added UDSonLIN example

Author: dragonlock2

examples/pyjabi/UDSonLIN.py

@@ -0,0 +1,128 @@
+import jabi
+import time
+
+class UDSonLIN:
+    COMMANDER_ID = 0x3C
+    RESPONDER_ID = 0x3D
+
+    def __init__(self, dev, nad, rate=19200):
+        dev.lin_set_mode(jabi.LINMode.COMMANDER)
+        dev.lin_set_rate(rate)
+        dev.lin_set_filter(self.RESPONDER_ID, 8, jabi.LINChecksum.CLASSIC)
+        self.dev = dev
+        self.nad = nad
+
+    # low-level
+    def _write_raw(self, data):
+        assert(len(data) == 8)
+        self.dev.lin_write(jabi.LINMessage(self.COMMANDER_ID, list(data), jabi.LINChecksum.CLASSIC))
+
+    def _read_raw(self):
+        msg = self.dev.lin_read(self.RESPONDER_ID)
+        assert(msg.data[0] == self.nad)
+        assert((msg.data[1] >> 4) <= 2)
+        return bytes(msg.data)
+
+    # transport layer
+    def _write(self, data):
+        assert(len(data) <= 4095)
+        if len(data) <= 6:
+            # SF
+            self._write_raw(bytes([
+                self.nad,
+                0x00 | len(data),
+                *data,
+                *(b'\xff' * (6 - len(data)))
+            ]))
+        else:
+            # FF
+            self._write_raw(bytes([
+                self.nad,
+                0x10 | (len(data) // 256),
+                len(data) % 256,
+                *data[:5]
+            ]))
+            data = data[5:]
+            # CF
+            fc = 1
+            while data:
+                self._write_raw(bytes([
+                    self.nad,
+                    0x20 | fc,
+                    *data[:6],
+                    *(b'\xff' * (0 if len(data) >= 6 else (6 - len(data))))
+                ]))
+                fc = (fc + 1) % 16
+                data = data[6:]
+
+    def _read(self):
+        pkt = self._read_raw()
+        assert((pkt[1] >> 4) <= 1)
+        if (pkt[1] >> 4) == 0:
+            # SF
+            length = pkt[1] & 0x0F
+            assert(length <= 6)
+            return pkt[2:2+length]
+        else:
+            # FF
+            length = ((pkt[1] & 0x0F) << 8) | pkt[2]
+            data = pkt[3:]
+            length -= 5
+            # CF
+            fc = 1
+            while length:
+                pkt = self._read_raw()
+                assert((pkt[1] >> 4) == 2)
+                assert((pkt[1] & 0x0F) == fc)
+                data += pkt[2:2+min(6,length)]
+                fc = (fc + 1) % 16
+                length -= min(6,length)
+            return data
+
+    # UDS layer
+    # basic info - https://en.wikipedia.org/wiki/Unified_Diagnostic_Services
+    # read/write DID - https://embetronicx.com/tutorials/automotive/uds-protocol/data-transmission-in-uds-protocol
+    # routine format - https://embedclogic.com/uds-protocol/uds-remote-activation-of-routine/
+    # routine subfunc - https://piembsystech.com/uds-protocol/
+    def _routine(self, id, subfunc, data, delay):
+        self._write(b'\x31' + subfunc + id.to_bytes(2, 'big') + data)
+        time.sleep(delay)
+        pkt = self._read()
+        assert(len(pkt) >= 4)
+        assert(pkt[0] == 0x71)
+        assert(pkt[1] == subfunc[0])
+        assert(int.from_bytes(pkt[2:4], 'big') == id)
+        return pkt[4:]
+
+    def routine_start(self, id, data, delay=0.0):
+        return self._routine(id, b'\x01', data, delay)
+    
+    def routine_stop(self, id, data, delay=0.0):
+        return self._routine(id, b'\x02', data, delay)
+    
+    def routine_request_results(self, id, data, delay=0.0):
+        return self._routine(id, b'\x03', data, delay)
+
+    def read_did(self, id, delay=0.0):
+        self._write(b'\x22' + id.to_bytes(2, 'big'))
+        time.sleep(delay)
+        pkt = self._read()
+        assert(len(pkt) >= 3)
+        assert(pkt[0] == 0x62)
+        assert(int.from_bytes(pkt[1:3], 'big') == id)
+        return pkt[3:]
+    
+    def write_did(self, id, data, delay=0.0):
+        self._write(b'\x2e' + id.to_bytes(2, 'big') + data)
+        time.sleep(delay)
+        pkt = self._read()
+        assert(len(pkt) == 3)
+        assert(pkt[0] == 0x6e)
+        assert(int.from_bytes(pkt[1:3], 'big') == id)
+
+"""
+example usage:
+
+uds = UDSonLIN(jabi.USBInterface.list_devices()[0], 0x00)
+uds.read_did(0x0000)
+"""