protocol/com.neurotec.brainaccess.protocol

Package-level declarations

Types

Channel type strings of the BrainAccess Board LSL contract (v1), in their canonical spelling. Board and the SDK classify columns by these exact strings.

ChannelUnit

object ChannelUnit

Channel unit strings of the BrainAccess Board LSL contract (v1).

DecodeState

class DecodeState(var lastSample: Int = 0, var batteryPct: Float = -1.0f, var anchorOnNextPacket: Boolean = false, var counterJumps: Long = 0, var stalePackets: Long = 0)

Mutable per-device decode state carried across packets (sample cursor and battery level).

DeviceConfig

data class DeviceConfig(val model: DeviceModel, val channels: List<String>, val gain: List<Int>, val bias: List<Boolean>, val active: List<Boolean>, val srate: Int, val impedanceMode: ImpedanceMode)

Immutable device configuration.

DeviceHardware

enum DeviceHardware : Enum<DeviceHardware>

Hardware generation of a headset, as the device itself reports it in the Device Information Service Model Number string (0x2A24): a decimal code shared with the BrainAccess C SDK and the device firmware.

DeviceModel

enum DeviceModel : Enum<DeviceModel>

BrainAccess device montages, each with its channel layout and factory defaults; EXG8 (the 8-channel V3 board, advertised as "BA EXG8 ") carries the MINI layout.

EegFrame

class EegFrame(val samples: FloatArray, val accel: FloatArray?, val gyro: FloatArray?, val sampleIndex: Long, val isDummy: Boolean, val batteryPct: Float, val digitalInput: Boolean = false)

One decoded sample (one time-point across all active electrodes), with typed fields for electrodes, IMU, sample index, gap flag and battery.

EegPositions

object EegPositions

Electrode

data class Electrode(val channel: String, val x: Float, val y: Float, val z: Float)

10-5 / 10-20 electrode coordinates, ported as reference data for consumers (montage, visualization).

Electrodes

object Electrodes

What every BrainAccess cap and HALO electrode is made of, as the Board contract publishes it (hardware of each channel, cap node). The forehead electrodes PAD_CHANNELS are gold pads, every other electrode has spring-loaded pins.

GattUuids

object GattUuids

GATT service / characteristic / descriptor UUIDs for BrainAccess devices.

ImpedanceMode

enum ImpedanceMode : Enum<ImpedanceMode>

Electrode impedance measurement mode — config blob byte 0 (codes are the wire contract, shared with the BrainAccess C SDK). Non-OFF modes make the device inject a small AC test current through the bias electrodes at the given frequency; the device computes electrode impedance on-chip (Ohm's law, Z = Vpp / I) and streams it directly in kΩ.

OtaControl

object OtaControl

Firmware-update control opcodes for GattUuids.FIRMWARE_UPDATE_SERVICE (vendor OTA contract).

OutputMode

enum OutputMode : Enum<OutputMode>

What the device streams on its EEG channels — the one-byte value of the output-mode characteristic (GattUuids.OUTPUT_MODE_CHARACTERISTIC); codes are the wire contract, shared with the BrainAccess C SDK. Firmware 3.7.0 and later expose the characteristic; older firmware has none and always streams NORMAL.

PacketCodec

object PacketCodec

Wire codec for BrainAccess stream packets and the channel-config blob.

TimeSyncBlock

object TimeSyncBlock

Wire protocol v1 of the time-sync characteristic (GattUuids.TIME_SYNC_CHARACTERISTIC, firmware 3.8.0+), shared with the device firmware. The device builds the 20-byte value inside its read handler from its own clock and the sample it numbered last, so one timed read ties the host's clock, the device's clock and the ADS1299 sample counter together (see TimeSync in :core). Little-endian:

TimeSyncReply

data class TimeSyncReply(val flags: Int, val streamGen: Int, val seq: Int, val sampleNumber: Long, val sampleAgeUs: Long, val tNowUs: Long, val connInterval: Int)

One decoded reply of GattUuids.TIME_SYNC_CHARACTERISTIC (wire protocol v1, firmware 3.8.0+). See TimeSyncBlock for the byte layout. Unsigned wire fields are widened so every value is non-negative: 8- and 16-bit fields are Int, 32-bit fields are Long.

Properties

ADC_PRECISION_BITS

const val ADC_PRECISION_BITS: Int = 24

ADC resolution of every BrainAccess amplifier (ADS1299), bits.

ADXL343_COUNTS_PER_G

const val ADXL343_COUNTS_PER_G: Float = 256.0f

ADXL343 as the V2 firmware programs it (DATA_FORMAT = 0, ±2 g, right-justified): 3.9 mg/LSB.

GYRO_FULL_SCALE_DPS

const val GYRO_FULL_SCALE_DPS: Float = 250.0f

ICM-42670-P gyroscope full scale as the firmware programs it (GYRO_UI_FS_SEL = ±250 dps).

ICM42670_COUNTS_PER_G

const val ICM42670_COUNTS_PER_G: Float = 16384.0f

ICM-42670-P at ±2 g full scale, 16-bit two's complement.

STANDARD_GRAVITY

const val STANDARD_GRAVITY: Float = 9.80665f

Standard gravity in m/s² per g.