Connect a headset#

The device list is the app’s home screen — its title bar reads BrainAccess. It is where you find headsets over Bluetooth, connect to them, reconnect to ones you have used before, and open a connected headset’s Config to set sample rate, gain, channels and electrode labels. You land here when the app opens, and every other screen returns you here.

Top bar#

Control	What it does
Brightness/sun/moon icon	Cycles the app theme: System → Light → Dark → System. Remembered.
⋮ (More) → About	App name, version, a one-line description, and Open-source licences

Bottom bar#

Control	What it does
Scan / Stop scan	Starts or stops a Bluetooth scan. A spinner runs while scanning. Disabled while Bluetooth is off.
Recordings	Opens the recordings and snapshots browser (see Recordings and review)

You can also pull down the list to start a scan.

Scanning#

The app scans once automatically when you first reach the device list (Bluetooth on, permissions granted, nothing connected or already found). Coming back from another screen does not restart a scan you saw finish.
Every scan stops on its own after 30 seconds. Scanning takes airtime away from headsets that are already streaming, so it is deliberately not left running.
While scanning and nothing is found yet: Looking for devices… with Turn your device on — it appears here automatically.
After the scan ends with nothing found: No devices found with Check the device is charged and nearby, then scan again. and a Scan again button.

Discovered devices#

One card per headset in range, closest first:

headset name (or (unnamed)),
signal-strength bars plus MODEL · -NN dBm,
a Connect button, replaced by a spinner while connecting.

Remembered headsets#

The app remembers your last four headsets. When a remembered headset is not connected and not currently visible in the scan, you get a card showing its name with Tap to reconnect beneath it (Reconnecting… while it works); with more than one, an extra Reconnect all card appears. Each card has an X to forget that headset (or all of them). Tapping a reconnect card connects immediately if the headset is already in range, otherwise it scans for it first. If Bluetooth is off or the permission is missing, the tap takes you through that prompt first.

The connected-headset card#

Once you connect, the headset gets its own card at the top of the list:

BA MAXI 000                                   [ Ready ]
XX:XX:XX:XX:XX:XX · 32 ch
[ 45% ] [ 250 Hz ]                       [ 30/32 good ]
gain 8 · 32/32 active

[ Stream ]   [ ● Rec ]   [ Impedance ]
--------------------------------------------------
Config       Firmware       Disconnect

Line / control	Meaning
Name and Bluetooth address · channel count	Names come from the headset’s own Bluetooth advertisement; there is no rename in the app
Status pill	`Connecting…`, `Discovering…`, `Ready`, `Streaming`, `Recording`, `Updating…`, `Disconnected`, or `Error: …`
Battery chip	Battery percentage, or `—` if not reported yet. Turns amber at 20% or less
Sample-rate chip	The configured rate
N/M good chip (e.g. `30/32 good`)	Appears while streaming: how many electrodes currently read good signal, dotted with the worst band’s colour so a single bad channel still shows red. Updated about once a second; tap it to open Signal quality
Update amber pill	Appears when newer firmware is available. Tap for Firmware updates
`gain N · A/T active`	Amplifier gain and how many channels are switched on
Status line	`streaming`, or `recording · BDF` / `recording · CSV`, plus `⚠ N samples lost` if any data was dropped
Stream	Starts streaming and opens the Live signal viewer
● Rec	One tap: starts streaming and recording
Impedance	Contact check (only when not streaming) — see Contact check
View / Stop / Quality	Shown instead while streaming
Config	Device settings — only while not streaming
Firmware	Firmware and device info — only while not streaming, and only on headsets that support updates (see Firmware updates)
Disconnect	Drops the link. While recording it reads Stop & disconnect and asks first

While a stream runs in the background, a bar above the bottom buttons shows Streaming · (or Streaming N devices) with a REC badge if any device is recording. Tap it to jump back into the Live signal viewer.

Device settings (Config)#

Tap Config on a connected, non-streaming headset.

Setting	Options
Sample rate	HALO, MINI and EXG8: 250 Hz or 500 Hz. MIDI and MAXI: 250 Hz only
Gain (all channels)	1x, 2x, 4x, 6x, 8x, 12x. If the headset currently has different gains per channel the header reads Mixed
Channels	One checkbox per channel. The header shows how many are active
Electrode labels	On cap headsets (MINI, MIDI, MAXI, EXG8) tap a channel’s label to reassign it from the 10-20 set. Labels already used elsewhere are shown as · in use. HALO has fixed, built-in electrodes, so its labels are read-only

Apply writes the configuration to the headset; it is disabled if no channel is active. Cancel changes nothing.

Electrode labels drive everything downstream: the channel rail in the Live signal viewer, the head maps, the LSL channel names and the column/signal names in your recordings. Set them correctly before you record.

Note

On a 32-channel headset, Apply and Cancel sit below the channel list — scroll past every channel row to reach them.