Crossfire parsing script updated

radio/util/crossfire-parse.py

@@ -33,8 +33,48 @@ def dump(data, maxLen=None):
         data = data[:maxLen]
     return " ".join("{:02x}".format(c) for c in data)
 
-def CheckCrc(packet):
-    return True
+
+# CRC8 implementation with polynom = x^8+x^7+x^6+x^4+x^2+1 (0xD5)
+crc8tab = [
+    0x00, 0xD5, 0x7F, 0xAA, 0xFE, 0x2B, 0x81, 0x54,
+    0x29, 0xFC, 0x56, 0x83, 0xD7, 0x02, 0xA8, 0x7D,
+    0x52, 0x87, 0x2D, 0xF8, 0xAC, 0x79, 0xD3, 0x06,
+    0x7B, 0xAE, 0x04, 0xD1, 0x85, 0x50, 0xFA, 0x2F,
+    0xA4, 0x71, 0xDB, 0x0E, 0x5A, 0x8F, 0x25, 0xF0,
+    0x8D, 0x58, 0xF2, 0x27, 0x73, 0xA6, 0x0C, 0xD9,
+    0xF6, 0x23, 0x89, 0x5C, 0x08, 0xDD, 0x77, 0xA2,
+    0xDF, 0x0A, 0xA0, 0x75, 0x21, 0xF4, 0x5E, 0x8B,
+    0x9D, 0x48, 0xE2, 0x37, 0x63, 0xB6, 0x1C, 0xC9,
+    0xB4, 0x61, 0xCB, 0x1E, 0x4A, 0x9F, 0x35, 0xE0,
+    0xCF, 0x1A, 0xB0, 0x65, 0x31, 0xE4, 0x4E, 0x9B,
+    0xE6, 0x33, 0x99, 0x4C, 0x18, 0xCD, 0x67, 0xB2,
+    0x39, 0xEC, 0x46, 0x93, 0xC7, 0x12, 0xB8, 0x6D,
+    0x10, 0xC5, 0x6F, 0xBA, 0xEE, 0x3B, 0x91, 0x44,
+    0x6B, 0xBE, 0x14, 0xC1, 0x95, 0x40, 0xEA, 0x3F,
+    0x42, 0x97, 0x3D, 0xE8, 0xBC, 0x69, 0xC3, 0x16,
+    0xEF, 0x3A, 0x90, 0x45, 0x11, 0xC4, 0x6E, 0xBB,
+    0xC6, 0x13, 0xB9, 0x6C, 0x38, 0xED, 0x47, 0x92,
+    0xBD, 0x68, 0xC2, 0x17, 0x43, 0x96, 0x3C, 0xE9,
+    0x94, 0x41, 0xEB, 0x3E, 0x6A, 0xBF, 0x15, 0xC0,
+    0x4B, 0x9E, 0x34, 0xE1, 0xB5, 0x60, 0xCA, 0x1F,
+    0x62, 0xB7, 0x1D, 0xC8, 0x9C, 0x49, 0xE3, 0x36,
+    0x19, 0xCC, 0x66, 0xB3, 0xE7, 0x32, 0x98, 0x4D,
+    0x30, 0xE5, 0x4F, 0x9A, 0xCE, 0x1B, 0xB1, 0x64,
+    0x72, 0xA7, 0x0D, 0xD8, 0x8C, 0x59, 0xF3, 0x26,
+    0x5B, 0x8E, 0x24, 0xF1, 0xA5, 0x70, 0xDA, 0x0F,
+    0x20, 0xF5, 0x5F, 0x8A, 0xDE, 0x0B, 0xA1, 0x74,
+    0x09, 0xDC, 0x76, 0xA3, 0xF7, 0x22, 0x88, 0x5D,
+    0xD6, 0x03, 0xA9, 0x7C, 0x28, 0xFD, 0x57, 0x82,
+    0xFF, 0x2A, 0x80, 0x55, 0x01, 0xD4, 0x7E, 0xAB,
+    0x84, 0x51, 0xFB, 0x2E, 0x7A, 0xAF, 0x05, 0xD0,
+    0xAD, 0x78, 0xD2, 0x07, 0x53, 0x86, 0x2C, 0xF9
+]
+
+def crc8(buffer):
+    crc = 0
+    for c in buffer:
+        crc = crc8tab[crc ^ c]
+    return crc
 
 def ParseGPS(payload):
     pass
@@ -95,10 +135,13 @@ parsers = (
 )
 
 def ParsePacket(packet):
-    len = packet[1]
+    length = packet[1]
     command = packet[2]
     payload = packet[3:-1]
     crc = packet[-1]
+    if crc != crc8(packet[2:-1]):
+        print("[%s]" % timeData, dump(packet), "[CRC error]")
+        return
     for id, parser in parsers:
         if id == command:
             print("[%s]" % timeData, dump(packet), parser(payload))
@@ -120,8 +163,8 @@ def ParseData(data):
             continue
         length = crossfireDataBuff[1]
         if length < 2 or length > 0x40:
-            print("Skipped 2 bytes", dump(crossfireDataBuff[:2]))
-            crossfireDataBuff = crossfireDataBuff[2:]
+            print("Skipped 1 bytex", dump(crossfireDataBuff[:1]))
+            crossfireDataBuff = crossfireDataBuff[1:]
             continue
         if len(crossfireDataBuff) < length+2:
             break