public static double[] DecodePPGSamples(string bits)
{
// Each packet contains a 16 bit timestamp, followed by 6, 24-bit samples.
double[] samples = new double[Constants.MUSE_PPG_SAMPLE_COUNT];
for (int i = 0; i < Constants.MUSE_PPG_SAMPLE_COUNT; i++)
{
samples[i] = PacketConversion.ToUInt24(bits, 16 + (i * 24)); // Initial offset by 16 bits for the timestamp.
}
return(samples);
}
public static double[] DecodeEEGSamples(string bits)
{
// Each packet contains a 16 bit timestamp, followed by 12, 12-bit samples.
double[] samples = new double[12];
for (int i = 0; i < 12; i++)
{
samples[i] = PacketConversion.ToUInt12(bits, 16 + (i * 12)); // Initial offset by 16 bits for the timestamp.
samples[i] = (samples[i] - 2048d) * 0.48828125d; // 12 bits on a 2 mVpp range.
}
return(samples);
}
private double[] GetTimeSamples(string bits)
{
// Extract our 12, 12-bit samples.
double[] timeSamples = new double[Constants.MUSE_SAMPLE_COUNT];
for (int i = 0; i < Constants.MUSE_SAMPLE_COUNT; i++)
{
timeSamples[i] = PacketConversion.ToFakeUInt12(bits, 16 + (i * 12)); // Initial offset by 16 bits for the timestamp.
timeSamples[i] = (timeSamples[i] - 2048d) * 0.48828125d; // 12 bits on a 2 mVpp range.
}
return(timeSamples);
}
public static double[,] DecodeGyroscopeSamples(string bits)
{
// Each packet contains a 16 bit timestamp, followed by 9, 16 bit values representing 3 "xyz" samples.
double[,] samples = new double[Constants.MUSE_GYROSCOPE_SAMPLE_COUNT, Constants.MUSE_GYROSCOPE_CHANNEL_COUNT];
for (int i = 0; i < Constants.MUSE_GYROSCOPE_SAMPLE_COUNT; i++)
{
for (int j = 0; j < Constants.MUSE_GYROSCOPE_CHANNEL_COUNT; j++)
{
samples[i, j] = PacketConversion.ToInt16(bits, 16 + (((i * Constants.MUSE_GYROSCOPE_CHANNEL_COUNT) + j) * 16)); // Initial offset by 16 bits for the timestamp.
samples[i, j] *= Constants.MUSE_GYROSCOPE_SCALE_FACTOR;
}
}
return(samples);
}
public static double[] DecodeTelemetrySamples(string bits)
{
// Each packet contains a 16 bit timestamp, followed by 4, 16-bit values representing battery, "fuel_gauge?", adc voltage, and temperature.
double[] samples = new double[Constants.MUSE_TELEMETRY_CHANNEL_COUNT];
for (int i = 0; i < Constants.MUSE_TELEMETRY_CHANNEL_COUNT; i++)
{
samples[i] = PacketConversion.ToUInt16(bits, 16 + (i * 16)); // Initial offset by 16 bits for the timestamp.
}
// The following conversion are from muse-lsl (inside muse.py). Not sure how accurate this info is. 2/13/2020.
// Battery.
samples[0] = samples[0] / 512;
// Fuel guage...
samples[1] = samples[1] * 2.2d;
return(samples);
}
private async void Channel_ValueChanged(GattCharacteristic sender, GattValueChangedEventArgs args)
{
if (isStreaming)
{
string bits = GetBits(args.CharacteristicValue);
ushort museTimestamp = PacketConversion.ToUInt16(bits, 0); // Zero bit offset, since first 16 bits represent Muse timestamp.
MuseSample sample;
lock (sampleBuffer)
{
if (!sampleBuffer.ContainsKey(museTimestamp))
{
sample = new MuseSample();
sampleBuffer.Add(museTimestamp, sample);
sample.BaseTimestamp = TimestampFormat.GetNow(); // This is the real timestamp, not the Muse timestamp which we use to group channel data.
sample.BasetimeStamp2 = TimestampFormat.GetType() != TimestampFormat2.GetType() ?
TimestampFormat2.GetNow() // This is the real timestamp (format 2), not the Muse timestamp which we use to group channel data.
: sample.BasetimeStamp2 = sample.BaseTimestamp; // Ensures they are equal if using same timestamp format.
}
else
{
sample = sampleBuffer[museTimestamp];
}
// Get time samples.
sample.ChannelData[sender.Uuid] = GetTimeSamples(bits);
}
// If we have all 5 channels, we can push the 12 samples for each channel.
if (sample.ChannelData.Count == channelCount)
{
await LSLPushChunk(sample);
lock (sampleBuffer)
sampleBuffer.Remove(museTimestamp);
}
}
}
