seeed-projects/seeed-jetson-developtool/system-log-j30-j40

Get System Log of reComputer J30/J40

Execution model

Run one phase at a time. After each phase, verify the expected result before continuing.

• If a phase succeeds → print [OK] and move to the next phase.
• If a phase fails → print [STOP], consult the failure decision tree, and ask the user before retrying.

Phase 1 — Verify prerequisites

Required hardware:

• reComputer J4012, J4011, J3010, or J3011
• USB to Serial (TTL) module (e.g., CH340G)
• Host PC with a serial port debugging tool (PuTTY, XShell, or MobaXterm)

Install a serial debugging tool on the host PC if not already available.

Phase 2 — Hardware connection

1. Connect the J15 interface pins on the reComputer to the USB2TTL module:

• TX → RX
• RX → TX
• GND → GND

1. Connect the USB2TTL module to the host PC via USB.

Expected: USB2TTL module recognized by the host PC.

Phase 3 — Identify the serial port

On the host PC, find the USB2TTL device identifier:

# Linux
ls /dev/ttyUSB* /dev/ttyACM*
dmesg | tail -20

On Windows: Open Device Manager and look under "Ports (COM & LPT)" for the COM port number.

Expected: Serial device identified (e.g., /dev/ttyUSB0 on Linux or COM3 on Windows).

Phase 4 — Configure serial debugging tool

Open your serial debugging tool and configure:

• Serial port: the port identified in Phase 3
• Baud rate: 115200
• Data bits: 8
• Stop bits: 1
• Parity: None
• Flow control: None

Click Connect / Open to start the serial session.

Expected: Serial session opens without errors.

Phase 5 — Capture boot logs

Power on (or reboot) the Jetson device. The boot logs should appear in the serial debugging tool window.

# If you need to reboot the Jetson remotely
sudo reboot

Expected: System boot logs stream in the serial terminal, showing kernel messages and boot sequence.

Failure decision tree

Reference files

• references/source.body.md — Full original wiki content (reference only)