#!/usr/bin/python -u
"""
test serial loopback; assumes Rx and Tx are connected
Copyright (c) 2010-2014 Ben Bass <benbass@codedstructure.net>
All rights reserved.
"""
import os
import sys
import time
from pylibftdi import Device
# TODO:
# make this threaded - a writer stream, which sends known data with
# occasional sync blocks, and a reader which reads and waits for a sync-block
# then signals the writer if it gets stuck.
[docs]def test_string(length):
return os.urandom(length)
[docs]class LoopbackTester(object):
[docs] def __init__(self):
self.device = Device()
[docs] def test_loopback(self, lengths):
self.device.flush()
time.sleep(0.1)
for l in lengths:
test_str = test_string(l)
if self.device.write(test_str) != len(test_str):
sys.stdout.write('*')
time.sleep(0.1)
result = ''
for _ in range(3):
result = self.device.read(l)
if result:
break
if result != test_str:
self.device.flush()
time.sleep(0.25)
yield result == test_str
[docs] def main(self):
for bd in [9600, 31250, 115200, 1152000]:
self.device.baudrate = bd
for result in self.test_loopback(range(1, 50) + range(100, 500, 100) +
range(1000, 5000, 1000)):
if result:
sys.stdout.write('+')
else:
sys.stdout.write('!')
sys.stdout.write('\n')
if __name__ == '__main__':
tester = LoopbackTester()
tester.main()