Initial POC

door.py

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+import os, serial, socket, subprocess, select, datetime, sys
+import argparse
+
+parser = argparse.ArgumentParser()
+parser.add_argument("--serial_port", default="/dev/serial/by-id/usb-Imaginaerraum.de_DoorControl_43363220195053573A002C0-if01")
+parser.add_argument("--nfc_fifo", default="/tmp/nfc_fifo")
+parser.add_argument("--control_socket", default="/tmp/nfc.sock")
+parser.add_argument("--valid_tokens", default="/etc/door_tokens")
+parser.add_argument("--log_file", default="/tmp/nfc.log")
+parser.add_argument("--state_timeout", type=float, default=10)
+parser.add_argument("--repeat_time", type=float, default=5)
+
+config = parser.parse_args()
+
+# Log data to stdout and the log file
+def log(*args):
+    data = "%s %s" % (datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"), " ".join(i for i in args))
+    lgf.write(data + "\n")
+    lgf.flush()
+    print(data)
+
+# Opens the socket that can control the daemon
+# Commands are TBD
+def open_control_socket():
+    global control_socket
+    global config
+    global comm_channels
+
+    if os.path.exists(config.control_socket):
+        os.unlink(config.control_socket)
+
+    control_socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+    control_socket.bind(config.control_socket)
+    control_socket.listen(5)
+    comm_channels = []
+
+# Opens the serial port to talk to the lock actuator
+# Might return a failure. In that case, it will be tried again later
+def open_serial_port():
+    global serial_port
+    global config
+
+    try:
+        serial_port = serial.Serial(config.serial_port, timeout=2)
+    except:
+        serial_port = None
+        pass
+
+# Detected tokens are passed in through a FIFO
+def open_nfc_fifo():
+    global nfc_fifo
+    global config
+
+    nfc_fifo = open(config.nfc_fifo, "r")
+
+# Refresh valid tokens from the configured file
+def read_valid_tokens():
+    global valid
+    global config
+
+    try:
+        valid = [ s.strip() for s in open(config.valid_tokens, "r").readlines() ]
+    except:
+        valid = []
+        log("No valid tokens")
+
+# Opens the log file for writing
+def open_logfile():
+    global lgf
+    global config
+
+    lgf = open(config.log_file, "a+")
+
+# Actions
+IDLE, CLOSE, OPEN_THEN_CLOSE, OPEN, CLOSE_THEN_OPEN = range(5)
+# Current door state
+state = None
+# Current target action
+action = CLOSE
+# Start time of the current action
+start_time = datetime.datetime.now()
+# How often the action was repeated
+repeats = 0
+
+# Read the state of the door from the serial port
+def poll_door_state():
+    global state
+    global serial_port
+    serial_port.reset_input_buffer()
+    serial_port.write(b"R")
+    data = serial_port.readline().strip().split()
+    if data[0] == b'pos:':
+        data = int(data[1])
+        changed = False
+        if data < 80 and door_state != OPEN:
+            door_state = OPEN
+            changed = True
+        elif data > 100 and door_state != CLOSE:
+            door_state = CLOSE
+            changed = True
+        else:
+            print(data)
+    return door_state
+
+# Check the door state and send commands through a state machine
+def handle_door_state():
+    global action, target, serial_port, start_time, repeats
+    
+    state_names = {
+        OPEN: "open",
+        CLOSE: "close"
+        }
+    # Commands associated with each target state
+    target_state_cmd = {
+        OPEN:  b'O',
+        CLOSE: b'C'
+        }
+
+    old_state = state
+
+    # If no serial port, try to open it or return
+    if not serial_port:
+        try:
+            open_serial_port()
+        except:
+            return
+
+    # Get new state
+    poll_door_state()
+
+    # Idle + change = key?
+    if target == IDLE:
+        if state != old_state:
+            log("Door changed unexpectedly:", state_names[state])
+        return
+
+    # Target state, next action, timeout action
+    actions = {
+        OPEN:  (OPEN,  IDLE, CLOSE_THEN_OPEN ),
+        CLOSE: (CLOSE, IDLE, OPEN_THEN_CLOSE ),
+        OPEN_THEN_CLOSE: (OPEN, CLOSE, CLOSE ),
+        CLOSE_THEN_OPEN: (CLOSE, OPEN, OPEN  )
+    }
+
+    # Target state reached
+    if state == actions[action][0]:
+        # Select next action, reset start time and repetitions
+        action = actions[action][1]
+        start_time = datetime.datetime.now()
+        repeats = 0
+        # On idle, we're done
+        if action == IDLE:
+            log("Reached target position:", state_names[state])
+            return
+
+    # Execution time
+    t = (datetime.datetime.now() - start_time)
+    if t >= config.state_timeout:
+        # Timeout -> switch to timeout action
+        action = actions[action][2]
+        start_time = datetime.datetime.now()
+        repeats = 0
+        log("Timeout. Switching to", action)
+    elif t >= (1 + repeats) * config.repeat_time:
+        # Repeat every couple of seconds
+        repeats += 1
+        serial_port.write(target_state_cmd[actions[action][0]])
+        log("Repeating command:", target_state_cmd[actions[action][0]])
+
+def open_door():
+    global action
+    log("Opening the door")
+    action = OPEN
+
+def close_door():
+    global action
+    log("Closing the door")
+    action = CLOSE
+
+def toggle_door_state():
+    global state, action
+    if state == CLOSE:
+        open_door()
+    else:
+        close_door()
+
+def handle_nfc_token():
+    global valid
+    
+    token = nfc_fifo.readline()
+
+    if token == "":
+        open_nfc_fifo()
+
+    token = token.strip()
+    if token in valid:
+        log("Valid token:", token)
+        toggle_door_state()
+    else:
+        log("Invalid token:", token)
+
+open_logfile()
+read_valid_tokens()
+open_nfc_fifo()
+open_serial_port()
+open_control_socket()
+
+while True:
+    readable = select.select([ nfc_fifo, control_socket ] + comm_channels, [], [], 0.5)[0]
+
+    for c in readable:
+        if c == nfc_fifo:
+            handle_nfc_token()
+        elif c == control_socket:
+            comm_channels.append(control_socket.accept()[0])
+        else:
+            data = c.recv(1024)
+            if len(data) == 0:
+                comm_channels.remove(c)
+            else:
+                print("Got comms data: ", str(c.recv(1024)))
+                c.sendall(b':)\n')