The control, navigation, electrical, hydraulic and logic systems of a Boeing 737NG are what you might describe as complex.  So, the more we try to simulate, the more complex our setups become.   We all start at the bottom with our Flight Sim, our favourite Add On Aircraft and the 'Must Have' Joystick.  That's when it starts to get serious...... For my project, I decided to go with the most popular short to medium range airliner of the time, the 737NG because it's modern, quick to turn round and fun.    I chose the PMDG because apart from it being a very acceptable visual and flight model, i could communicate with it via hardware MCP and CDU units. In addition, the NavData Airac cycle is updated every 28 days so i am always 'current' Trying to describe how everything works will be a very long and complex operation, so i will try to simplify it as much as possible by catagorising controls, inputs, outputs and individual items. Remember these words.....AXES, KEYSENDS, MOUSECLICKS and INTERNAL OFFSETS & PARAMETERS . These are the means whereby you actually control just about every switch, lever and control that your aircraft developer builds in to his flight model.   The first three are relatively easy to address, the fourth is a sort of grey area where you bounce between the amazing array of control that Pete Dowson gives us in FSUIPC and expensive Hardware/Software.    I tried to stay away from expensive programming and hardware, but you have to have a nice MCP and CDU don't you.  That's my only failing :o)     INSTRUMENTS	BU0836 controls my TQ Axes.   2 throttles, 2 reversers, Flaps and Spoiler  Lever.  Also controls the buttons in the TQ.  Two BU0836X are attached to my overhead to give me 64 joystick button inputs which FSUIPC catches and translates into Macro's which action the switches on the software panel.
PRIMARY FLIGHT DISPLAY & NAVIGATION DISPLAY.  First thing I did was to seperate the outside view and the panel so i could have the instruments on a second monitor.     I've lifted these from the actual PMDG 737NG Aircraft by re-writing the Panel.cfg file.    There's 2 examples of re-written files on the left which i did for other people.  My panel only contains the Instruments i need.    I used the PMDG internal instruments because my CDU is programmed with the route and it displays in the aircraft ND.  The AIRAC is always current via Navigraph and of course the FMA's are being displayed in real time as inputted to the CPFlight MCP.         If you want to know how to do this, see the 'Using PMDG for Cockpit Building' Page HERE for more information on how it was done. EICAS SCREENS  Then I had to fill the centre EICAS screen, get the standby instruments up and have a rotary flaps gauge.  So, i got these by using the excellent FSXpand from Gert Heijnis.   This is a 2 part program (the server is FSXpand, lives on the FS machine and FSClient which i run on a networked machine).    See the FSXpand page HERE or their website HERE
BU0836 (and now the all new BU0836X) Joystick Controller Card.   They're cheap, accurate and reliable.  The BU0836 (and X) card acts just like the 'guts' of your joystick. You attach potentiometers to them which control the action of any function within your sim which requires input from you over a range like elevator, aileron and throttle.   These cards allows the control of upto 8 analogue axes and additionally give you an extra 32 joystick buttons to use to input commands either direct to FS, to your aircraft or thru FSUIPC as a keysend or direct command.   Now available in 12bit version. Click here for more information. Windows will see these cards as just another joystick, so just plug it in and away you go. I use four of these cards, one is installed in the TQ (see HERE) to govern the Lever Axes and TQ pushbuttons (the Steering Tiller is also connected to this card) and the other controls numerous hardware switches in the overhead (the new Overhead will have two called CiM Overhead Controller1 and 2).     Leo has uploaded a connection diagram at his website.     Using diodes, you can input using closed (toggle) switches.           The BU0836 Joystick Buttons are read by FSUIPC and translated into either a Keystroke, a Direct Action Command into FS or the new Mouse macro's.   You can even assign one action when the switch is closed (ON) and another when the switched is opened (OFF).  For example, Landing Lights On (or OFF), Strobes On (or OFF) etc. The list is extensive, take a look at the FSUIPC Menu. All in all, a very cheap and accurate solution to control joystick axes and buttons.	BUILDING A TQ? Hook it up via the BU0836 Controller. HERE's HOW
The CPFlight MCP communicates with the PMDG by way of the FS_COM utility which they provide in their CPFlight Tools package.  Once set up correctly, it is 100% reliable and faithfully reproduces the commands and behaviour of the Boeing MCP.  This is a 'must have' addition to any cockpit.  there's a basic explanation of what it does HERE.	10/10 for this one chaps :o)
The CPFlight MCPEX1 is the first expansion board i bought. It connects via the MCP and is configured by way of the MCP_CONF utility which CPFlight again give you in the CPFlightTools Package.  64 digital inputs for switches or pushbuttons give a lot of room for expansion.   I use all of them.  Each input can be configured for a direct FS command or to send a key forward.  There are 10 relay outputs which i use to light several LED's at certain action times like the landing gear, parking brake Indicator and the stall warner etc.  All in all a good add-on if you have the CPFlight MCP.  I found the inputs for the variable potentiometers a little too unreliable, so i dont use these at all.  I prefer the accuracy which the BU0836  gives me.	8/10 only the axes sensitivities let it down. A Good Add On If You have the MCP737
