Well, it's about time to play catch up with everybody. So here is my "State of the NexGen", and to tell you what's going on in my rabid brain. The big news which I sort of leaked a few days ago with my Roadmaps!
We have almost nailed down the prototype JAVA code for the Radio Sub System I/O Processor or RSSioP for short. So, for now, let us just call it the IOP. This box as gone through a Metamorphosis of sorts. Some of this code was in fact in my Simulator code when I rewrote it into C, this was a mess it displays things like DME form/to but you can't even do this without a radio. Plus I really did not want to use UDP. I was in pain for about 2 years. this was really ugly stuff. JAVA has in IGMP for groups. Basically, the IOP sends a message which states, I want to join this group.
So now I can hear the NAVserver and take Position Aircraft(lat, lon, alt) and the ground Position for the radio (lat, lon, alt). with these two locations, I can very quickly do a Slant range Calculation. If I'm less than 200 miles to the ground antenna, we now have to send messages to the DME (Distance Measuring Equipment), to display things like baring deviation, to-from flag, and power flags.
So how do we get the messages to the device sitting on the IOP? enter NASA EDIANlight communications. This allows communications from to the IOP to a local, via Ethernet, Controller. The Controller communicates over the EDIANlight protocol over multi-drop RS485 to a Slave which the device is attached to. I have settled on just ubiquitous CAT5 Ethernet net cables and jacks. As this makes life very simple.
On eBay an I found on inexpensive dual CAT5 breakout board without magnetics, but with LEDs the only thing I do is have them shipped to me without the screw terminals attached then I install male/headers and solder them in place then most of the wires are wire wrapped together one for data and power but not the LEDs and that's about it. Then I use my Ethernet Trafic Lite indicator to see any traffic (bidirectional) and the other tells me that we have a connection between two devices. this requires one device (slave or controller) to send a pulse out one port and see it at the other end. Then the other device sends it back simple (could use two wires). Then ether end sees the pulses it turns on the link light at his end.
- This can be done in a brute force method as well (my first choice) again with the two wires each side contributes a Digital Output line. this goes to the "Link Light" in the other device and then to ground. This method requires almost no software but the drawback is you really don't know when or if the downstream device is alive or dead!
- The current method uses 3 DIO ports on each pair of ATR boxes.
DataCable Pinout RJ45 (T-568B) Pin # Signal Name Color 1 Data1 white-orange 2 Data2 orange 3 Ground white-green 4 Data 1- blue 5 Data 2- white-blue 6 Power green 7 Link out white-brown 8 Link in brown
- Outputs set its output high to pull up the input of the other box
- Input with a pull-up resistor senses the High-Level signal.
- Link Light (output) will light the Link Light.
- So your wiring is the following:
- box 1a --- box 2b
- box 1b --- box 2a
- box 1c --- Link-Light box 1
- box 2c --- Link-Light box 2
One more thing.
All navigational information on the NavBus is transmitted in 32-bit BAMs. This is only converted to DMS, Mill-Grid for a Human Interface. Since the RSSioP has the FAA Nav-aid and Airport Runways, Radios, My software after downloading the new DB converts this data 32-Bit BAMs. So now when you request the DB info you can get some, all, or the fields with the BAMs. So when pilot keys in a radio (call sign lookup) the Db returns the antennas Latitude (BAMs), Longitude (BAMs), Altitude (height of, in feet), and the callsign. Since the NavBus is in BAMs as well you can do ordinary math on them and you will always get the correct answer, a BAM is defined as part of a circle. So a 32-bit BAM can be expressed as 2(base-1) where in this case the base is 32.
So here is a quick example: take a 4-bit BAM 2(4-1) The quadrants would be 0, 1, 2, 3. so that would be 0/360deg, 90, 180, 270 ok. Now the power of BAMS 111 + 011 or 270° + 180° is, drum roll please, 001 or 90°degrees. Why look at the numbers fixed point binary without overflow. If you were trying to do this is degrees this will make your head spin plus you have to take into account for the four quadrants: North, South, East, and West. So now we can say Latitude starts at North pole of 0° and the Longitude starts at Grenich again at 0° without regard for the quadrants.