Comma 3, 3X, and 4

The comma 3, 3X, and 4 are the computing and camera units that NAP runs on. They sit on your windshield, see the road ahead, monitor the driver, and communicate with the car through the adapter plugged into the OBD2 port. All NAP features — lane keeping, driver monitoring, forward collision warning, the settings panel — run on this device.

Which device to use

NAP runs on the comma 3, comma 3X, and comma 4. The 3X has improved optics and a wider field of view over the 3, and all three run the same software. comma 3 support is brought by Magzu — see the pre-AP page on Magzu's wiki.

If you're buying a device today, the picture is a little different — comma no longer sells the 3X:

• konik ($729, konik.ai) — a comma 3X-compatible device. A lot of community members run one and are happy with it, and for EU buyers it avoids the VAT and import charges that come with ordering from comma.
• comma 4 ($950, comma.ai shop) — comma's current device, supported by NAP.
• Used comma 3/3X — fully supported if you can find one secondhand.

Mounting

The device mounts to the inside of the windshield using a 3M adhesive bracket. The goal is to position it centered left-to-right and level with the ground, so the road-facing camera has an accurate view of the lane ahead.

Placement tips:

• Clean the windshield surface with isopropyl alcohol before attaching the mount. Any oil or residue will weaken the bond.
• Roll the mount onto the glass one edge at a time to avoid trapping air under the adhesive.
• Leave the mount to cure for 24–48 hours before attaching the device. Keep it out of direct sun during this time; taping a strip of paper to the outside of the glass over the mount location provides shade if needed.
• Cold weather weakens the adhesive bond during application — if it's below freezing, run the defroster for a few minutes to warm the glass first.
• The camera on the left side of the device is the driver-monitoring camera. Position the device so it has a clear view of the driver's face.

Centering the device:

Use masking tape to mark the horizontal midpoint of the windshield at a few heights, then run a vertical strip of tape down the center. Align the mount's centerline to this before pressing.

Cable routing for pre-AP Model S

The comma 3/3X connects to the car via a USB4/Thunderbolt 3 cable. On pre-AP Model S this cable runs from the device down to the driver footwell, where the OBD-C adapter plugs into the OBD2 port.

The cleanest way to run the cable:

1. Route the cable up the A-pillar inside the pillar cover. Remove the airbag cover trim on the A-pillar (one or two pry points at the base), tuck the cable behind it, and reattach.
2. Continue across the top of the windshield by sliding the cable under the headliner. A plastic pry tool works well here — lift the edge of the headliner and push the cable in as you go toward the mirror base.
3. Drop the cable down the front of the windshield at the mirror base, emerging near the bottom center of the glass.
4. Route down through the door seal area to the footwell.

Make sure the USB-C connector is pushed fully into the back of the device — it is a tight fit and partial connection is a common cause of "car offline" errors.

All cables should be secured so they don't hang loose or rub against sharp trim edges.

Panda LED indicators

The panda is the embedded CAN interface inside the comma device (integrated on comma 3/3X, not a separate box). The LED on the back of the device indicates its state:

LED	Meaning
Red (fades in/out)	Power heartbeat — normal
White	CAN send enabled
Blue (static)	CAN traffic detected
Blue (fades in/out)	Power-saving mode
Green (fast)	Bad firmware or flashing in progress

Why the comma two and EON are no longer supported

Earlier devices — the EON (based on the Qualcomm Snapdragon 821, sold until around 2020) and the comma two (same platform, sold until 2022) — ran older versions of openpilot and the Tinkla software that preceded NAP. Support for both ended when comma.ai dropped them from mainline openpilot, and the NAP codebase requires features only present in comma 3-era firmware.

The EON also had a separate panda device (usually a Black Panda) connected by USB, and required the EPAS harness to physically wire into the steering ECU. None of that is needed with the comma 3/3X connected at the OBD2 port. The full history of EON-era hardware — the Tinkla giraffe, the EPAS harness, the OBD-C adapter — is documented at /history/eon-era-hardware.

If you have a comma two or EON and want to run NAP, the upgrade path is to replace the device with a comma 3 or comma 3X.