def __init__(self, port="/dev/ttyUSB0", baud=9600):
"""constructor"""
#indicates whether there is a connection on the selected port
self.enabled = False
#create a connection on the selected port
self.initialize_connection(port, baud)
#try to open on ttyUSB1 if ttyUSB0 fails
if self.enabled == False:
self.initialize_connection("/dev/ttyUSB1", baud)
#talker identifier = IS (ImageStation)
self.identifier = "IS"
#set encoder and decoder
self.encoder = NmeaEncoder(self.identifier)
self.decoder = NmeaDecoder()
class SerialInterface(Interface):
"""interface class to use when there is no connection selected."""
def __init__(self, port="/dev/ttyUSB0", baud=9600):
"""constructor"""
#indicates whether there is a connection on the selected port
self.enabled = False
#create a connection on the selected port
self.initialize_connection(port, baud)
#try to open on ttyUSB1 if ttyUSB0 fails
if self.enabled == False:
self.initialize_connection("/dev/ttyUSB1", baud)
#talker identifier = IS (ImageStation)
self.identifier = "IS"
#set encoder and decoder
self.encoder = NmeaEncoder(self.identifier)
self.decoder = NmeaDecoder()
# FOR REFERENCE: Dictionary of sentence identifiers
#
# "toggle_power" : "CPW"
# "set_mode" : CMO"
# "take_picture" : "CPT"
# "toggle_record: "CRC"
# "pan" : "CPA"
# "tilt" : "CTI"
# "resume_search" : ""
# "lock_target" : "",
# "acknowledge download_to_flc" : "FLC"
# "download to FLC complete" : "FLD"
# "generate_crop" : "CRP"
# "request_info" : "INF"
# "request_size" : "PSZ"
# "download_segment" : "DPC"
# "ping" : "PNG"
#*
#* Define Abstract functions
#*
def toggle_power(self):
"""toggle power on and off for the camera"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CPW")
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def set_mode(self, mode):
"""set the mode for the camera (0 for storage, 1 for camera mode)"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CMO", mode)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def take_picture(self, picture_num):
"""snap a picture."""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CPT", picture_num)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def toggle_record(self):
"""toggle recording on and off for the camera"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CRC")
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def pan(self, value):
"""set the pan servo to position (-180 to 180)"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CPA", value)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def tilt(self, value):
"""set the pan servo to position (-45 to 45)"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CTI", value)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
#def resume_search(self):
# """have the camera resume it's search pattern."""
# if self.enabled == True:
# try:
# msg_to_send = self.encoder.encode("")
# return self.tx_rx_decode(msg_to_send)
# except InterfaceError as e:
# raise InterfaceError(e.value)
# else:
# raise InterfaceError("no serial connection")
#def lock_target(self, xa, ya):
# """lock onto a target given pixels xa and ya."""
# if self.enabled == True:
# try:
# msg_to_send = self.encoder.encode("", xa, ya)
# return self.tx_rx_decode(msg_to_send)
# except InterfaceError as e:
# raise InterfaceError(e.value)
# else:
# raise InterfaceError("no serial connection")
def download_to_flc(self):
"""download pictures form the camera memory onto the
flight linux computer."""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("FLC")
self.tx_rx_decode(msg_to_send)
return self.rx_decode()
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def generate_crop(self, picture_num, xa, ya, xb, yb):
"""generate a crop of an image given the image number,
xa, ya, xb, and yb. which represent the top left and bottom right
corners of a rectangle."""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("CRP", picture_num, \
xa, ya, xb, yb)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def request_info(self, picture_num):
"""get all positional info about a picture
returns gps_x, gps_y, pan, tilt, yaw, pitch, roll, orientation, altitude"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("INF", picture_num)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def request_size(self, picture_num, crop_num):
"""get the size of a crop"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("PSZ", picture_num, crop_num)
return self.tx_rx_decode(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
def download_segment(self, picture_num, crop_num, segment_num):
"""download a segment of an image"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("DPC", picture_num, \
crop_num, segment_num)
return self.tx_rx_decode_bin(msg_to_send)
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
#def camera_zoom_in(self, increment):
# """have the camera zoom in."""
# if self.enabled == True:
# try:
# msg_to_send = self.encoder.encode("CZI", increment)
# return self.tx_rx_decode(msg_to_send)
# except InterfaceError as e:
# raise InterfaceError(e.value)
# else:
# raise InterfaceError("no serial connection")
#def camera_zoom_out(self, increment):
# """have the camera zoom out."""
# if self.enabled == True:
# try:
# msg_to_send = self.encoder.encode("CZO", increment)
# return self.tx_rx_decode(msg_to_send)
# except InterfaceError as e:
# raise InterfaceError(e.value)
# else:
# raise InterfaceError("no serial connection")
def ping(self):
"""ping the plane"""
if self.enabled == True:
try:
msg_to_send = self.encoder.encode("PNG")
t1 = time.time()
self.tx_rx_decode(msg_to_send)
t2 = time.time()
return (t2-t1)*1000.0
except InterfaceError as e:
raise InterfaceError(e.value)
else:
raise InterfaceError("no serial connection")
#*
#* Non-Abstract functions
#*
def initialize_connection(self, port, baud):
"""try to create a connection on the specified serial port."""
