En Tue, 09 Mar 2010 12:01:22 -0300, kishore <kishorei...@gmail.com>
escribió:
> Iam using python 2.5.4
> pyserial 2.4
> pywin32-214
> on windows 7
> i hav a small test script written to query a serial device (arduino)
> and get back reply appropriately
Thanks for your response
i tried closing idle and the following code prints
port opened
Write failed
code:
import serial
import time
ser=serial.Serial(port='\\.\COM2', baudrate=9600)
If you want a string containing these 8 characters \\.\COM2 you have to
write it either as r'\\.\COM2' or '\\\\.\\COM2'
if ser:
print 'port opened'
Either the Serial object is constructed and returned, or an exception is
raised. 'if ser:' has no sense; Python is not C...
ser.open()
if ser.write('1'):
print 'Write success'
else:
print 'write failed'
The write method, when successful, implicitly returns None. None has a
false boolean value, so your code will always print 'write failed'.
Usually, in Python, error conditions are marked by raising an exception.
Using return values to indicate success/failure is uncommon.
Also, are you sure the device doesn't expect a newline character? '1\n'?
You may need to call ser.flushOutput() to ensure the output buffer is
actually emptied.
time.sleep(1)
a=ser.readline()
print repr(a)
time.sleep(1)
b=ser.readline()
print repr(b)
ser.close()
I believe this might be a serial port access error.
how to solve this?
Any suggestions?
I don't think so. If you could not access the serial port, you'd have seen
an IOError exception or similar.
--
Gabriel Genellina
--
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