Skip to content
Buy Spikeling units

Flash firmware

This page explains how to (re)flash Spikeling firmware onto the microcontroller. The recommended workflow uses the Arduino IDE and follows the same setup steps described in the Spikeling instruction manual (ESP32 add-on install, board selection, required libraries).

You typically only need to flash firmware when:

  • you are setting up a new device for the first time
  • you want to update to a newer firmware release
  • the device is behaving unexpectedly and you want a clean re-flash
  • you are developing/modifying the Arduino code

Close anything that uses the serial port

Before flashing, close the Spikeling GUI, Arduino Serial Monitor, and any serial terminal (PuTTY, CoolTerm, screen, minicom, etc.). Only one program can use the port at a time.

Board families and USB differences

  • Spikeling v2.x (e.g., v2.5): ESP32 (WROOM-32), mini-USB, USB-to-UART bridge (CP210x) → CP210x driver is typically required.
  • Spikeling v3.x (e.g., v3.0): ESP32-S3 (WROOM-1), USB-C, native USB (USB CDC) → driver typically not required.

The driver and Arduino setup below is essential for v2.x and still applies to v3.x (same ESP32 Arduino core), but the board selection differs.

Step 1 — Install CP210x driver (v2.x only)

Spikeling v2.x uses a CP210x USB-to-UART bridge. Install the Silicon Labs CP210x driver so the board appears as a serial/COM port.

Links : 

CP210x driver page:
https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers

Downloads tab:
https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers?tab=downloads

After installing the driver: - unplug/replug the board - confirm a COM/serial port appears (see Quickstart → Hardware setup)

Step 2 — Install Arduino IDE

Download and install the Arduino IDE.

Link: 

https://www.arduino.cc/en/software

Step 3 — Install the ESP32 add-on (Espressif Arduino core)

In Arduino IDE:

  1. Go to File → Preferences

Arduino Preferences

  1. In Additional Board Manager URLs, add:

Additional Board Manager URLs

  1. Click OK

  2. Open Tools → Board → Boards Manager…

  3. Search for ESP32

  4. Install “ESP32 by Espressif Systems”

install ESP32 by Espressif Systems

Step 4 — Select the correct board target (FQBN)

For Spikeling v2.x (ESP32 WROOM-32)

Select:

  • Tools → Board → esp32 → ESP32 Dev Module Select ESP32 Dev Module

For Spikeling v3.x (ESP32-S3 WROOM-1)

Select an ESP32-S3 target, typically:

  • Tools → Board → esp32 → ESP32S3 Dev Module Select ESP32 Dev Module

(Exact naming can vary slightly by Arduino-ESP32 core version; the key is selecting an ESP32-S3 board definition.)

Step 5 — Install required Arduino libraries

Before compiling the Spikeling firmware, install these libraries:

  • SerialCommand: SerialCommand Library by Shyd (based on Steven Cogswell) https://github.com/shyd/Arduino-SerialCommand

  • MCP_ADC: Microchip SPI ADC Library by Rob Tillaart https://github.com/RobTillaart/MCP_ADC

  • MCP_DAC: Microchip SPI DAC Library by Rob Tillaart https://github.com/RobTillaart/MCP_DAC

  • Gaussian: Gaussian Library by Ivan Seidel https://github.com/ivanseidel/Gaussian

  • WebSocketsServer: Websockets for Arduino(Server + Client) by Markus Sattler https://github.com/Links2004/arduinoWebSockets

  • ArduinoJson: A simple and efficient JSON library for embedded C++ by Benoit Blanchon https://arduinojson.org/?utm_source=meta&utm_medium=library.properties

Install via:

  • Sketch → Include Library → Manage Libraries
  • Search by name and click Install

Manual install note (Arduino-SerialCommand)

You could also manually place the Arduino library folder from the repository into your Arduino libraries directory (especially on Windows).

Windows example path from the manual:

  • C:/Users/<you>/Documents/Arduino/libraries

Repository location: 

https://github.com/OpenSourceNeuro/Spikeling-V2/tree/main/Arduino%20Code/Librairies

Step 6 — Open the firmware sketch

  1. Locate the Spikeling firmware .ino in the repository’s Arduino code folder.
  2. Open the .ino in Arduino IDE.
  3. Keep accompanying .h/.cpp files in the same folder (do not separate them).

Step 7 — Select the port and upload

  1. Plug in the board.

  2. Select the serial port:

  3. Tools → Port → (select the port that appears when you plug the device in)

  4. Click Upload.

Arduino IDE will compile the code and flash it to the board.

If upload fails: bootloader (download) mode

If the upload fails (common symptoms: “Timed out waiting for packet header”, “Failed to connect”), force the ESP32 into download mode.

Typical sequence on many ESP32/ESP32-S3 boards: 1. Hold BOOT 2. Tap RESET/EN 3. Release BOOT when the upload starts

If your Spikeling PCB does not expose BOOT/RESET buttons, consult your board silkscreen or the project’s instruction manual for the exact procedure.

Verify firmware after flashing

After a successful upload:

  1. Unplug/replug the board.
  2. Launch the Spikeling GUI.
  3. Select the correct port and connect.
  4. Confirm you get live traces and the device responds to controls.

If the GUI connects but behavior is incorrect: - confirm you flashed the firmware variant that matches your board family (v2.x vs v3.x) - reflash after a clean rebuild (Arduino IDE compile + upload)