initial version

.gitignore

@@ -0,0 +1,4 @@
+__pycache__
+.vscode
+openhab/heatpump-pow.items
+openhab/heatpump-pow.rules

Makefile

@@ -0,0 +1,6 @@
+deploy:
+	scp *.py 192.168.3.4:/opt/zehnder-can-mqtt
+ohitems:
+	cd openhab && python3 items.py > comofair.items
+
+.PHONY: deploy ohitems

USBCAN.py

@@ -0,0 +1,150 @@
+import serial
+from time import sleep
+import logging
+import sys
+
+logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
+logger = logging.getLogger('comfoair-can')
+
+class CN1FAddr:
+  def __init__(self, SrcAddr, DstAddr, Address, MultiMsg, A8000, A10000, SeqNr):
+    self.SrcAddr = SrcAddr
+    self.DstAddr = DstAddr
+    self.Address = Address
+    self.MultiMsg = MultiMsg
+    self.A8000 = A8000
+    self.A10000 = A10000
+    self.SeqNr = SeqNr
+
+  def id(self):
+    addr = 0x0
+    addr |= self.SrcAddr << 0
+    addr |= self.DstAddr << 6
+
+    addr |= self.Address <<12
+    addr |= self.MultiMsg<<14
+    addr |= self.A8000   <<15
+    addr |= self.A10000  <<16
+    addr |= self.SeqNr   <<17
+    addr |= 0x1F         <<24
+
+    return addr
+  def hex(self):
+    return hex(self.id())[2:]
+
+  def bytes(self):
+    return bytes.fromhex(self.hex())
+
+class CANInterface:
+
+  START_BYTE_1 = 0x55
+  START_BYTE_2 = 0XAA
+
+  COMFOAIR_ADDRESS = 1
+
+  send_sequence_nr = 0
+
+  def __init__(self, device, baudrate):
+    self.device = device
+    self.baudrate = baudrate
+
+  def open(self):
+    self.sp = serial.Serial(self.device, self.baudrate)  
+    self._send_magic_init_packet()
+
+  def read(self, callback):
+    frame = bytearray()
+    while True:
+      if self.sp.in_waiting != 0:
+        new_byte = self._get_single_byte()
+        if new_byte == self.START_BYTE_1:
+          next_byte = self._get_single_byte()
+          if next_byte == self.START_BYTE_2:
+              id = frame[1:5]
+              data =frame[5:]
+              id_hex = str() + format(int.from_bytes(id, byteorder='little'), '#10X')
+              pdid = (int(id_hex, 16)>>14)&0x7ff
+              frame = bytearray()
+              callback(pdid, data)
+          else:
+              frame.append(new_byte)
+              frame.append(next_byte)
+        else:
+          frame.append(new_byte)
+      else:
+        sleep(1)
+
+  def send(self, data):
+    num_bytes = len(data)
+    can_id = CN1FAddr(0x11, self.COMFOAIR_ADDRESS, 1, num_bytes>8, 0, 1, self.send_sequence_nr)
+    self.send_sequence_nr = (self.send_sequence_nr + 1)&0x3
+    if len(data) > 8:
+      datagrams = int(len(data)/7)
+      if len(data) == datagrams*7:
+          datagrams -= 1
+      for n in range(datagrams):
+          self._write_to_can(can_id.bytes(), [n]+data[n*7:n*7+7])
+      n+=1
+      restlen = len(data)-n*7
+      self._write_to_can(can_id.bytes(), [n|0x80]+data[n*7:n*7+restlen])
+    else:
+      self._write_to_can(can_id.bytes(), data)
+
+  #----- private
+  def _get_single_byte(self):
+    return int.from_bytes(self.sp.read(size=1),  byteorder='little')
+
+
+  def _write_to_can(self, id, data):
+    num_bytes=len(data)
+    send_buf = bytearray([0xAA,0xE0|num_bytes,])
+    for byte in reversed(id):
+        send_buf.append(byte)
+    for byte in data:
+        send_buf.append(byte)
+    send_buf.append(0x55)
+    self.sp.write(send_buf)
+
+
+  def _send_magic_init_packet(self):
+    send_buf = bytearray()
+    send_buf.append(0xAA)
+    send_buf.append(0x55)
+    #Pack mystery byte
+    send_buf.append(0x12)
+    #Pack byte indicating CAN bus speed
+    send_buf.append(0x09)
+    #Pack frame type byte
+    #use extended
+    send_buf.append(0x02)
+    #Filter not supported
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    #Mask not supported
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    #Hardcode mode to Normal? Set to 0x01 to get loopback mode
+    send_buf.append(0x00)
+    #Send magic byte (may have to be 0x01?)
+    send_buf.append(0x01)
+    #Send more magic bytes
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+    send_buf.append(0x00)
+
+    #Calculate checksum
+    checksum = 0
+    for idx in range(0,18):
+        checksum += int(send_buf[idx])
+    checksum = checksum % 255
+
+    send_buf.append(checksum)
+    self.sp.write(send_buf)
+    logger.info('init config done')
+
+

main.py

@@ -0,0 +1,52 @@
+import paho.mqtt.client as mqtt
+import logging
+import sys
+
+from USBCAN import CANInterface
+import mapping
+from time import sleep
+
+def on_mqtt_connect(client, userdata, flags, rc):
+  logger.info('ubscribing to comfoair/action')
+  client.subscribe('comfoair/action')
+
+def on_mqtt_message(client, userdata, msg):
+  action =str(msg.payload.decode('utf-8'))
+  logger.info('got mqtt message %s %s', msg.topic, action)
+  if action in mapping.commands:
+    command = mapping.commands[action]
+    logger.info('action ok, executing: %s', action)
+    try:
+      for i in range(3):
+        can.send(command)
+        sleep(2)
+    except Exception as e:
+      logger.error('failed in send %s', e)
+  else:
+    logger.error('action not found %s', action)
+
+def process_can_message(pdid, data):
+  if pdid in mapping.data:
+    pdid_config = mapping.data[pdid]
+    value =  pdid_config.get('transformation')(data)
+    if pdid_config.get('ok'):
+      name = pdid_config.get('name')
+      mqtt_client.publish('comfoair/status/' + name, value)
+    else:
+      logger.info('not ok, not pushing %s %s', pdid, value)
+  elif pdid != 0:
+    logger.info('pid not found %s %s', pdid, data)
+
+logger = logging.getLogger('comfoair-main')
+logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
+
+logger.info('starting up')
+mqtt_client = mqtt.Client()
+mqtt_client.connect('192.168.3.4', 1883, 60)
+mqtt_client.on_connect = on_mqtt_connect
+mqtt_client.on_message = on_mqtt_message
+mqtt_client.loop_start()
+
+can = CANInterface('/dev/ttyUSB0', 2000000)
+can.open()
+can.read(process_can_message)