wip

panda/examples/can_bit_transition.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python3
+import csv
+import sys
+
+CSV_KEYS = {
+  "logger": {
+    "time": "Time",
+    "message_id": "MessageID",
+    "data": "Message",
+    "bus": "Bus"
+  },
+  "cabana": {
+    "time": "time",
+    "message_id": "addr",
+    "data": "data",
+    "bus": "bus"
+  }
+}
+
+
+class Message():
+  """Details about a specific message ID."""
+
+  def __init__(self, message_id):
+    self.message_id = message_id
+    self.ones = [0] * 64   # bit set if 1 is always seen
+    self.zeros = [0] * 64  # bit set if 0 is always seen
+
+  def printBitDiff(self, other):
+    """Prints bits that transition from always zero to always 1 and vice versa."""
+    for i in range(len(self.ones)):
+      zero_to_one = other.zeros[i] & self.ones[i]
+      if zero_to_one:
+        print('id %s 0 -> 1 at byte %d bitmask %d' % (self.message_id, i, zero_to_one))
+      one_to_zero = other.ones[i] & self.zeros[i]
+      if one_to_zero:
+        print('id %s 1 -> 0 at byte %d bitmask %d' % (self.message_id, i, one_to_zero))
+
+
+class Info():
+  """A collection of Messages."""
+
+  def __init__(self):
+    self.messages = {}  # keyed by MessageID
+
+  def load(self, filename, start, end):
+    """Given a CSV file, adds information about message IDs and their values."""
+    with open(filename, newline='') as inp:
+      reader = csv.DictReader(inp)
+      dtype = None
+      for row in reader:
+        if not len(row):
+          continue
+        if dtype is None:
+          dtype = "logger" if "Bus" in row else "cabana"
+
+        time = float(row[CSV_KEYS[dtype]["time"]])
+        bus = int(row[CSV_KEYS[dtype]["bus"]])
+        if time < start or bus > 127:
+          continue
+        elif time > end:
+          break
+
+        message_id = row[CSV_KEYS[dtype]["message_id"]]
+        if message_id.startswith('0x'):
+          message_id = message_id[2:]  # remove leading '0x'
+        else:
+          message_id = hex(int(message_id))[2:]  # old message IDs are in decimal
+        message_id = f'{bus}:{message_id}'
+
+        data = row[CSV_KEYS[dtype]["data"]]
+        if data.startswith('0x'):
+          data = data[2:]  # remove leading '0x'
+        else:
+          data = data
+        new_message = False
+        if message_id not in self.messages:
+          self.messages[message_id] = Message(message_id)
+          new_message = True
+        message = self.messages[message_id]
+        bts = bytearray.fromhex(data)
+        for i in range(len(bts)):
+          ones = int(bts[i])
+          message.ones[i] = ones if new_message else message.ones[i] & ones
+          # Inverts the data and masks it to a byte to get the zeros as ones.
+          zeros = (~int(bts[i])) & 0xff
+          message.zeros[i] = zeros if new_message else message.zeros[i] & zeros
+
+def PrintUnique(log_file, low_range, high_range):
+  # find messages with bits that are always low
+  start, end = list(map(float, low_range.split('-')))
+  low = Info()
+  low.load(log_file, start, end)
+  # find messages with bits that are always high
+  start, end = list(map(float, high_range.split('-')))
+  high = Info()
+  high.load(log_file, start, end)
+  # print messages that go from low to high
+  found = False
+  for message_id in sorted(high.messages, key=lambda x: int(x.split(':')[1], 16)):
+    if message_id in low.messages:
+      high.messages[message_id].printBitDiff(low.messages[message_id])
+      found = True
+  if not found:
+    print('No messages that transition from always low to always high found!')
+
+if __name__ == "__main__":
+  if len(sys.argv) < 4:
+    print('Usage:\n%s log.csv <low-start>-<low-end> <high-start>-<high-end>' % sys.argv[0])
+    sys.exit(0)
+  PrintUnique(sys.argv[1], sys.argv[2], sys.argv[3])