Serial Communication from shell Mac OS X PHP script. Has anyone had any luck with serial port communication from any other shell scripting language on a unix/linux. PHP Serial I somehow got hold of a « Citizen C2202-PD » point-of-sale display, and I wanted to play around with it. I also managed to get the documentation of it, and created a convenience class to access the serial port though the Linux file.

I am doing some embedded systems development work and I have an FTDI USB to Serial bridge chip on the board I am working on. Hp Laserjet P2014 Driver Software on this page. It randomly drops received bytes. This only happens under Arch linux as I just recently switched from Ubuntu and I had no problems there. I have the same problem on another computer I use that also runs Arch, though the problem there is much worse. I'm assuming it's a kernel interrupt priority issue. I don't really know where to start debugging this, so any input would be much appreciated.

Unfortunately, it's quite random. Sometimes it's rock solid and sometimes it drops a byte every few hundred or so, causing some rather anoying issues. Cast in point: it seems to be working fine at the moment but earlier it was wreaking havoc while I was tring to carry out some calibration operations. The other computer I tried it with is consistently bad, though, getting out of sync almost immediately. The first computer (usually good performance) has a high end 2nd gen core i7 (sandy bridge) while the second (not so good performance) computer has an intel atom processor. Last edited by alex.forencich (2011-09-01 07:07:02).

I did some testing on my eee pc (same one as the previous post with an atom processor). Hp 5940 Windows 7 Driver there. In Ubuntu, the connection is rock solid.

Didn't drop a single byte in 10 minutes of heavy data transfer. However, in Arch, it consistently drops at least one byte within 2 minutes and breaks the synchronization between the desktop application and the board. Now, I am going to add checks to reset the connection if it comes out of sync, but I really want to figure out what the underlying cause is here since it's definitely not a problem with the USB-serial chip or my firmware. The device on the other end is an Atmel xmega microcontroller. I did not use any flow control when I wrote the firmware as the communication routines in the firmware are very fast as the chip runs at 32 MHz and the USART is interrupt driven. Since only one byte at a time gets dropped, the chip is definitely receiving and responding to the bytes sent as most of the commands are 3 bytes and the responses are 3 bytes, so more than one byte would get lost if a byte got lost on the way there. Championship Swim Training Bill Sweetenham Pdf Printer.