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  • Author Author: phoenixcomm
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NexGen: Radio SubSystem Overview

phoenixcomm

Ok I am going review some of the RSS as it is changing but in a good way..image

image

Figure 1.
RSS Block Diagram



The RSS_IOP has a lot of jobs (review):

    1. Physical radios themselves.
    2. The radio's interface system  (arduino cards).
    3. Driving some intruments (flags, lights, etc)
    4. The interface to NavGroup intranet ( and decoding messages).
    5. Morse Code generator.
    6. FAA radio data base. (mySQL)
    7. Radio simulator.
    8. Line of sight calculations (between radios and aircraft)
    9. Crew audio station(s).
    10. Moving audio from different sources to the right audio line (LASA Patch Bay)

Currently we will only concern our selves with the radios functionality 1 and the interface system 2.

The radio model has been changed thankfully to a UML editor from Mentor Graphics.


The Analysis:


image
Figure 2.
RSS Radio Model

We can look at a radio in three (3) parts;

  1. The physical radio (common to all radios). This is the structure referred to as radios[]. This is an array of all the radios.
  2. The interface. This is was makes each radio unique.  This is the structure referred to as radio_XXXX.
  3. The tuner or tuners. The tuner is just that. It hold the tuned frequency, and its file descriptors. This is the structure referred to a tuner_XXXX.

Each one of the structures need a forward reference ie. a pointer to the next lower structure. So when we get a interrupt from one of the tuners, we can just grab the right tuner. But what if we have turn on/off in one of the upper structures? We added two (2) backwards references, or pointers in the tuner's structure.


The protocol between the interface card (arduino) and the RSS_IOP is as follows:


Between the arduino and the RSS_IOP: 3 bytes;  1 RADIO_ID, 2 SWITCH, 3 DATA. Then the RSS_IOP NAC's or ACC's back;


Between the RSS_IOP and the arduino; 3 bytes;  1 RADIO_ID, 2 OUTPUT, 3 DATA. Then the arduino NAC's or ACC's back;


Radio Head (Hardware):

 

Any radio head can be interfaced to the system, such as:

  • ARINC-410:  Decoding is done on the RSS_IOP
  • ARINC-429:  Separate interface card in the RSS_IOP 
  • MIL-1553:     Separate interface card in the RSS_IOP 
  • Custom:        You build it, well make it work



image Keep tuned in, More to come

~~ Cris

  • Hi Chris,

     

    I like the interface using the microcontrollers.

    Back in the early 1980's we proposed a similar system for an aircraft maintenance simulator.  It worked quite well and eliminated a lot of ancillary gear to do all of the aircraft interfacing.

     

    So I think you are in good shape.

    I bet you can't wait to dial in your first radio link to test the audio.

     

    DAB