Encode an APRS packet to a wave file which is then played through standard audio out.

transmit-aprs-packet.php

<?php
/*  This script encodes an APRS packet to a wave file which is then played
	through standard audio out. Connect your audio out to a VOX enabled
	transceiver to transmit the packet. Your audio output level should
	be rather high for VOX.

	The following AFSK/APRS Python library is required:
	https://github.com/casebeer/afsk (pip install afsk).
	PyAudio not required.
*/

function transmit_packet() {

	// Settings & variables
	$callsign = "Y0URCALL-6";
	$comment ="Listening on 146.520.";
	$alt = "000633"; // Altitude, 633 feet
	$lat = "3548.93";
	$lon = "08621.37";
	$time = date('dHi'); //092345 day:hour:minute UTC/Z
	$course = "000";
	$speed = "000";

	$command = 'aprs -c '.$callsign.' -o packet.wav "/'.$time.'z'.$lat.'N/'.$lon.'W>'.$course.'/'.$speed.$comment.'/A='.$alt.'"';

	echo "\n";
	echo "Time: ".$time;
	echo "\n\n";
	echo $command;
	echo "\n\nTransmitting APRS packet...\n";

	exec($command);
	sleep(2);
	exec("aplay packet.wav");
}

transmit_packet();

?>