On 05/10/2005 at 13:59 Steve Knoblock wrote:
> >The model looks good. Do you have a model number for the unit? It >looks like it says BendixKing. > Bendix-King KLN 89B. There is an online manual and PC simulator (Windows only) available - you'll have to google since I don't have the links to hand. Roy sent me his original SVG files of the KAP140 autopilot as a starter for the background - thanks Roy! >I would like to see how you designed the model of the GPS unit. >Whether and how you used NASAL script to implement its functions and >how much it relies on the existing GPS unit instrument model. > >I would like to know which properties you used, the standard GPS ones >or ones internal to your GPS unit model. Perhaps both. It's all C++ - no nasal. The buttons on the unit trigger callbacks that are registered with FlightGear's command handler. I made up a "special-instrument" catorgary that gets loaded as a FG subsystem when found in the panel xml file by the panel loader, but that may be subject to change depending on Curt/Erik's view of what I've done. > >The Digitrak needs a way to know if it is receiving a valid GPS >signal. I modeled this with a manually controlled switch, but I would >prefer that it be able to look to some standard property that would >tell it the GPS is functioning and has waypoints available. If the >standard GPS is the mechanism for the GPS faceplates, then I could >look to that. Otherwise, I would need to know where each individual >GPS unit's props are or there needs to be a standard property >established. > Currently it's not integrated with the existing GPS code. It uses some of it's properties - track, groundspeed and location, but doesn't populate it's waypoint tree. However, this is a temporary situation - I believe that whatever GPS unit is running should populate the standard GPS property tree, and provide an appropriate menu dialog. I agree with your previous comments about the desirability of the autopilot providing an appropriate menu dialog - currently for instance the radios dialog sets the frequencies on the panel nav radios, but the autopilot dialog doesn't work with the KAP140. This discrepency can only lead to user confusion. The core GPS logic (cross track error / waypoint sequencing rules / approach modes etc) are fairly well separated from the KLN series specific user interface details in what I've done. Once it's in and working I'll look to merge the GPS logic with the current GPS class, to turn it into a multi-waypoint, approach capable class, that can be accessed either through the menu dialog, or through the instrument user-interface simulation on the panel. >Of course, the GPS/NAV switch is not needed because the Digitrak only >accepts course information from. > From? I assume you mean it obtains either the desired course and cross track error, or the from/to waypoint locations for your own processing, directly from the GPS, in which case you'll need the GPS unit to populate the property tree as discussed above. If it simply follows the nav needle deflection then it should continue to work, since I've modified the navradio code to output the gps-commanded needle deflection to the nav cdi when /instrumentation/nav/slaved-to-gps is set true (by the NAV/GPS switch on the annunciator). >I look forward to trying your GPS unit when you release it. > >In addition, I would like to see the Digitrak included in the standard >distribution someday, once I resolve any copyright problems with the >face. Is the face complex? Why not just knock up a new one from scratch in gimp etc. Cheers - Dave This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. _______________________________________________ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
