Convert the accelerometer data from the Polar H10 to the format generated by Somnopose, to import into OSCAR.

convert-h10-acc-xyz-to-somnopose.py

#!/usr/bin/python3
#
# Usage:
# ./convert-h10-acc-xyz-to-somnopose.py Polar_H10_9ED9422D_20241005_024048_ACC.txt > output-2024-10-05.csv
#
# OSCAR can import somnopose data, so we convert the Polar H10 data to the format generated by somnopose.
#
# Example in OSCAR (also with data from a Checkme O2 Max): https://i.imgur.com/SDLQJEY.png 

from typing import NamedTuple, List
from datetime import datetime
import sys
import math

"""
$ head -5 Polar_H10_9ED9422D_20241005_024048_ACC.txt
Phone timestamp;sensor timestamp [ns];X [mg];Y [mg];Z [mg]
2024-10-05T02:40:51.687;599616285252552704;-757;106;640
2024-10-05T02:40:51.727;599616285292552704;-757;107;639
2024-10-05T02:40:51.767;599616285332552704;-757;107;641
2024-10-05T02:40:51.807;599616285372552704;-757;112;641
"""

class Data(NamedTuple):
    phone_timestamp: str
    sensor_timestamp_nanos: int
    dt: datetime
    X: int
    Y: int
    Z: int
    pitch: float
    roll: float

def main():
    filename = sys.argv[1]
    data = load_data(filename)
    print_data(data)


def print_data(data):
    prev_ts = 0
    print("Timestamp,Orientation,Inclination")
    for d in data:
        ts_secs = int(d.dt.timestamp()) - 978307200  # convert unix epoch time to "iOS time"
        if prev_ts == ts_secs:
            continue # only output one value per second
        prev_ts = ts_secs
        print(f"{ts_secs},{d.roll:.2f},{d.pitch:.2f}")


def load_data(filename):
    data: List[Data] = []

    with open(filename) as fin:
        for line in fin:
            parts = line.split(";")
            if len(parts) != 5:
                print(f"line doesn't match expected format! got: {line}, {parts}", file=sys.stderr)
                continue
            if parts[0][0] != "2":
                print(f"skipping non-date line: {parts}", file=sys.stderr)
                continue

            # Phone timestamp;sensor timestamp [ns];X [mg];Y [mg];Z [mg]
            # 2024-10-05T02:40:51.687;599616285252552704;-757;106;640
            
            phone_ts = parts[0].split(".")[0] # 2024-10-05T02:40:51
            sensor_ts_nanos = int(parts[1]) # 599616285252552704 (not actually used)
            X, Y, Z = int(parts[2]), int(parts[3]), int(parts[4]) # -757;106;640
            pitch, roll = calculate(X, Y, Z)

            dt = datetime.strptime(phone_ts, "%Y-%m-%dT%H:%M:%S")
            d = Data(phone_ts, sensor_ts_nanos, dt, X, Y, Z, pitch, roll)
            data.append(d)
    return data

def calculate(X, Y, Z):
    # from https://stackoverflow.com/a/10320532
    pitch = math.atan2(-X, math.sqrt(Y*Y + Z*Z)) * 180/math.pi 
    roll = math.atan2(Y, Z) * 180 / math.pi
    return (pitch, roll)

if __name__ == "__main__":
    main()