from __future__ import absolute_import
import logging
import serial
import collections
import serial.tools.list_ports as list_ports
from . import Exceptions
class Uart:
def __init__(self, portnum=None, useByteQueue=False):
self.ser = None
try:
self.ser = serial.Serial(
port=portnum,
baudrate=460800,
bytesize=serial.EIGHTBITS,
parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE,
timeout=None, # seconds
writeTimeout=None,
rtscts=True
)
except Exception as e:
if self.ser:
self.ser.close()
raise
self.useByteQueue = useByteQueue
self.byteQueue = collections.deque()
# if self.ser.name != None:
# print "UART %s on port %s" % ("open" if self.ser else "closed", self.ser.name)
def __del__(self):
if self.ser:
logging.info("closing UART")
self.ser.close()
def switchBaudRate(self, newBaudRate):
self.ser.baudrate = newBaudRate
def read(self, length, timeout=None):
if timeout != self.ser.timeout:
try:
self.ser.timeout = timeout
except ValueError as e:
logging.error("Error setting UART read timeout. Continuing.")
value = self.ser.read(length)
if len(value) != length:
raise Exceptions.SnifferTimeout(
"UART read timeout (" + str(self.ser.timeout) + " seconds).")
if self.useByteQueue:
self.byteQueue.extend(value)
return value
def readByte(self, timeout=None):
readString = ""
readString = self.read(1, timeout)
return readString
def readList(self, size, timeout=None):
return self.read(size, timeout)
def writeList(self, array, timeout=None):
nBytes = 0
if timeout != self.ser.writeTimeout:
try:
self.ser.writeTimeout = timeout
except ValueError as e:
logging.error("Error setting UART write timeout. Continuing.")
try:
nBytes = self.ser.write(array)
except: # noqa: E722
self.ser.close()
raise
return nBytes
def list_serial_ports():
# Scan for available ports.
return list_ports.comports()