The CPFlight MIP737 OK i had a bad experience with my first MIP737 board. I just could not get it to work properly.  After intense e-mails with Paolo at CPFlight, he agreed to replace it.  It turned out that i had a faulty unit.  You cant bitch about the backup CPFlight give, it is first class.   Now we have the MIP annunciators running true to form with one small exception, the autobrake disarm, but Paolo is going to look at the way FS_COM reads the data from FSUIPC and correct it.   Read the manual at CPFLIGHT here for the list of functions and available annunciators that you can lift with the PMDG using the MIP737.  I take back everything i said about this board now it works :o)	8/10   Adds that certain something to the MIP when the annunciators light up
The ENGRAVITY CDU is another 'Must Have' Unit.  You have to buy the interface software from PMDG for $99 to run it with the PMDG 737NG, but trust me it's money well spent. (Well it isn't now because of some Political Motivation over a copyright issue, this driver is no longer available).      This unit gives you exactly what you see on the software CDU.  Every page and function is authentically reproduced.   It's so much more realistic commanding your aircraft's flight route and performance inputting via the keypad and reading out the results on the built in LCD Display.  Every aspect of performance, routing, navigation is faithfully reproduced exactly as you would see it on the screen.     And having had experience of FlyEngravity's backup service and repair facility (i dropped my CDU), I highly recommend this add-on.   If you're going to buy something for your 'PIT', buy this and the CPFlight MCP First.
NAV & COM Radios The Nav/Com Radios are from Flight Illusion. I bought a set of 2 Comm, 2 Nav and the ADF from Mark because at the Lelystad show 2006, he had a special deal if you bought the 5 he would throw in the GSA-55 controller.    I have to say they work exceptionally well and after a year of service, they are still beavering away everyday.  Reliable and effective.    The only drawback is that they do not make a Transponder.  But that's not the end of the world, our Italian colleagues do :o) The 737NG TRANSPONDER came from CPFlight.  It's OK, but there is an abnormality with it.  In the standby position it displays F8888 (a test display) and not the actual squawk code.  so you have to turn the Transponder to an active mode to change the squawk code.    Paolo tells me he cannot do anything about this because the function is in the firmware which he cannot change.   Wouldn't it be nice if everything worked as it should.
FSUIPC   This has got to be the most important and popular interface add on's we have available.       A registered version gives you unparallel  access to so many functions, actions and possibilities.    All references made and functions described here are for a registered version.       Because FSUIPC is a module, it loads and works as part of FS.   FSUIPC reads and writes data to FS.   It is the interface that allows you to do something and then translates that input into an action which it commands FS to execute.     It also reads data and sends it back to your add-on or aircraft as a user friendly output which is delivered to 3rd party programs like FSXpand/FSClient, Squawkbox and Active Sky.  So it follows that it,  as well as FS or your add-on, is waiting to read and act on an input.   It sees joystick buttons and can then translate that button press into an exact given function or a keysend.  Not only that, it gives you one action when you press the button and another when you release the button.  So connect a toggle switch and send the button via a BU0836 Joystick Controller Card and one switch will give you a distinct ON/OFF instead of a 'Toggle'.      Read the manual and experiment.   Spend the weekend playing with the FSUIPC menu's.   It's time well spent and you have the rest of your life to enjoy the benefits :o) FSUIPC also reads keysends (whether you have pressed the keyboard or use a keyboard emulator).  These keysends are again translated into actions as are the joystick buttons. Then you have the Axis (Axes) Menu Pages.  You assign your axis first on the assignment page, then calibrate and fine tune it in the Calibration pages.   I have removed control of all the Axes from FS and send them all to FSUIPC for processing.  Much more accurate i reckon.       The clever thing Pete Dowson has done is to include the function of  accurate positioning on the axis in steps.   A good example is the FLAPS.    I have 9 flap positions ranging from 0 to 40 degrees.   On the TQ, the flaps handle sits in little detentes at each flaps position.   I am now able to calibrate that position exactly, so when i set flaps 15, that's exactly what i get. I am only trying to give you an insight into what i do with FSUIPC.  It is such an amazing program that i suggest you read the manual that Pete gives you in the download zip and understand what it is capable of.   You are going to be amazed.    It's such a inexpensive way to get a whole lot more out of (and into) your sim.
