Connect to Your Comma Device#

A comma four or comma 3X is a normal Linux computer that exposes SSH and a serial console.

SSH#

In order to SSH into your device, you’ll need a GitHub account with SSH keys. See this GitHub article for setting up your account with SSH keys.

Enable SSH in your device’s settings
Enter your GitHub username in the device’s settings
Connect to your device:
- Username: comma
- Port: 22

Example command using the device’s tethered connection:

ssh comma@192.168.43.1

For development work on device, it’s recommended to use SSH agent forwarding.

The public keys are only fetched from your GitHub account once. To update your device’s authorized keys, re-enter your GitHub username.

ssh.comma.ai proxy#

With a comma prime subscription, you can SSH into your comma device from anywhere.

Add the following to your ~/.ssh/config to connect with ssh comma-{dongleid}:

Host comma-*
  Port 22
  User comma
  IdentityFile ~/.ssh/my_github_key
  ProxyCommand ssh %h@ssh.comma.ai -W %h:%p

Host ssh.comma.ai
  Hostname ssh.comma.ai
  Port 22
  IdentityFile ~/.ssh/my_github_key

One-off connection (replace ffffffffffffffff with your dongle ID):

ssh -i ~/.ssh/my_github_key -o ProxyCommand="ssh -i ~/.ssh/my_github_key -W %h:%p -p %p %h@ssh.comma.ai" comma@ffffffffffffffff

ssh.comma.ai host key fingerprint:

Host key fingerprint is SHA256:X22GOmfjGb9J04IA2+egtdaJ7vW9Fbtmpz9/x8/W1X4
+---[RSA 4096]----+
|                 |
|                 |
|        .        |
|         +   o   |
|        S = + +..|
|         + @ = .=|
|        . B @ ++=|
|         o * B XE|
|         .o o OB/|
+----[SHA256]-----+

Serial Console#

On the comma 3X, the serial console is accessible from the main OBD-C port. Connect the comma 3X to your computer with a normal USB-C cable, or use a comma serial for steady 12V power.

The serial console is accessible through the panda using the panda/tests/som_debug.sh script.

Username: comma
Password: comma

Serial console access through the OBD-C port is not available on the comma four. On comma four devices, serial access requires opening the device to access the internal debug connector.

ADB#

Plug your device into constant power, letting it boot up
Enable ADB in your device’s settings
Plug your device into your PC using the USB port
Connect to your device:
- adb shell over USB
- adb connect 192.168.43.1:5555 over WiFi (default ADB port on comma four is 5555)

For more info on ADB, see the Android Debug Bridge (ADB) documentation.