Expand description
GATT UUIDs, sampling constants, and sensor scaling factors for Hermes V1 EEG headsets.
All UUIDs belong to the Hermes vendor namespace
9fa4XXXX-4967-11e5-a151-0002a5d5c51b.
Constants§
- ACC_
SENSITIVITY - Accelerometer sensitivity: 0.061 mg/LSB → g.
- ADS1299_
GAIN - Default ADS1299 amplifier gain.
- ADS1299_
VREF - Default ADS1299 reference voltage in volts.
- COMPASS_
CHARACTERISTIC - Compass (magnetometer-only) characteristic (defined by the device but not
currently used — magnetometer data arrives via
MOTION_CHARACTERISTIC). - EEG_
CHANNEL_ NAMES - Human-readable EEG channel labels.
- EEG_
CONFIG_ CHARACTERISTIC - EEG configuration characteristic — used for both writes (commands) and notifications (config responses).
- EEG_
DATA_ CHARACTERISTIC - EEG data characteristic — notifications carry packed 24-bit ADS1299 samples.
- EEG_
FRAME_ BYTES - Bytes per single multi-channel EEG sample frame (8 channels × 3 bytes).
- EEG_
FREQUENCY - EEG sample rate in Hz (250 samples per second per channel).
- EEG_
NUM_ CHANNELS - Number of EEG channels on the ADS1299 (8 differential inputs).
- EEG_
SERVICE_ UUID - Primary EEG GATT service UUID.
- EVENT_
CHARACTERISTIC - Event (button press) characteristic — notifications on user interaction.
- EVENT_
SERVICE_ UUID - Event (button) GATT service UUID.
- GYRO_
CHARACTERISTIC - Gyroscope-only characteristic (defined by the device but not currently used
— gyro data arrives via
MOTION_CHARACTERISTIC). - GYRO_
SENSITIVITY - Gyroscope sensitivity: 8.75 mdps/LSB → dps (degrees per second).
- MAG_
SENSITIVITY - Magnetometer sensitivity: 0.14 mgauss/LSB → gauss.
- MOTION_
CHARACTERISTIC - 9-DOF motion characteristic — accel + gyro + magnetometer in one notification.
- PACKET_
INDEX_ MODULUS - Packet index range (0..=127). The index wraps from 127 → 0.
Functions§
- ads1299_
to_ microvolts - Convert a raw signed 24-bit ADS1299 value to microvolts.
- cmd_
read_ register - Build the 4-byte “read register” command (register address 0x0195).
- cmd_
start_ streaming - Build the 4-byte “start streaming” command.
- cmd_
test_ mode - Build the 4-byte “test mode” command.