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As of 2025-09-10

How to Upload Files to ESP32 (Arduino IDE 2.x)

Method for uploading files to the ESP32 mounted on TWELITE SPOT

This guide explains how to upload files (files under the data/ folder) to the ESP32 mounted on TWELITE SPOT.

This section covers advanced topics (how to treat the flash area of the ESP32 mounted on TWELITE SPOT as a file system and upload files like HTML).

If you don’t have requirements such as uploading HTML files to TWELITE SPOT to make it function as a web server (achieved in the spot-server sample) or uploading encryption key files to TWELITE SPOT, you can ignore this section.

This section uses third-party open source software.

We cannot provide detailed usage instructions for third-party software. Also, we assume no responsibility for any damage caused by using third-party software.

The method described in this section uses Arduino IDE 2.x.

Installing the Plugin

Install the Arduino IDE 2.x plugin (earlephilhower/arduino-littlefs-upload) for uploading files to the ESP32 flash area.

Download the Plugin

Download arduino-littlefs-upload-x.x.x.vsix from the following page:

Releases · earlephilhower/arduino-littlefs-upload

Install the Plugin

Place the downloaded arduino-littlefs-upload-x.x.x.vsix in .arduinoIDE/plugins under your user directory.

Windows example: C:\Users\foo\.arduinoIDE\plugins\
macOS/Linux example: ~/.arduinoIDE/plugins/

Host Connection

Connect TWELITE R3 / R2

Connect TWELITE R3 / R2 to the 7P interface (the side marked ESP32).

Connect Power

Supply 5V power to the side USB-C connector.

Make sure to connect TWELITE R3 / R2 to TWELITE SPOT in the same orientation as shown in the figure above. Connecting it in the wrong orientation may damage TWELITE SPOT or TWELITE R3 / R2.

Arduino IDE Operations

Open Sketch

Launch Arduino IDE and open your sketch.

Place Files to Upload

Open the sketch folder from Sketch -> Show Sketch Folder.
Create a data folder at the same level as the sketch file (.ino).
Place the files you want to upload inside the data folder.

The hierarchical structure within the data folder is preserved in the flash area.

Select Serial Port

Select the TWELITE R3 / R2 port from Tools -> Port menu.

The serial port will have names like COM? on Windows, and /dev/tty? on macOS / Linux.

Start ESP32 in Program Mode

Press the ESP32 reset switch EN(RST) and ESP32 boot switch BOOT on TWELITE SPOT, then release them in the order EN(RST) -> BOOT.

By pressing BOOT while resetting, you can put the ESP32 into program mode.

Execute Upload

Press Ctrl+Shift+P (or ⌘+Shift+P on macOS) to open the command palette.
Select Upload LittleFS to Pico/ESP8266/ESP32.

When the upload is complete, Completed upload. will be displayed at the bottom of the screen.

Reset ESP32

After the upload is complete, press and release the ESP32 reset switch EN(RST) on TWELITE SPOT to reset the ESP32.