try:
self.ser = serial.Serial(port)
self.ser.baudrate = baud
self.ser.bytesize = 8
self.ser.stopbits = 1
self.ser.rtscts = 1
self.ser.timeout = 1
self.enabled = True
print "serial connection successful on port %s at %d baud" % (port, baud,)
except serial.serialutil.SerialException as e:
self.enabled = False
print "serial connection failed on port %s" % (port,)
print e
def tx_rx_decode(self, msg_to_send):
"""transmit to the plane, recieve a response, and decode it."""
attempts = 0
while (attempts < 3):
self.ser.write(msg_to_send)
### DEBUGGING ###
print "sending msg: %s" % (msg_to_send,)
### /DEBUGGING ###
response = self.ser.readline()
if response:
### DEBUGGING ###
print "received msg: %s" % (response,)
### /DEBUGGING ###
try:
### DEBUGGING ###
print "returned args array: %s" % (self.decoder.decode(response),)
### /DEBUGGING ###
return self.decoder.decode(response)
except DecodeError as e:
attempts += 1
error_msg = e.value
#flush the serial line
else: #timeout
attempts += 1
error_msg = "waiting for response timed out"
#flush the serial line
# attempts > 3, failure
raise InterfaceError(error_msg)
def tx_rx_decode_bin(self, msg_to_send):
"""transmit to the plane, recieve a response, and decode it.
This should be used when decoding responses with binary arguments,
in this case a random /r/n could appear, so a different decoding
method must be used"""
attempts = 0
while (attempts < 3):
length = 0
# get and decode the message containing the length
self.ser.write(msg_to_send)
### DEBUGGING ###
print "sending msg: %s" % (msg_to_send,)
### /DEBUGGING ###
response1 = self.ser.readline()
if response1:
### DEBUGGING ###
print "received msg1: %s" % (response1,)
### /DEBUGGING ###
try:
### DEBUGGING ###
print "returned args array: %s" % (self.decoder.decode(response1),)
### /DEBUGGING ###
(length_str,) = self.decoder.decode(response1)
length = int(length_str)
except DecodeError as e:
attempts += 1
error_msg = e.value
#flush the serial line
else: #timeout
attempts += 1
error_msg = "waiting for response timed out"
#flush the serial line
# get and decode the message containing image data
response2 = self.ser.read(length)
if response2:
### DEBUGGING ###
print "received msg2: %s" % (response2,)
### /DEBUGGING ###
try:
### DEBUGGING ###
print "returned args array: %s" % (repr(self.decoder.decode_bin(response2)),)
### /DEBUGGING ###
return self.decoder.decode_bin(response2)
except DecodeError as e:
attempts += 1
error_msg = e.value
#flush the serial line
else: #timeout
attempts += 1
error_msg = "waiting for response timed out"
#flush the serial line
# attempts > 3, failure
raise InterfaceError(error_msg)
def rx_decode(self):
"""recieve a response and decode it."""
print "in rx_decode"
attempts = 0
MAX_ATTEMPTS = 999
while (attempts < MAX_ATTEMPTS):
response = self.ser.readline()
if response:
### DEBUGGING ###
print "received msg: %s" % (response,)
### /DEBUGGING ###
try:
### DEBUGGING ###
print "returned args array: %s" % (self.decoder.decode(response),)
### /DEBUGGING ###
return self.decoder.decode(response)
except DecodeError as e:
attempts += 1
error_msg = e.value
#flush the serial line
else: #timeout
attempts += 1
error_msg = "waiting for response timed out"
#flush the serial line
# attempts > 3, failure
raise InterfaceError(error_msg)
############################################################################### # # file: testencoder.py # author: Cogan Noll # email: [email protected] # last modified: 2010 # ############################################################################### from NmeaEncoder import * from NmeaDecoder import * from Interface import * encoder = NmeaEncoder("IS") decoder = NmeaDecoder() def tx_rx_decode(func_name, msg_to_send): """transmit to the plane, recieve a response, and decode it.""" attempts = 0 while (attempts < 3): response = "$PVCPT,arg1,arg2,1160\r\n" # might put this in to work with my decoder # response += "\n" if response: try: return decoder.decode(response) except DecodeError as e: attempts += 1 error_msg = e.value else: #timeout attempts += 1
