A simple AX.25 packet monitoring example script.

exec/examples/ax25monitor.js

+/*	ax25monitor.js
+	echicken -at- bbs.electronicchicken.com (VE3XEC) */
+
+/*	A simple AX.25 packet monitoring script.
+	(Try using it to monitor APRS traffic on 144.390 MHz) */
+
+load("sbbsdefs.js");
+load("kissAX25lib.js");
+
+/*	This script requires one argument, the name of a TNC that's defined in
+	ctrl/kiss.ini. (Eg., if you have a PK88 TNC defined in your kiss.ini
+	file, its section name might be [PK88], so pass "PK88" as an argument
+	to this script. */
+if(argc < 1) exit();
+
+/*	This is where we load the section of kiss.ini that was specified as
+	an argument. */
+var f = new File(system.ctrl_dir + "kiss.ini");
+f.open("r");
+var k = f.iniGetObject(argv[0]);
+f.close();
+
+/*	Having loaded the TNC's configuration details from kiss.ini, we now create
+	a kissTNC object based on that information: */
+var tnc = new kissTNC(argv[0], user.comment, 0, k.serialPort, k.baudRate);
+
+var kissFrame;
+var msg;
+
+console.clear();
+while(!js.terminated) {
+
+	// Hit [ESC] to exit :D :D :D
+	if(ascii(console.inkey(K_NONE, 5)) == 27) break;
+
+	/*	kissTNC.getKISSFrame() is kind of a misnomer.  While it does read a
+		KISS frame from the TNC, what it actually returns is an AX.25 frame
+		(less the start/stop flags and frame check sequence) in the form of
+		an array of bytes, or false if there was no frame to be read. */
+	kissFrame = tnc.getKISSFrame();
+	if(!kissFrame) continue; // See what I said re: 'false' above.
+
+	/*	So, if we've gotten this far, then we have an AX.25 frame to decode.
+		We'll create a new (empty) ax25packet object, then disassemble the
+		array that tnc.getKISSFrame() returned to us in order to populate
+		the object with properties. */
+	var p = new ax25packet();
+	p.disassemble(kissFrame);
+
+	/*	So now our ax25packet object 'p' has a bunch of properties.  We won't
+		print all of them out since most of them won't be useful to you as a
+		dev or as a user simply watching traffic.  Instead we'll just print
+		the source and destination callsigns and SSIDs, plus the digipeater
+		path taken by the packet (if any).  If the packet has an information
+		field (ie. it is an I frame, a UI frame, or a U FRMR frame) we'll
+		print that out as well. */
+	msg = p.source.replace(/\s/, "");
+	if(p.sourceSSID > 0) msg += "-" + p.sourceSSID;
+	msg += " -> " + p.destination.replace(/\s/, "");
+	if(p.destinationSSID > 0) msg += "-" + p.destinationSSID;
+	if(p.repeaters[0] != 0) msg += ", repeated by: " + p.repeaters.join(", ");
+	if(p.hasOwnProperty("information")) msg += "\r\n" + byteArrayToString(p.information);
+	console.line_counter = 0;
+	console.putmsg("\1h\1w" + msg + "\r\n\r\n");
+}