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Joseph Komosa edited this page Mar 20, 2026 · 1 revision

Gain CLI access to the MYND speaker (UART)

This guide explains how to access the MYND speaker’s UART Command-Line Interface (CLI) for diagnostics and factory/test features.

The MYND CLI is not a regular USB serial device: you’ll use a 3.3V FTDI USB‑to‑UART adapter and connect to MYND either:

  • Internally (disassembly; direct UART pins), or
  • Externally via USB‑C (factory firmware only; UART is routed onto USB‑C D+ / D− plus GND)

Example task using the CLI:

Common requirements (both methods)

  • 3.3V USB‑to‑UART adapter (FTDI TTL-232R-3V3 or similar)
  • Serial terminal (PuTTY, screen, minicom, etc.)

Serial settings

  • 115200 baud
  • 8N1 (8 data bits, no parity, 1 stop bit)
  • No flow control

What “success” looks like

  • When you press Enter, you should get a MYND$ prompt.
  • Type help to list available commands.
  • Factory/test commands require test mode to first be activated:
    • AZ enter test mode
    • AX exit test mode

Method 1: UART via USB‑C (no disassembly; factory firmware only)

This method routes UART onto the USB‑C connector’s USB2 D+ / D− lines plus GND and requires a small adapter cable.

Requirements:

  • Factory firmware installed
  • USB‑C breakout/adapter (or a spliced USB‑C cable) that exposes D+, D−, GND

Steps:

  1. Update Firmware:
    Flash the factory firmware via USB-C drag & drop.
    See: Perform a Drag & Drop USB Firmware Update
  2. Build / connect the USB‑C → FTDI cable:
    Follow: How to build the USB‑C → FTDI (UART) cable for MYND logs and CLI
  3. Power On:
    Turn on the MYND speaker.
  4. Enable UART routing to USB‑C:
    • Press and hold PWR + BT (medium press) to enable serial over USB-C.

      Note: On production firmware, this combo instead announces firmware versions.

  5. Connect FTDI to computer:
    Install drivers and identify the serial port.
  6. Open serial terminal and connect:
    Open the serial port and press Enter to reach the MYND$ prompt.
  7. (Optional) Restore production firmware:
    When done, update back to production firmware.

Method 2: Via Internal UART Debug Pins (requires disassembly)

Requirements:

  • Disassembly of the MYND speaker

Steps:

  1. (Optional) Update firmware:
    Use USB‑C drag & drop to flash the firmware you need (production or factory).
  2. Disassemble Speaker:
    Open the MYND case and remove the speaker to access the PCB.
  3. Connect FTDI Device:
    • Plug FTDI into your computer and install drivers.
    • Identify the assigned serial port (tty on Linux, COM on Windows).
  4. Wire Connections:
    • FTDI TX → MYND RX
    • FTDI RX → MYND TX
    • FTDI GND → MYND GND
    • See mynd-hardware for pinout.
  5. Enable Power:
    Short pins 4 and 5 of the amp connector (P1S CJL008DH250197) or the unit won't power on.
    See schematic (PDF)
  6. Power On:
    Turn on the MYND speaker.
  7. Open serial terminal and connect:
    Open the serial port and press Enter to reach the MYND$ prompt.
  8. (Optional) Restore production firmware:
    If you used factory firmware for tests, restore production firmware when done.

Troubleshooting

  • No prompt / nothing prints
    • verify you’re on factory firmware (USB‑C method)
    • verify you pressed PWR + BT to route UART to USB‑C (USB‑C method)
    • verify FTDI is 3.3V
    • verify common GND
    • for USB‑C method: swap the D+/D− ↔ TX/RX mapping in your cable
  • Garbled output
    • confirm 115200 baud and no flow control
  • MYND does not power on
    • Mynd cannot power on when it is open (speaker frame has been removed)
    • If you wish to power on the MYND while it is open (access to flash and uart debug pins for development and/or testing), you must first short pins 4 and 5 of the P1S amp baffle connector component

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