Move relay to GPIO5, harden relay script, add monitor_speed

relay

@@ -1,3 +1,47 @@
-#!/bin/bash
-[ $# -ne 1 ] || [ "$1" != "0" -a "$1" != "1" ] && { echo "Usage: relay 0|1"; exit 1; }
-python3 -c "import serial; s=serial.Serial('/dev/cu.usbserial-2110',115200,timeout=2); s.write(b'$1'); print(s.read(10).decode())"
+#!/usr/bin/env python3
+"""Toggle the USB relay via serial: ./relay 1|0 [serial_port]."""
+import sys
+import serial
+
+DEFAULT_PORT = "/dev/cu.usbserial-2110"
+
+def main() -> int:
+    if len(sys.argv) not in (2, 3) or sys.argv[1] not in ("0", "1"):
+        print(f"Usage: {sys.argv[0]} 0|1 [serial_port]", file=sys.stderr)
+        return 1
+    command = sys.argv[1]
+    port = sys.argv[2] if len(sys.argv) == 3 else DEFAULT_PORT
+    try:
+        # dtr/rts expliciet uit vóór open: voorkomt (of beperkt) de CH340
+        # auto-reset (DTR->RST) bij het openen van de poort. pyserial 3.5
+        # accepteert geen dtr=/rts= kwargs in de constructor, maar de
+        # states worden wél geëerd door open().
+        s = serial.Serial()
+        s.port = port
+        s.baudrate = 115200
+        s.timeout = 2
+        s.dtr = False
+        s.rts = False
+        s.open()
+    except serial.SerialException as exc:
+        print(f"ERROR: cannot open {port}: {exc}", file=sys.stderr)
+        return 1
+    try:
+        # Als het board toch reset bij open: wacht op de boot-banner en
+        # gooi die weg, zodat de reply niet vervuild raakt. Geen banner
+        # binnen 2 s (timeout, readline geeft b"") = geen reset: door.
+        s.readline()
+        s.reset_input_buffer()
+        s.write(command.encode())
+        s.flush()
+        reply = s.readline().decode(errors="replace").strip()
+    finally:
+        s.close()
+    if reply in ("ON", "OFF"):
+        print(reply)
+        return 0
+    print(f"ERROR: no valid reply from board (got {reply!r})", file=sys.stderr)
+    return 1
+
+if __name__ == "__main__":
+    sys.exit(main())