py3-ecrterm/utils.py
2013-07-29 16:49:55 +02:00

45 lines
1.4 KiB
Python

# -*- coding: utf-8 -*-
#!/usr/bin/env python
"""
Utility Functions.
@author g4b
"""
from ecrterm.ecr import ECR
from ecrterm import packets
def detect_pt(device='/dev/ttyUSB0', timeout=2, silent=True,
ecr=None):
""" connects to given serial port and tests if a PT is present.
if present: tries to return version number or True
returns False otherwise.
@param timeout: set the timeout to have a faster response time.
@param silent: if False, exceptions won't be caught, default: True.
@param ecr: give a working ecr to perform this task. note: you have to
reconnect the transport since the timeout is changed.
"""
def __detect_pt(port, timeout, ecr):
e = ecr or ECR(port)
# reconnect to have lower timeout
e.transport.connect(timeout=timeout)
errors = e.transmit(packets.StatusEnquiry())
if not errors:
if isinstance(e.last.completion, packets.Completion):
return e.last.completion.fixed_values.get('sw-version', True) or True
return True
return False
if silent:
try:
return __detect_pt(device, timeout, ecr)
except:
return False
else:
return __detect_pt(device, timeout, ecr)
if __name__ == '__main__':
if detect_pt():
print "PT is online at ttyUSB0"
else:
print "PT cant be found at ttyUSB0"