def base_st_connect(self):
"""
Sends a confirmation message to Base Station to acknowledge connection. If it receives and ACK from Base Station, starts up the Sensor_thread.
"""
self.tried = 0
while(self.tried<=5):
LOGMSG("Checking if base station is responding...")
self.tried += 1
msg = pack('8sBBB','SLIPCC11',kelvin.DISPATCH,kelvin.CMD | kelvin.CONN_REQ, 0)
self.write(msg)
time.sleep(2)
rsp = self.read()
if(rsp != b''):
break
if(self.tried > 5):
LOGMSG("Base station currently unreachable. Please try later.")
LOGMSG("The server will now close...")
self.close()
else:
LOGMSG("Connected to base station.")
#Start a thread which will handle all sensor data extraction
self.sensor = Sensor(self)
self.sensor.start()
class Serial_conn:
"""
Serial communication class. Provides connection and message transmission functionalities.
"""
def __init__(self):
"""
Initializes the SComms module.
"""
self.supports_base64 = False
LOGMSG ("Server starting")
self.start()
def get_port(self):
"""
Specified the port number to be opened. Scans all available ports, and prompts the user to select a port number to be opened
@rtype: number
@return: the port number to be opened
"""
ports = self.scan_for_ports()
while(ports == []):
LOGMSG("Base station is not connected to any serial port. Please connect base station before proceeding. Press ENTER to try again, or type EXIT to quit")
msg = input()
if(msg==''):
ports = self.scan_for_ports()
elif(msg=='exit'):
exit()
elif(msg=='break'):
break
else:
LOGMSG('Invalid command!Please try again')
msg = "Serial connections detected at the following ports:"
i = 0
while(i<len(ports)):
msg += " COMM%d" %ports[i]
i += 1
LOGMSG(msg)
self.port = int(input("Please select a PORT number: "))
while((self.port<1) | (self.port>10)):
self.port = int(input("Invalid PORT number! Please enter a valid PORT number: "))
return self.port
def get_baud(self, msg="Please enter the baudrate of the connection, or press ENTER to skip this step (the baudrate will be set to default value 38400): "):
"""
Prompts the user for a baudrate value. If none selected, a default value is chosen.
@type msg: string
@param msg: the prompt message to be displayed to the user.
@rtype: number
@return: the baudrate value
"""
self.baud = (input(msg))
if(self.baud==''):
self.baud = 38400
return int(self.baud)
def get_timeout(self, msg="Please enter the connection timeout (in seconds), or press ENTER to skip this step (the timeout will be set to default value 1): "):
"""
Prompts the user for a timeout value. If none selected, a default value is chosen.
@type msg: string
@param msg: the prompt message to be displayed to the user.
@rtype: number
@return: the timeout value
"""
self._timeout = (input(msg))
if(self._timeout==''):
self._timeout = 1
return int(self._timeout)
def close(self,status=0):
"""
Terminates the serial communication and closes the the sensor_thread instance
@type status: number
@param status: the close status value
"""
try:
self.sensor.close()
except:
if(self.serial != None and self.serial.isOpen()):
self.serial.close()
def start(self):
"""
Starts the SComms module. Prompts the user for a port number, baudrate and timeout values, and connects to the Base Station using these values.
"""
self.port = self.get_port()
self.baud = self.get_baud()
self._timeout = self.get_timeout()
# Establish serial port connection
self.connect(self.port-1, self.baud, self._timeout)
# Connect to base station
self.base_st_connect()
def base_st_connect(self):
"""
Sends a confirmation message to Base Station to acknowledge connection. If it receives and ACK from Base Station, starts up the Sensor_thread.
"""
self.tried = 0
while(self.tried<=5):
LOGMSG("Checking if base station is responding...")
self.tried += 1
msg = pack('8sBBB','SLIPCC11',kelvin.DISPATCH,kelvin.CMD | kelvin.CONN_REQ, 0)
self.write(msg)
time.sleep(2)
rsp = self.read()
if(rsp != b''):
break
if(self.tried > 5):
LOGMSG("Base station currently unreachable. Please try later.")
LOGMSG("The server will now close...")
self.close()
else:
LOGMSG("Connected to base station.")
#Start a thread which will handle all sensor data extraction
self.sensor = Sensor(self)
self.sensor.start()
def connect(self, port , baud = 38400 , _timeout = 1):
"""
Tries to connected to specified port, using given baudrate and timeout values
@type port: number
@param port: the port to be opened
@type baud: number
@param baud: the specified baudrate
@type _timeout: number
@param _timeout: the specified timeout value
"""
LOGMSG("Connecting to base station ...")
try:
self.serial = Serial(port,baud, timeout = _timeout)
except serialutil.SerialException:
LOGMSG ("Could not open port %d." %self.port)
LOGMSG ("Retrying to reconnect in 5 seconds..." )
time.sleep(5)
LOGMSG("Reconnecting...")
try:
self.serial = Serial(port,baud, timeout = _timeout)
except serialutil.SerialException:
LOGMSG("Could not open port %d." %self.port)
self.port = self.get_port("Maybe the PORT number is wrong? Please enter PORT number again: ");
LOGMSG("Reconnecting...")
try:
self.serial = Serial(port,baud, timeout= _timeout)
except serialutil.SerialException:
LOGMSG ("Could not open port %d. " %self.port)
LOGMSG("Please check you configurations and PORT connections!")
self.close(1)
LOGMSG("Serial connection established on port %d. Using baudrate %d and timeout %d" %(self.port, self.baud, self._timeout))
def scan_for_ports(self):
"""
Scans the system for open ports
@rtype: array
@return: an array of available ports
"""
result=[]
ports = scan()
if (len(ports) >0):
i = 1
while(i<len(ports)):
result.append(ports[i][0]+1)
i+=1
return result
################################################## Serial functions ############################################
def _process_line(self, line):
"""
Process line and return.
- Checks if the other end responds in Base64 and changes operating mode.
- Removes trailing \r\n
"""
if line is not None and len(line) > 0:
line = line.rstrip(b'\r\n')
if line[:1] == b'!':
self.supports_base64 = True
try:
line = b''.join([b64decode(part) for part in line.split(b'!')[1:]])
except:
DEBUG("Could not decode!")
return line
def read( self ):
"""
Calls _process_line to read incoming messages
"""
return self._process_line(self.serial.readline())
def write( self, string ):
"""
Only responds in Base64 if a previously received line was Base64.
Adds \r\n
"""
if self.supports_base64:
string = b'!' + b64encode(string)
self.serial.write( string + b'\r\n' )
def __iter__(self):
self._current_iter = iter(self.serial)
return self
def __next__(self):
return self._process_line(self._current_iter.__next__())
def set_color(self, col):
self.writeline(b"s "+str(col))
def flash(self):
i = 0
for i in range(100):
self.set_color(randint(0,7))
time.sleep(randint(1,7)/20)
################################### DEPRECATED ############################################
def pause(self):
"""
Pauses the sensor_thread
- Deprecated
"""
if(self.sensor != None):
if(self.sensor.closed != 1):
if(self.sensor.paused != 1):
self.sensor.paused = 1
DEBUG("Flow paused")
else:
DEBUG("Already paused!")
def resume(self):
"""
Resumes the sensor_thread
- Deprecated
"""
if(self.sensor != None):
if(self.sensor.closed != 1):
if(self.sensor.paused == 1):
self.sensor.paused = 0
DEBUG("Flow resumed")
else:
DEBUG("Flow not paused!")
