ESP32-S3 program does not run correctly with PlatformIO, but works fine with the Arduino IDE

PlatformIO IDE
1

Hello, I’m programming a custom board through USB CDC connected directly to pins 23 and 24 on an ESP32-S3-MINI-1-N8.

After pulling the boot pin low and toggling reset, the COM port appears and I can upload a program using the Arduino IDE. I can then reset the chip and my program prints to the COM port as expected.

When I perform the same steps using my PlatformIO project, the program uploads successfully, but the COM port does not reappear after I reset the chip.

Here are the settings used in the Arduino IDE:

Screenshot 2025-07-22 155012
Screenshot 2025-07-22 155012475×710 12.8 KB

Here is my board configuration:

templog-v1.json:

{
  "build": {
    "arduino":{
      "ldscript": "esp32s3_out.ld",
      "partitions": "default_8MB.csv"
    },
    "core": "esp32",
    "extra_flags": [
      "-DARDUINO_ESP32S3_DEV",
      "-DARDUINO_USB_MODE=1",
      "-DARDUINO_USB_CDC_ON_BOOT=1",
      "-DARDUINO_RUNNING_CORE=1",
      "-DARDUINO_EVENT_RUNNING_CORE=1"
    ],
    "f_cpu": "240000000L",
    "f_flash": "80000000L",
    "flash_mode": "qio",
    "hwids": [
      [
        "0x303A",
        "0x1001"
      ]
    ],
    "mcu": "esp32s3",
    "variant": "esp32s3"
  },
  "connectivity": [
    "bluetooth",
    "wifi"
  ],
  "debug": {
    "default_tool": "esp-builtin",
    "onboard_tools": [
      "esp-builtin"
    ],
    "openocd_target": "esp32s3.cfg"
  },
  "frameworks": [
    "arduino",
    "espidf"
  ],
  "name": "TemplogV1.0 8M Flash",
  "upload": {
    "flash_size": "8MB",
    "maximum_ram_size": 327680,
    "maximum_size": 8388608,
    "wait_for_upload_port": true,
    "require_upload_port": true,
    "speed": 921600
  },
  "url": "https://docs.espressif.com/projects/esp-idf/en/latest/esp32s3/hw-reference/esp32s3/user-guide-devkitc-1.html",
  "vendor": "Espressif"
}

Here is my platformio.ini:

[platformio]
build_cache_dir = buildCache/

[env:templog-esp-s3]
platform = espressif32
board = templog-v1
board_build.arduino.memory_type = dio_opi
framework = arduino
monitor_speed = 115200
monitor_port = COM671
upload_port = COM671
build_flags =
    -DCORE_DEBUG_LEVEL=5
    -Werror=return-type
lib_ldf_mode = deep+
platform_packages =
tool-esptoolpy@1.40801.0

Here is my program:

#include <Arduino.h>

void setup() {

    Serial.begin();
}

void loop() {

    Serial.println("Hello");
    delay(500);
}

What could be missing from my configuration that prevents the serial port from coming back up?

Some minor details:

  • The board has no LEDs or test points so I can’t verify if the program is running at all, or if it’s just a CDC COM port issue
  • When I enter upload mode with the boot/enable sequence and upload with PlatformIO, the COM port does not immediately disappear, and when I open it, I see this bootloader message “ESP-ROM:esp32s3-20210327”. After resetting the board, it does not reappear.

Thank you!

2

You did not specify the platform version.

Which Espressif Arduino version do you use in Arduino IDE and which version do you have installed in PlatformIO?

3

For the Arduino IDE, it works with both 3.2.1 as well as 2.0.17.

For platform IO, I have now specified
platform = espressif32@6.11.0

So I’m not sure which version I was using before, but I get the same results with 6.11.0

4

I think your memory_type is wrong.
Assuming your board has QIO Flash and OPI PASRAM this setting must be
board_build.arduino.memory_type = qio_opi

To get Arduino 3.2.1 and to rule out other sources of possible errors, please use this platformio.ini:

[env:templog-esp-s3]
platform = https://github.com/pioarduino/platform-espressif32/releases/download/54.03.21/platform-espressif32.zip
board = templog-v1
board_build.arduino.memory_type = qio_opi
framework = arduino
monitor_speed = 115200
monitor_port = COM671
upload_port = COM671
build_flags =
    -DCORE_DEBUG_LEVEL=5
5

Manually updating to 3.2.1 fixed the issue!

Thanks! you’re awesome.