Streaming Biosignals

Once a device reaches the .ready connection state, you can start streaming biosignal data.

Start and Stop Streaming

// Start streaming from a connected device
sdk.startStreaming(deviceId: device.id)

// Stop streaming
sdk.stopStreaming(deviceId: device.id)

Stream States

Each device tracks its streaming state independently:

.idle → .starting → .streaming
                   → .stopping → .idle
                   → .stalled
                   → .unsupported

State	Description
.idle	Not streaming
.starting	Stream initialization in progress
.streaming	Actively receiving biosignal data
.stopping	Teardown in progress
.stalled	Stream interrupted (e.g., temporary signal loss)
.unsupported	Device does not support streaming

Receiving Samples

Biosignal samples arrive as .sample events on the SDK's event publisher:

sdk.events.sink { event in
    if case .sample(let deviceId, let sample) = event {
        print("Signal: \(sample.signalName)")

        switch sample.data {
        case .waveform(let values):
            // Array of sample points (e.g., ECG, PPG, EDA waveforms)
            print("  \(values.count) samples")
        case .scalar(let value):
            // Single value (e.g., heart rate, temperature, SpO2)
            print("  Value: \(value)")
        }
    }
}

Signal Types

The BioSample type includes convenience properties for identifying signal types:

Property	Signal	Data type
sample.isECG	Electrocardiogram	.waveform
sample.isPPG	Photoplethysmography	.waveform
sample.isEDA	Electrodermal activity	.waveform
sample.isTemp	Skin temperature	.scalar
sample.isHeartRate	Heart rate (BPM)	.scalar
sample.isSpO2	Blood oxygen saturation	.scalar

sdk.events.sink { event in
    if case .sample(_, let sample) = event {
        if sample.isHeartRate, let bpm = sample.scalarValue {
            print("Heart rate: \(bpm) BPM")
        }
        if sample.isECG, let waveform = sample.waveform {
            // Feed to BioECGChart or your own visualization
            updateChart(waveform)
        }
    }
}

Auto-Stream

Enable auto-stream on a device to automatically start streaming whenever the device connects (including reconnections):

sdk.setAutoStream(deviceId: device.id, enabled: true)

// Check current setting
let isAuto = sdk.autoStreamEnabled(deviceId: device.id)

Data Delivery

The SDK buffers all biosignal data locally and uploads it to the AnyBio platform automatically. Data is persisted across app restarts, so no samples are lost even during network interruptions or app termination.