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daniel widyanto (kunilkuda at gmail dot com)
20 years ago
I'm using PHP to interface my AVR microcontroller in /dev/ttyS0. I bet someone else does the same.

Here's some hint :
- dio_tcsetattr -> is set to enable :
- RTS / CTS hardware control
- ICANON mode
(means that dio_read will wait until 0x0A/LF or other control character is entered in /dev/ttyS0 before it returns reading result, when you use dio_write it will also send 0x0A/LF automatically in the end of the message to your device).

For those who dont need RTS/CTS and/or ICANON, you can use linux command : stty.

Here's mine :

<?php
exec
('stty -F /dev/ttyS0 4800 raw');

$fd=dio_open('/dev/ttyS0',O_RDWR | O_NOCTTY | O_NDELAY);
dio_fcntl($fd,F_SETFL,0);

dio_write($fd,"\x41",1); // write 0x41 or 'A' to /dev/ttyS0

// Replace result_length with your expected command result length
for ($i=0;$i < result_length;$i++) {
$result .=dio_read($fd, 1);
}
echo
$result;
?>

Refer to :
- Serial Programming Guide for POSIX Operating Systems, http://www.easysw.com/~mike/serial/
- stty man pages

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