I think you're really beating yourself up the hard way. ;-) My suggestion:
get a board from http://www.diolan.com/i2c/u2c12_doc/u2c_spi_config_ss_fun.html and 7-segment driver chips from Maxim (7219) with an SPI interface (drives 8 alpha-numeric per chip) or a Maxim 6954 that drives 16 alpha-numerics or any combination of discrete LEds. Run the chips as slaves on your SPI bus and the diolan board as a master. ATM my 747 sim has over 37 discrete alpha-numerics (MCP, nav/radio panels, digital clocks, etc)- one master, (1) 6954 and (3) 7219s. The 737 that was delivered to NASA/Ames two years ago had a comparable number plus 54 discrete LEDs for warning lights, annunciators, etc Use the Network code in FG as examples on writing a socket connection and write a small program to run your hardware and connect to FG over a LAN. If you can program a micro-processor sounds like you're more than capable of handling some higher level coding.... If you get your present design approach to work, great; if not, and want to try my scheme. glad to help with design and code, your call.... Just my $0.02 John I purchased a few rotary encoder and a bunch of 7segment displays to >>> build a physical replacement of the Bendix KX165. I'm using Arduino which >>> feeds data to FGFS on a serial connection. I'd like to update >>> "instrumentation/comm[0]/frequencies/standby-mhz" property using the rotary >>> encoder, I wonder what's the best strategy. > >> I'm working on something similar too: >> http://leeds.hackspace.org.uk/wiki/index.php/Projects/FlightSimHardware > > Good to know Jon, I'll be glad to talk about that with you. > I like your hardware approach, getting your hands "dirty" on a naked ATMega16 should be fun too :-) > >> The simplest solution seems to be to simply send the active and standby frequencies whenever there's a change (up/down of the standby frequency, >> or swap of active/standby), and define a protocol that expects the two frequencies, comma separated from the serial port. It doesn't appear to matter that there's not a continuous data stream - the last received value is used if there's no new data. I run the incoming protocol at 10Hz, which seems to give a quick enough response for the on screen version of the display. > > I've settled down on sending the standby-mhz only cause I will send the swap freq <-> button state too, that will swap the frequencies inside fgfs > property tree itself, without the need to send the active freq too. Still I think it's better to make the external hardware send only the rotary encoder's rotations from a design perspective, and not the frequencies at all; I know that's debatable. I'm sending freq now for easy > of development only. > > I agree sending only changing values should be more desirable but serially > sent data should be sent all together, there's no way to send an input chunk and leaving the others as-is; since my approach aims at integrating > several (not thousands but quite a few anyway!) physical input/output devices, I think for simplicity everything should be sent at a constant frequency. And no, I find 10hz is way too low for some other devices (maybe frequency settings updates can tolerate a 10th of a second delay, but it's still noticeable). > > I'm still wondering if you too have noticed that FGFS updates it's property tree with not exact standby-mhz values when using such input devices. Can you confirm? Did you solved this issue? > > I've also noticed you use <format>%03.3f</format> in an input chunk ... I > did try that too, I hoped that would get me a 3.3 digit format but nothing! It's ignored. How's that at your side? > > > > > > > >> I'd like to be able to send values from flightgear back to the panel, so >> that updates to the properties are reflected on the radio panel hardware, but it appears I've got some bugs in my code at the moment (seems like a race condition or memory leak) that cause things to lock up or randomly reset. I need to get it hooked up to a JTAGICE to debug it. >> Jon >> ------------------------------------------------------------------------------ Create and publish websites with WebMatrix >> Use the most popular FREE web apps or write code yourself; >> WebMatrix provides all the features you need to develop and >> publish your website. http://p.sf.net/sfu/ms-webmatrix-sf >> _______________________________________________ >> Flightgear-devel mailing list >> Flightgear-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/flightgear-devel > > -- > NEU: FreePhone - kostenlos mobil telefonieren und surfen! > Jetzt informieren: http://www.gmx.net/de/go/freephone > > ------------------------------------------------------------------------------ Create and publish websites with WebMatrix > Use the most popular FREE web apps or write code yourself; > WebMatrix provides all the features you need to develop and > publish your website. http://p.sf.net/sfu/ms-webmatrix-sf > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > ------------------------------------------------------------------------------ Create and publish websites with WebMatrix Use the most popular FREE web apps or write code yourself; WebMatrix provides all the features you need to develop and publish your website. http://p.sf.net/sfu/ms-webmatrix-sf _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
