Page 1 of 2 12 LastLast
Results 1 to 10 of 14
  1. #1
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Simulated Cessna 800 radio stack

    Hi Guys. Iíve almost completed this radio stack, using 6 Gables mechanical frequency coders and 3 Arduino MEGAs. The authentic feel of these radio heads is quite remarkable and the finished stack is very close in appearance to an actual mid 70ís Cessna 800 panel. The sketching was fairly straightforward, but it required a lot of cosmetic detail work and switch testing. I thought I would provide some details the radio stack here.


    Jim, you were right as usual, the COM frequencies work perfectly with the Beta release. I havenít quite figured out how to make the Com3 speaker/phones selector work, I donít know if itís possible, but Iím automatically swapping Com3 with Com2 for actual communication use based on the position of the Mic selector.
    Radio-Stack.jpg
    Attached Files Attached Files

  2. Thanks Jim NZ, dnoize thanked for this post
  3. #2
    150+ Forum Groupie
    Join Date
    Nov 2013
    Location
    Evansville, Indiana
    Posts
    243
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    3 megas? Great Googley moogley!
    I looked at the PDF...
    I guess with the mechanical displays you had to have that many connections for ALL of the digits?
    Wow.

    ~Fess
    I will only ever be, half the Geek that I wished I was.
    TheGeekForge.Com

  4. #3
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    Hi Fess, thanks for the comments. With the new version of L2fsx coming out, using additional MEGA cards is no longer a significant hurdle. Used Gables switch heads are plentiful, frequently available on ebay for under $30 (for a pair of switches), they’re just difficult to use in a home cockpit because of the wiring requirements. My old radio stack used rotary encoders and LCD displays but it was just hard to get that full immersion experience because it just didn’t have the right “feel” to it.


  5. #4
    150+ Forum Groupie
    Join Date
    Nov 2013
    Location
    Evansville, Indiana
    Posts
    243
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    SteveL, I understand the "Feel" requirement. Instead of lcd, I use MAX7219 modules to drive 4 digit, 7 segment display bars.
    If you haven't seen my earlier project "Radio Box" http://www.mycockpit.org/forums/showthread.php?t=27048
    It's kind of the "get started" prototype.
    I am currently working on an MCP/Autopilot. After that I might make a more advanced Radio Panel with more displays and more encoders for realism.

    So, in your arduino code, instead of just sending freq up or freq down, are you determining what freq is displayed on your panel and then sending the whole freq to FSX to be set?
    In other words...I think on most setups, FSX is the source the frequencies and the panel display is the reflection of what's in FSX.
    But yours being mechanical, you can't reflect what's in FSX unless you hooked up some steppers to the selectors.
    So, your panel has to be the source and then reflect that, in FSX.

    It looks like a lot of work, but I dig the "Old School" effect.
    I will only ever be, half the Geek that I wished I was.
    TheGeekForge.Com

  6. #5
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    Fess, you are correct, the switch has to determine the frequency. Forgetting about the initial “1” which is a given, there are four digits to a frequency. The Gables switch heads are configured so that it takes two contact closures to a switch common terminal to determine a digit. Each 10 number digit requires 5 switch inputs to the Arduino, the arrangement is really pretty simple. The switches make contact as follows:
    Closed Contacts Digit value
    1,2 0
    1,3 1
    1,4 2
    1,5 3
    2,3 4
    2,4 5
    2,5 6
    3,4 7
    3,5 8
    4,5 9
    Without an Arduino there is no practical way to use this information directly in fsx, but it is simple to write a sketch to read these inputs and calculate the precise frequency, the most difficult part is to figure out which wires are associated with each digit. The Arduino sends a complete frequency (4 digits) to L2fsx as a single transmission.

  7. #6
    Executive Assistant Geremy Britton's Avatar
    Join Date
    Jul 2007
    Location
    North,East England
    Posts
    1,597
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    Excellent work, well done
    Geremy Britton
    Executive Assistant, MyCockpit Inc
    Head of GLB Flight Products
    www.geremy.co.uk

  8. #7
    500+ This must be a daytime job Jim NZ's Avatar
    Join Date
    Dec 2005
    Location
    New Zealand
    Posts
    764
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    Holly Snapping duck-fish ,, what a mission Steve ,,, looks lovely and would be a treat to use ,, I wish I had something like that.

