Hi Doug, Have you looked at the struct module which provides tools for encoding binary values into byte streams and decoding byte streams into binary data.
However if you only need to inject some hex codes into a string you can use the chr() function, this works even for unprintable characters like control sequences. HTH, Alan G Author of the learn to program web tutor http://www.freenetpages.co.uk/hp/alan.gauld ----- Original Message ----- From: "doug shawhan" <[EMAIL PROTECTED]> To: <tutor@python.org> Sent: Monday, April 17, 2006 10:40 PM Subject: [Tutor] Raw Bits! (Control characters ahoy!) I am in the middle of a project that requires me to send and retrieve information from a machine connected to a serial port. My problems are these: 1. I cannot send control characters 2. I cannot read data streaming from the serial port I have been doing fine with: os.system("echo '5' >/dev/tty00") os.system("echo '8' >/dev/tty00") and the like to the remote machine, but I need to be able to send control characters the same way to scroll through menus. I have tried pyserial and pexpect with mixed (mostly horrible) results (not the fault of the module builders!), thus far the simple act of echoing the strings to the serial port is the only reliable method I have found. Reading from the serial port has also been problematic. I find that simply opening the port /dev/tty00 file and using readlines(), read() or whatever gives me empty strings or lists. Pbth. So first: how should I go about adding the hex escape sequences (\x0a and \x50) to the above strings in their raw form? second: what method should I use to read a raw stream from the serial port for a given period? I have looked carefully at the neat and tidy miniterm.py example in the pyserial examples directory, and see how one can continuously read via a thread from the port, but have not been able to replicate it thus far. Any help whatsoever would be great! I'm beginning to feel a little lightheaded. Thanks! _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
