Initial biometric data receiver implementation

receive.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+"""
+Pulse oximeter UDP listener.
+Receives heart-rate (BPM) and SpO2 readings from the device and prints them.
+Run:  python3 receive.py
+"""
+
+import socket
+import datetime
+import json
+import csv
+import sys
+import os
+
+HOST = "0.0.0.0"
+PORT = 5005
+
+def parse_payload(raw: bytes) -> dict | None:
+    """Try JSON first, then common key=value or CSV formats."""
+    text = raw.decode(errors="replace").strip()
+    if not text:
+        return None
+
+    # JSON
+    if text.startswith("{"):
+        try:
+            return json.loads(text)
+        except json.JSONDecodeError:
+            pass
+
+    # key=value pairs (e.g. BPM=72,SPO2=98)
+    if "=" in text:
+        try:
+            return dict(part.split("=", 1) for part in text.replace(";", ",").split(",") if "=" in part)
+        except Exception:
+            pass
+
+    # Bare CSV: treat first field as BPM, second as SpO2
+    parts = text.split(",")
+    if len(parts) >= 2 and all(p.strip().lstrip("-").isdigit() for p in parts[:2]):
+        return {"BPM": parts[0].strip(), "SpO2": parts[1].strip()}
+
+    # Unknown — return raw
+    return {"raw": text}
+
+
+def main():
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind((HOST, PORT))
+
+    log_path = os.path.join(os.path.dirname(__file__), "readings.csv")
+    write_header = not os.path.exists(log_path)
+    log_file = open(log_path, "a", newline="")
+    writer = csv.writer(log_file)
+    if write_header:
+        writer.writerow(["timestamp", "bpm", "spo2", "raw"])
+
+    print(f"Listening on UDP {HOST}:{PORT}  |  Logging to {log_path}")
+    print(f"{'TIME':12}  {'BPM':>6}  {'SpO2 %':>7}  STATUS")
+    print("-" * 52)
+
+    try:
+        while True:
+            data, addr = sock.recvfrom(4096)
+            ts = datetime.datetime.now()
+            parsed = parse_payload(data)
+
+            def _get(d, *keys):
+                for k in keys:
+                    if k in d:
+                        return d[k]
+                return None
+
+            bpm_raw  = _get(parsed, "bpm", "BPM", "heartrate")
+            spo2_raw = _get(parsed, "spo2", "SPO2", "SpO2", "oxygen")
+            raw      = parsed.get("raw", "")
+
+            bpm_val  = int(bpm_raw)  if bpm_raw  is not None else None
+            spo2_val = int(spo2_raw) if spo2_raw is not None else None
+
+            no_finger = (bpm_val is not None and bpm_val < 0) or \
+                        (spo2_val is not None and spo2_val < 0)
+
+            bpm_str  = "---" if (bpm_val  is None or bpm_val  < 0) else str(bpm_val)
+            spo2_str = "---" if (spo2_val is None or spo2_val < 0) else str(spo2_val)
+            status   = "No finger" if no_finger else (f"({raw})" if raw else "OK")
+
+            print(f"{ts.strftime('%H:%M:%S.%f')[:12]}  {bpm_str:>6}  {spo2_str:>7}  {status}")
+            sys.stdout.flush()
+
+            # Log only rows where valid readings exist
+            log_bpm  = bpm_val  if (bpm_val  is not None and bpm_val  >= 0) else ""
+            log_spo2 = spo2_val if (spo2_val is not None and spo2_val >= 0) else ""
+            writer.writerow([ts.isoformat(), log_bpm, log_spo2, data.decode(errors="replace").strip()])
+            log_file.flush()
+
+    except KeyboardInterrupt:
+        print("\nStopped.")
+    finally:
+        sock.close()
+        log_file.close()
+
+
+if __name__ == "__main__":
+    main()