amikhalev/uas-ugv
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use base64 encoding in python script

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This commit is contained in:
Alex Mikhalev 2019-05-09 10:22:04 -07:00
parent d07517b2e9
commit 771b98a667
1 changed files with 19 additions and 16 deletions
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35
e32_client/ugv.py
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@ -5,6 +5,8 @@ import serial
import threading
from threading import Thread
import time
import binascii
from base64 import b64decode, b64encode
from e32 import E32
import messages_pb2 as messages
@ -12,8 +14,8 @@ from google.protobuf.message import Message
class UGVComms(E32):
MAX_WRITE_RETRY=5
RETRY_TIME=1.0
MAX_WRITE_RETRY = 5
RETRY_TIME = 1.0
def __init__(self, serial_port: serial.Serial):
E32.__init__(self, serial_port)
@ -23,16 +25,15 @@ class UGVComms(E32):
self.last_status = None
self.rx_thread = None
def write_len_delimited(self, data: bytes):
len_data = (len(data)).to_bytes(
1, byteorder='big') # TODO: check byte order
self.ser.write(len_data)
self.ser.write(data)
def write_base64(self, data: bytes):
encoded = b64encode(data)
self.ser.write(encoded)
self.ser.write(b'\n')
def write_message(self, msg: Message):
print("writing message: ", msg)
data = msg.SerializeToString()
self.write_len_delimited(data)
self.write_base64(data)
def write_command(self, cmd_type: messages.GroundCommandType, retry=True):
cmdid = self.next_command_id
@ -59,17 +60,17 @@ class UGVComms(E32):
self.ack_cv.wait(timeout=time_left)
def read_message(self):
len_data = self.ser.read(size=1)
if len(len_data) != 1:
data = self.ser.read_until(terminator=b'\n')
if len(data) is 0:
return None
msg_len = int.from_bytes(len_data, byteorder='big')
data = self.ser.read(size=msg_len)
if len(data) != msg_len:
try:
decoded = b64decode(data, validate=True)
except binascii.Error:
print("read bad data: ", data)
self.ser.flush()
return None
msg = messages.UGV_Message()
msg.ParseFromString(data)
msg.ParseFromString(decoded)
return msg
def process_message(self, msg: messages.UGV_Message):
@ -82,7 +83,7 @@ class UGVComms(E32):
self.ack_cv.notify()
elif msg.HasField("status"):
self.last_status = msg.status
def start(self):
self.rx_thread = Thread(target=self.__rx_thread_entry, daemon=True)
self.rx_thread.start()
@ -102,6 +103,7 @@ class UGVComms(E32):
print("error reading message: ", e, file=sys.stderr)
continue
def main():
if len(sys.argv) >= 2:
ser_url = sys.argv[1]
@ -109,7 +111,7 @@ def main():
ser_url = "hwgrep://"
ser = serial.serial_for_url(ser_url, baudrate=9600, parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE, bytesize=serial.EIGHTBITS,
timeout=1.0)
timeout=0.5)
ugv = UGVComms(ser)
ugv.start()
time.sleep(0.2)
@ -126,5 +128,6 @@ def main():
ugv.ser.close()
ugv.stop()
if __name__ == "__main__":
main()