    I had a little smile when I seen the very small bit of code that goes out to my program ,,, it sinks it home doesn't it.

    I wondered if you had considered (or have the spare pins) to have 2 of the cards talk to the (say) the center one because then you would only need 1 USB cable ,,, of course you would need 4 spare pins on the "main" one and 2 spare pins on each "slaves" ,, just a thought.

    Nice work Steve and thanks for sharing ,,, Jim
    www.jimspage.co.nz/intro.htm
    All this and Liz still loves me ! !

  9. #8
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    Jim, you’ve earned yourself a new title: “Enabler in Chief”.
    The left board is completely full, except for pins 20&21 (SDA & SEL) which were left open so I could retain the option to tie them together with an I2C network. The other two have 5-10 unused pins on each, I already use I2C to drive the 7 segment DME display, and the fun has only started. I have a relatively complete set of original SkyMaster panel instruments which are just begging to be converted to servo operation.

    Can you give us novices some insight into the benefit of putting all of the Arduinos into L2FSX directly via USB vs grouping them with I2C ? Is there a magic number of SimConnects which can be monitored before the data stream begins to affect performance?

    Thanks for the enablement.
    Steve

    Ps. What is a Duck-fish???

  10. #9
    75+ Posting Member
    Join Date
    Mar 2013
    Location
    Finland
    Posts
    106
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    i has change jim.s code and working fine whit I2C LCD now if need help i can show my code.

  11. #10
    500+ This must be a daytime job Jim NZ's Avatar
    Join Date
    Dec 2005
    Location
    New Zealand
    Posts
    764
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Simulated Cessna 800 radio stack

    Thanks for that title Steve not sure if I'm worthy of it but the main thing is you got it going

    Now i2C ,,, I've never been down that road yet Steve ,, BUT when I do, I will actually be comparing i2C with Serial between the boards ,, the reason being is that i2C is great for 'daisy chaining' using the same wiring loom but serial may be better for wholesale 'dumping' of data thru to a single receiver and visa versa.

    I sort of base my (unproven) theory on my work experience where I done a lot of work with Serial and RS485 (similar principals) but there again I could be away off base with what the Arduino actually does ,, it will be an interesting experiment one day.

    You got it sorted with the i2C stuff at anyrate so that's great ,,, the good thing about your radio head is there isn't too much data flowing so combining the cards wouldn't really affect anything.

    Now the amount of serial data to one card ,, to keep things simple I've always said the serial link is always the bottleneck for the Arduino which is 'sort of' true.
    A while ago I done test's to see if I could fill the 'send' buffer in my program ,, I had EVERYTHING ticked and no trouble ,, however I wasn't processing any data at the Arduino end ,, just receiving it and dumping it ,,, the test actually surprised me.

    Now it gets messy ,,, if the Arduino is doing a lot of processing then that too can affect how much data can be sent thru the Serial for it to cope.
    So simply ,,, the amount of data is limited by the serial AND the amount of on board processing going on. (murky answer isn't it)

    The thing to watch out for is high 'change rate' extractions ,, a radio head combined with an autopilot on one Arduino is a piece of cake but if you add to that with (say) altimeter and engine RPM extractions for gauges ,,, both of which have high change rates ,, then the radiohead and autopilot could be affected ,, especially with the return data from rotary encoders. Avoid 'Delays' in any INO as well ,, they also have a big effect.

    OK ,, not much help really Steve and you probably knew all that at anyrate.

    Amazed you don't know what a duck-fish is ???? well ,,, neither do I ,, bar-less a snapping one
    It's just a very old saying without swearing I think.

    Look forward to seeing your next masterpiece Steve ,,, Jim
    www.jimspage.co.nz/intro.htm
    All this and Liz still loves me ! !

Page 1 of 2 12 LastLast