Quick Start Guide
 | The Rubik Pi 3 documentation from RidgeRun is presently being developed. |
To start a RUBIK Pi 3 quickly, use a USB-C PD 3.0 power supply rated for 12 V / 3 A, connect HDMI plus keyboard and mouse for local setup, and optionally connect the Micro USB debug port for UART access.
On current Ubuntu images, the default login is typically `ubuntu` / `ubuntu` before the first password reset, and the board can then be networked with `nmcli`, accessed over SSH, or reflashed through EDL mode using Qualcomm tooling.
This page is part of Rubik Pi 3. It focuses on first boot, Ubuntu bring-up, networking, SSH, camera smoke tests, and recovery / flashing.
What's in the RUBIK Pi 3 developer kit box
Below is a photo of the box that you receive when purchasing the Rubik Pi 3.
Inside the box comes the developer kit and a quick start guide shown in the photo below.
What you need
For a smooth first session, prepare the following:
| Item | Why it matters |
|---|---|
| RUBIK Pi 3 board | The target platform |
| USB-C PD 3.0 power adapter, 12 V / 3 A | Required for reliable power negotiation and boot |
| HDMI display | Simplest way to confirm graphical boot |
| USB keyboard and mouse | Useful in SBC / local desktop mode |
| Micro USB cable | Debug UART access |
| USB-C data cable | Useful for flashing and recovery workflows |
| Ethernet or Wi-Fi credentials | Required for updates, SSH, and package installs |
| Optional CSI camera | Lets you validate the camera pipeline immediately |
Users can verify the compatibility of components against the official Peripheral Compatibility List.
First boot checklist
1. Connect the essentials
Connect the following in this order:
- HDMI display
- Keyboard and mouse if you want local interaction
- Optional Ethernet
- Optional Micro USB cable for debug UART
- USB-C PD power supply
2. Power-on behavior
The board powers up automatically when the power adapter is connected. In normal operation, the LED next to the PWR and EDL buttons will turn on Green. Then around the time the board has completed the boot, the LED near the DEBUG port will blink Green.
3. Default login
Ubuntu
For current Canonical Ubuntu workflows, the vendor setup guide shows the initial account as:
Username: ubuntu Password: ubuntu
Right after the first login, you'll be prompted to change the password.
After that you can check the Ubuntu version installed with:
lsb_release -a
This is an example of the terminal output:
No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 24.04.3 LTS Release: 24.04 Codename: noble
Or you can also use <coe>cat /etc/os-release
PRETTY_NAME="Ubuntu 24.04.3 LTS" NAME="Ubuntu" VERSION_ID="24.04" VERSION="24.04.3 LTS (Noble Numbat)" VERSION_CODENAME=noble ID=ubuntu ID_LIKE=debian HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" UBUNTU_CODENAME=noble LOGO=ubuntu-logo
Qualcomm Linux
The default credentials are:
Username: root Password: rubikpi
Use cat /etc/os-release to check the OS version. This is an example output:
ID=qcom-wayland NAME="Qualcomm Linux" VERSION="1.5-ver.1.1" VERSION_ID=1.5-ver.1.1 PRETTY_NAME="Qualcomm Linux 1.5-ver.1.1" CPE_NAME="cpe:/o:openembedded:qcom-wayland:1.5-ver.1.1"
Access methods
HDMI + local shell
This is the easiest option for first bring-up. Connect HDMI, power the board, and verify that the system reaches the Ubuntu desktop or shell environment expected by your chosen image. This method is ideal for validating display, keyboard, mouse, and basic user login.
UART debug over Micro USB
UART access is the most reliable method when HDMI output is unavailable, networking is not configured yet, or you need to observe low-level boot behavior.
First, you need to identify the device node to open the serial console. Run the following command in the terminal:
sudo dmesg -w
Then connect a Micro USB cable between the RUBIK Pi debug port and the computer. Look at the latest lines in the terminal, it may look similar to the following:
[2599255.538749] usb 3-4: new full-speed USB device number 56 using xhci_hcd [2599255.663849] usb 3-4: New USB device found, idVendor=1a86, idProduct=55d3, bcdDevice= 4.45 [2599255.663861] usb 3-4: New USB device strings: Mfr=0, Product=2, SerialNumber=3 [2599255.663866] usb 3-4: Product: USB Single Serial [2599255.663870] usb 3-4: SerialNumber: 5A9B111197 [2599255.666938] cdc_acm 3-4:1.0: ttyACM0: USB ACM device
In this example, the device we need is ttyACM0. Now we can open a serial console with screen:
sudo screen /dev/ttyACM0 115200
Remember to adjust the command with the corresponding USB ACM device in your system.
Network setup
This section answers How do I get RUBIK Pi 3 on the network?
Wi-Fi
Log into the RUBIK Pi with UART or using the Display and keyboard, then connect to Wi-Fi with nmcli, verify the IP address with ip addr, and then switch to SSH for normal development.
