to-serial adapter:

USB-Serial	ESP32-CAM
3V3	3V3
GND	GND
TX	U0R (GPIO3)
RX	U0T (GPIO1)

For flashing mode: Connect IO0 to GND before powering on. This puts the ESP32 into bootloader mode. Remove the IO0-to-GND connection after flashing and press RESET to boot normally.

flowchart TD
    subgraph ser["USB-Serial Adapter"]
        S_3V3["3V3"]
        S_GND["GND"]
        S_TX["TX"]
        S_RX["RX"]
    end

    subgraph cam["ESP32-CAM (Ai-Thinker)"]
        C_3V3["3V3"]
        C_GND["GND"]
        C_RX["U0R (GPIO3)"]
        C_TX["U0T (GPIO1)"]
        C_IO0["IO0"]
    end

    S_3V3 --- C_3V3
    S_GND --- C_GND
    S_TX --- C_RX
    S_RX --- C_TX
    C_IO0 -. "GND during flash" .-> C_GND

    style ser fill:#e6f3f0,stroke:#2d7d6f
    style cam fill:#f0f4f8,stroke:#4a6785

Caution

Use 3V3, not 5V, when powering the ESP32-CAM from the serial adapter during flashing. Some USB-serial adapters provide 3.3V on their 3V3 pin but 5V tolerance varies by ESP32-CAM board revision. If your adapter only provides 5V, use an external 3.3V regulator or power the ESP32-CAM from a separate 5V source on its 5V pin.

Install ESP32 Board Support

Arduino IDE

1. Open File → Preferences
2. Add to Additional Board Manager URLs:

   https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

3. Open Tools → Board → Board Manager
4. Search for “esp32” and install esp32 by Espressif Systems
5. Select Tools → Board → AI Thinker ESP32-CAM

PlatformIO

; platformio.ini
[env:esp32cam]
platform = espressif32
board = esp32cam
framework = arduino
monitor_speed = 115200
upload_speed = 921600

Flash the Firmware

1. Connect GPIO0 to GND (flash mode jumper)
2. Connect USB-serial adapter to computer
3. Power on the ESP32-CAM
4. Select the correct COM/serial port
5. Click Upload (Arduino IDE) or run pio run -t upload (PlatformIO)
6. Wait for upload to complete (progress bar shows percentage)
7. Remove the GPIO0-to-GND jumper
8. Press the RESET button on the ESP32-CAM

Caution

If upload fails with “Failed to connect to ESP32”:

1. Check that GPIO0 is connected to GND
2. Try pressing RESET while the IDE is trying to connect
3. Reduce upload speed to 115200
4. Try a different USB cable (data cables, not charge-only)

Verify

Open the serial monitor at 115200 baud. You should see:

SmartPot Submerged Unit v0.1
Camera initialized: OV2640
TFLite model loaded: species_v1.tflite
Servo initialized: door UNLOCKED
Waiting for tether connection...

Next Steps

• Load the species classification model (see Train the Species Model)
• Connect to the smart buoy via tether cable
• Configure keeper thresholds for your target species