Anchor Recorder
Stereo video + IMU straight to the microSD card. Recording needs no computer and no setup.
1Record
Plug the recorder's USB-C cable into a power bank. It starts recording by itself within about a minute.
one short blink per second = recording.
To stop, unplug it. Everything is kept except up to the last ~10 seconds.
2Copy recordings
Plug the same cable into a computer. Recording stops and a drive called ANCHOR appears.
Copy the sessions folder. Steps for your computer
3Check & focus
While it is plugged into a computer, connect here to see its status, its recordings and a live view for focusing.
Connect to your recorder
- Plug the recorder into this computer and wait until its light stays on (under a minute).
- Click Connect and choose Anchor Recorder in the list, then Connect.
This page talks to the recorder over the USB cable. Nothing is uploaded; video stays on your computer. After the first time, it reconnects by itself.
Before Record now, eject the ANCHOR drive on this computer, since recording takes the card back. Normal use needs no button: plugging into a power bank records.
To focus: turn one lens slowly and stop where its bar is fullest (green). Each bar compares an eye only with its own best, so point the camera at something detailed and keep it still.
Recordings on the card
| Session | Length | Result |
|---|---|---|
| Loading… | ||
A new session starts every time the recorder powers on. Names are unit_boot_n; a time suffix appears when the clock was set.
Copy recordings to your computer
- Plug the recorder into the Mac. If macOS asks “Allow accessory to connect?”, click Allow. (If you were slow to click, that is fine: the recorder switches to the drive a few seconds after you allow it.)
- Within about a minute ANCHOR appears in the Finder sidebar under Locations.
- Drag the
sessionsfolder (or single session folders) to your Mac. - Eject ANCHOR, then unplug.
The drive is read-only, so nothing on it can be changed or deleted by accident. If you unplug without ejecting, macOS shows “Disk Not Ejected Properly”. It is harmless here.
- Plug the recorder into the PC. Within about a minute File Explorer shows a drive called ANCHOR.
- Copy the
sessionsfolder to your PC. - Click Safely Remove Hardware → ANCHOR, then unplug.
If Windows offers to “scan and fix” the drive, choose Continue without scanning; the drive is read-only and does not need fixing. Windows may also list an extra network adapter or serial port for the recorder. That is the connection this page uses.
- Plug the recorder in. Most desktops mount it at
/media/$USER/ANCHORwithin about a minute. cp -r /media/$USER/ANCHOR/sessions ~/anchor/(orrsync -ato resume a copy).
No desktop automount? lsblk -f shows the ANCHOR partition; sudo mount -o ro /dev/sdX /mnt (the drive has no partition table; mount the disk itself). It is exFAT (built into Linux 5.7 and later).
How long it takes: roughly 15 minutes per hour of recording. One hour of stereo video is about 11 GB and the cable copies at about 12 MB/s (USB 2.0). For many hours of footage, a USB 3 microSD card reader is several times faster.
What the light means
| Light | Meaning | What to do |
|---|---|---|
| Off | No power | Check the cable and that the power bank is on (a 5 V, 2 A or stronger port). |
| Double blink, repeating | Starting up | Wait. It records (on a power bank) or shows the drive (on a computer) within a minute. |
| One short blink per second | Recording | Nothing. Unplug to stop. |
| Steady on | Connected to a computer (not recording), or recording stopped because the card is full | Copy files, or connect on this page to see which. |
| Fast flashing | Problem: usually the camera is not found | Check the camera cable, then plug into a computer and connect here; the page says what is wrong. |
Using the data
Each session folder holds the left and right videos (H.264, 1632×1264, 30 fps, one file per minute), one row per camera frame, and the IMU samples. Left and right come from the same camera frame and share one timestamp.
IMU timing: the camera delivers IMU samples inside its video frames, in bursts. Each IMU row carries the timestamp of the frame it arrived in (arrival time, not sample time); a per-sample counter is included for finer alignment. Raw units and axis directions are still awaiting confirmation from the camera maker. See DATA-SCHEMA.md › IMU.
Dates: the recorder has no clock battery. Recordings made on a power bank have no calendar date; their order is in the folder name (unit_boot_n: power-on count, then recording number). Sessions recorded while connected to this page get the date from your computer.
- anchor_load.py: loads a session in Python and pairs left, right, frame and IMU rows by timestamp (needs
ffmpeg).python3 anchor_load.py sessions/<session> - anchor-check.py: checks a copied session for dropped frames and gaps and prints PASS or FAIL.
- DATA-SCHEMA.md: every file and column. The same files are also on the ANCHOR drive.
How to know a recording is good
- After copying, run
python3 anchor-check.py sessions/<session>(needs Python 3.9+ and ffmpeg). It prints PASS or FAIL, lists any dropped frames or gaps, and savesSHA256SUMSandcheck.jsonin the session folder. - Later, or on another machine,
python3 anchor-check.py --verify-copy sessions/<session>confirms that no file changed since.
Lighting: the camera's anti-flicker is set for 50 Hz mains; the setting the camera reported is saved in each session's manifest.json.
If something is not right
The ANCHOR drive does not appear
- Wait a full minute after plugging in; the recorder boots first.
- Use a USB-C data cable (some charging cables have no data wires). The cable that came with the recorder works.
- Plug directly into the computer, not through a monitor or unpowered hub.
- macOS: if you clicked Don’t Allow earlier, unplug and plug in again, or allow it in System Settings → Privacy & Security → Allow accessories to connect.
“Anchor Recorder” is not in the Connect list
- Wait until the light stays on, then click Connect again.
- Close other programs that may be using the recorder's serial port (a terminal, another tab of this page).
- Linux: Chrome needs permission for serial ports. Run
sudo usermod -aG dialout $USER, then log out and in. If ModemManager is installed, it can grab the port for a few seconds after plugging in; wait 10 seconds and try again. - Use Chrome or Edge on a computer. Safari, Firefox and phones cannot connect to USB devices from a web page, but you can still record and copy files without this page.
It does not record on the power bank
- Some power banks switch off when the current is low; use one that stays on, or press its button once after plugging in.
- If the light flashes fast, connect on this page to see the reason.
A session shows FAIL or “interrupted”
“Interrupted” means the power was removed while recording. That is normal when you stop by unplugging; everything up to the last ~10 seconds is kept, and anchor-check accepts a short last file for these sessions. FAIL means the check found dropped frames or gaps above the limits. Please send us the session's manifest.json, events.jsonl and health.jsonl (small text files).