Typical workflow:
sudo nmcli dev wifi connect <WiFi-SSID> password <WiFi-password> sudo nmcli -p device ip addr
Ethernet
For lab use and continuous development, Ethernet is usually the simplest option. Connect the RJ45 cable, wait for link negotiation, and run:
ip addr
Record the assigned address so the board can be reached through SSH and automation tools.
SSH setup
Once the board is on the network, connect from the host system with:
ssh ubuntu@<board-ip-address>
Example:
ssh ubuntu@192.168.0.222
SSH is usually the preferred mode for package installation, file transfer, source builds, remote scripting, and CI-driven validation.
Flashing and recovery
When to reflash
Reflash the board when:
- you need to switch operating systems,
- you need to test a custom image,
- the current image is damaged,
- you need a known-clean test baseline,
- you are validating a regression across image versions,
- or the board is locked in a recovery or fastboot state.
EDL mode
RUBIK Pi 3 supports EDL (Emergency Download) mode for low-level image flashing. Current vendor documentation shows two broad paths:
- hardware-button entry into EDL, and
- software-triggered entry from Ubuntu using `sudo reboot edl`.
When to use software-triggered EDL?
Use this method when the board is able to boot into the Operating System successfully and you can login. If the image is damaged, then you will need to enter EDL via hardware-button.
How to enter EDL via hardware-button
While holding the EDL button, connect power, USB-C data port (to the computer) and then release the EDL button (see picture below for reference).
How to verify if the board is really in EDL mode?
In the output of the lsusb command on the computer you should see something similar to this:
Bus 003 Device 057: ID 05c6:9008 Qualcomm, Inc. Gobi Wireless Modem (QDL mode)
Host-side flashing tools
The standard procedure to flash Ubuntu and Qualcomm Linux is to use Qualcomm Launcher. Refer to the official Thundercomm guide for a step-by-step procedure.
First camera smoke test
A quick way to prove that the board, camera connector, and software stack are all alive is to capture images with `qtiqmmfsrc`.
First prepare the environment with the following commands:
export XDG_RUNTIME_DIR=/dev/socket/weston export WAYLAND_DISPLAY=wayland-1 echo multiCameraLogicalXMLFile=kodiak_dc.xml > /var/cache/camera/camxoverridesettings.txt echo enableNCSService=FALSE >> /var/cache/camera/camxoverridesettings.txt systemctl restart cam-server.service
The following are examples of the simplest pipelines:
# CAM1 gst-launch-1.0 qtiqmmfsrc camera=0 ! waylandsink # CAM2 gst-launch-1.0 qtiqmmfsrc camera=1 ! waylandsink
For deeper multimedia workflows and camera troubleshooting, continue to Rubik Pi 3/GStreamer.
Common first-day issues
Board does not boot
Start with power check. The board requires proper USB-C PD negotiation with a 12 V / 3 A source. A weak adapter or a laptop port is not a valid replacement for a verified power supply.
No HDMI output
Connect UART to verify if the board is booting successfully. If the boot is successful and you can login, then review the display connection and compatibility, as well as the image version to confirm there is a display server installed. If the boot is unsuccessful, you can extract the error information from the boot log for debugging.
No serial prompt
Reconnect the Micro USB cable, confirm the host serial device node, and reopen the terminal at 115200 baud.
Cannot find the board on the network
Use UART access to inspect nmcli and ip addr, and verify whether you are on Wi-Fi or Ethernet. Before connecting through ssh, verify that a ping <RUBIK ip address> from your computer works, to discard incorrect ip address and firewall problems.
Camera not detected
Ensure that the camera is connected correctly; never hotplug a MIPI camera, turn-off the RUBIK Pi and then fix the connection. If the problem persist, head to Rubik_Pi_3/GStreamer troubleshooting section.
Recommended first-hour workflow
A productive first-hour session on a new board usually looks like this:
1. Power board with verified 12 V / 3 A PD supply 2. Log in locally or through UART 3. Confirm OS version (Ubuntu or Qualcomm Linux) 4. Bring up Ethernet or Wi-Fi 5. Enable SSH workflow 6. Run one camera smoke test
Frequently asked questions
- What power supply does RUBIK Pi 3 need?
- Use a USB-C PD 3.0 power adapter rated for 12 V / 3 A. Do not rely on a laptop USB port to power the board.
- What is the default Ubuntu login on a fresh image?
- Official Ubuntu images have username `ubuntu` and password `ubuntu` before the mandatory password reset. Official Qualcomm Linux images have username `root` password `rubikpi` before the mandatory password reset.
- How do I SSH into RUBIK Pi 3?
- Bring the board onto Wi-Fi or Ethernet, find the IP address with `ip addr`, and connect with `ssh ubuntu@<ip>`.
- How do I reflash the board?
- Use Qualcomm Launcher and EDL mode. Qualcomm Launcher allows to flash official Ubuntu and Qualcomm Linux images as well as custom images
- What is the fastest proof that the camera stack works?
- Run a simple `qtiqmmfsrc` capture command.
Related pages