Initial move to app, scanning and reading basic part info works, updating info starting to work

devices/scanner_serial.py

@@ -0,0 +1,44 @@
+import csv, re, serial
+from typing import Callable, Optional
+
+CTRL_SPLIT_RE = re.compile(rb'[\x1d\x1e\x04]+')  # GS, RS, EOT
+
+def _strip_header_bytes(b: bytes) -> bytes:
+    b = b.strip()
+    if b.startswith(b'\x02'): b = b[1:]          # STX
+    if b.startswith(b'[)>'):  b = b[3:]
+    if b.startswith(b'06'):    b = b[2:]         # format code
+    return b
+
+def _normalize_from_bytes(raw: bytes) -> str:
+    raw = _strip_header_bytes(raw)
+    chunks = [c for c in CTRL_SPLIT_RE.split(raw) if c]
+    flat = b''.join(chunks) if chunks else raw
+    s = flat.decode('ascii', errors='ignore').strip()
+    if s.startswith('06'): s = s[2:]
+    return s
+
+def scan_loop(port: str, baud: int, on_scan: Callable[[str], None]):
+    ser = serial.Serial(port, baud, timeout=2)
+    print(f"Opened {port}. Ready — scan a label.")
+    while True:
+        data = ser.read_until(b'\r')  # adjust to b'\n' if needed
+        if not data: 
+            continue
+        flat = _normalize_from_bytes(data)
+        if flat:
+            on_scan(flat)
+
+def maybe_append_csv(path: Optional[str], fields: dict):
+    if not path: return
+    newfile = not os.path.exists(path)
+    import os
+    with open(path, "a", newline="", encoding="utf-8") as f:
+        w = csv.DictWriter(f, fieldnames=list(fields.keys()))
+        if newfile: w.writeheader()
+        w.writerow(fields)
+
+def read_one_scan(port: str, baud: int, read_terminator: bytes = b'\r') -> str:
+    with serial.Serial(port, baud, timeout=10) as ser:
+        data = ser.read_until(read_terminator)
+        return _normalize_from_bytes(data)