Add waagen simulator

waagen/simulator.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+# SysTec IT3000A uses CRC16-modbus
+
+import argparse
+import socket
+import datetime
+import random
+import time
+import crcmod.predefined
+
+
+IDENT_NR = 0
+
+
+def crc16_modbus(data: bytes) -> int:
+    crc = crcmod.predefined.Crc('modbus')
+    crc.update(data)
+    return int(crc.hexdigest(), 16)
+
+
+def handle_systec_it3000a(req: bytes) -> bytes:
+    global IDENT_NR
+
+    if not req.startswith(b'<') or not req.endswith(b'>'):
+        return b'<01>\r\n'
+    req = req[1:-1]
+
+    if len(req) > 3:
+        return b'<02>\r\n'
+    if req.startswith(b'RN'):
+        incr = True
+    elif req.startswith(b'RM'):
+        incr = False
+    else:
+        return b'<02>\r\n'
+
+    if incr:
+        time.sleep(random.randint(0, 40) / 10.0)
+
+    gew = random.randint(40, 4000)
+    m = random.randint(1, 10)
+    match m:
+        case 1:
+            return b'<12>\r\n'
+        case 2:
+            incr = False
+            gew = 0
+
+    if incr:
+        IDENT_NR += 1
+    now = datetime.datetime.now()
+    data = f'0000{now:%d.%m.%y%H:%M}{IDENT_NR if incr else 0:4}1{gew:8}{0:8}{gew:8}kg   {1:3}'.encode('ascii')
+    return b'<' + data + f'{crc16_modbus(data):8}'.encode('ascii') + b'>\r\n'
+
+
+def main() -> None:
+    s = socket.socket()
+    s.bind(('0.0.0.0', 1234))
+    s.listen()
+    print('Ready for connections')
+
+    while True:
+        c, a = s.accept()
+        print(f'Accepting connection from {a}')
+        try:
+            while True:
+                req = c.recv(1024)
+                print(req.decode('ascii'), end='')
+                res = handle_systec_it3000a(req)
+                print(res.decode('ascii'), end='')
+                c.send(res)
+        except:
+            pass
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    args = parser.parse_args()
+    main()