AXES Accurate and realistic control of your aircraft is a must. Therefore it follows that correct calibration and sensitivities are important for successful operation.  All inputs whether they be from the Yoke,Rudders or the TQ are calibrated in the Windows Game Controllers Page first.   Once calibrated, i disable any influence on the controls from FS itself.  All axes are assigned and configured from within FSUIPC, first by assigning them in the Axis Assignment Page and then 'tweaking' them in the Joystick Calibration Page. Read the FSUIPC Manual for instructions how to do this.   You can get it HERE Axes assigned in FSUIPC are both Yokes, using the X & Y axes on seperate BU0836X boards so i can 'centre' them.  All 3 axes on each set of rudder pedals, the Steering Tillers and the 6 TQ axes.
Manual Trim. The Symulatory TQ trim wheel shaft is fitted with a gear which originally rotated an encoder.  I have replaced the encoder with a pulse switch and then connected that to two of the joystick button inputs on the BU0836 card.  What the switch does is only contact (ON/OFF Momentarily at each detente) in the direction of rotation.  So as i turn the trim wheel, i get a single (or continuous) On/Off switch state on the joystick button which is connected to that directional input.  This has the same effect as repeatedly pressing a joystick button.  Then the button is assigned in FSUIPC as Elevator Trim UP or DOWN (depending on which way the shaft is turned), resulting in accurate control of the elevator trim. I've wired this thru the Stab Trim Switch on the TQ so i am able to switch manual trim on and off       There's more information about PULSE SWITCHES on the TECHNICAL PAGE including links to Data Sheets.
Nosewheel Steering Both Steering Tiller's came from ROUTECH in Romania. I made a small frame to join a centre shaft passed thro the tiller to a potentiometer. This in turn has been connected to one of the Axes on Leo's BU0836 Controller Card.  FSUIPC allows you now to assign a Joystick Axis to the nosewheel steering.  The Steering Tiller and the Rudder have an in built 'Speed Curve' (MaxSteerSpeed) whereby Pete Dowson has set a value under which the Tiller has authority and over which the rudder has command (for example 50kts).  As speed increases on the ground, control passes progressively from the tiller to the rudder and vice versa.   Works very well and is very accurate.
The Electrical System.    I have now managed to Automate the Electrical Systems.    This was a project that took me 9 months to complete.  It was great fun and a real challenge.    I'm writing up the docs at the moment (10th Jan 2010).
The Following Items are Not used any longer, but i have left the information in here because i still get asked about them from time to time.
USBKEYS Card Comes from OPENCOCKPITS in Spain.  It's a keyboard emulator, that is, by bridging across any two points on a 11 x 8 matrix, you can send upto 88 seperate key combinations which will be read by FSUIPC, FS or your Add-On Aircraft/Utility.  They are very cheap, reliable and once you get your head round connecting to it and writing the .ini file, they are a dawdle to use.    Drawback is they  don't like switches which are left permanently on unless you use diodes in the matrix and they also don't repeat keysends. There's a .pdf file HERE to make life easier when trying to set up your OPENCOCKPITS USB Keys card.... Go on, be adventurous.
GoFlight RP48 Remote Kit  I have tried several ways to get rotary encoder input into the sim succesfully, but unless you want to spend a fortune, this is the most simple way i have found.   It works, FSUIPC recognises this Remote Kit as though it was an actual GoFlight RP48.  Consequently, you can assign any FSUIPC function (or send a keystroke) from each of the 4 encoder inputs per board. Each encoder is recognised as four seperate buttons, one for CW and one for CCW dependant on whether you rotate them slowly or quickly.   Additionally, you also have the ability to add 8 more joystick pushbuttons (and have LED outputs (dependant on what you use the buttons for).       There is a need for different inputs based on the direction of rotation of a control.       Good examples are the Trim (up/down), EFIS Control Functions or any other repetative input based on the direction of a control. The reason i wanted an encoder for button switching input  was that I found potentiometers too 'twitchy' and inaccurate.       One word of warning, the GoFlight remote encoders come mounted on a board and do not have a threaded collar, so you cannot attach them thru a lightplate.   I found a replacement encoder from ALPHA in Taiwan at MOUSER ELECTRONICS.   Here's the DATA SHEET.  It's also available with a push action switch for use on the EFIS units. There's a very good document HERE at GoFlight about using the RP48 with the PMDG	700111 Encoder