Php Serial Port Communication Linux Vs Windows
(9 replies) Hi there I´ve got a problem porting from windows to Linux, when I wanna read and write to the serial port. This works like a charm in windows: if (!$fp.
Core question: How does UART connection on *nix differ from UART connection on Windows? What settings need to be kept in consideration for proper data transmission and reception? Context for asking this question: This question is related to my other one on site. Basically, I've a serial (USB to RS-232) connection with my Ubuntu laptop to microcontroller, and I receive last 4 bits correctly, but not first 4. On Windows I receive all 8 bits.
What could be the possible issue? More importantly, I am interested in the difference of Windows UART vs Linux UART Specifics: The main on the microcontroller I am using ( PIC 18F87J11 ) has very simple code: while (1) { while (!PIR1bits.RC1IF); //Wait for a byte sprintf(txStr,'%.5X',RCREG); LCDWriteLine(txStr,0); The point here is that it receives a byte and prints its hex value to LCD screen. In theory, this should work without issues. Baud rate is 9600, no parity, nothing out of the ordinary. On Windows I use putty, on Linux - screen. Same settings in both.
Yet, on Windows I receive hex value of 0x61 for a character, while on Linux I get 0xE1. Last 4 bits get received correctly, first 4 are not correct. Advent 7081 Laptop Drivers. @cas sure will edit - i'm not new around here:) As for being on-topic, my questions explicitly asks whether behavior of Windows uart connection is different from uart conection on Linux. This falls under category 'Using or administering a *nix desktop or server'. Lots of servers use UART, Raspberry ( and other embedded devices ) use serial connection. It also falls under 'System Interfaces'. My question is also not unclear, I am asking a very specific question: difference in serial connection on *nix and on Windows.
– Apr 21 '16 at 23:01.
All devices on Unix are mapped to a device file, the serial ports would be /dev/ttyS0 /dev/ttyS1.. First have a look at the permissions on that file, lets assume you are using /dev/ttyS1. Ls -l /dev/ttyS1 You will want read.write access, if this is a shared system then you should consider the security consequences of opening it up for everyone. Chmod o+rw /dev/ttyS1 A very simple crude method to write to the file, would use the simple echo command. Echo -ne ' 033[2J' >/dev/ttyS1 and to read cat -v. All you have to do is open two terminals. In the first terminal you cat everything from the device, e.g.
Cat /dev/ttyS0 in the other terminal, you can send arbitrary hex characters and text to the terminal e.g. As follows: echo -e ' x7E x03 xD0 xAF und normaler Text' >/dev/ttyS0 The echo -e command enables the interpretation of backslash escapes.
One has to make sure of course that (i) the serial settings (speed, word length, flow ctrl, etc) are correct and (ii) the serial device (on the other end) is not blocking. Veede Telugu Mp3 Songs Free Download.