venerdì 24 dicembre 2010


I finally managed to have the altimeter WORKING!!!
The job has been done by replacing the existing resolvers with 2 pots: one for the altitude and one for the QNH.
The problem by interfacing it with the OC card is the crap resolution of the A/D...only 8 bits....that means 256 steps. It could be ok for gauges like VSi or ASI but the altimeter? it has a rotating drum which goes from - 1000 to + 50000 feet. that means that if we can manage this excursion for the whole rotation of the pot we have the ridiculous resolution of 51000 / 256, so 200 feet for each step!!!! it's simply not usable for an think that the mechanical rotation of stock gearing makes the 51000 feet excursion in less than half turn of the pot so the precision halves to 400 ft or more!!! it's just CRAAAAAAAAP!!!! to over this problem? We need an higher resolution A/D converter if we want to preceed with the DC motor way.

There are no cards around for motor driving with an easy interface for FS which have a resolution higher that 10 bits, and I'm not so expert to build one and make a code for it. So?
The solution comes frrom the Leo Bodnar's joystick card. It has 12 bit resolution A/D which means 4096 steps per revolution. Counting half revolution with stock gearing we still have around 2000 steps for our scale which means a resolution of bit more than 20ft!!! Now THIS is acceptable resolution!!!
But now the question: how do we do that?
FSUIPC is the answer!
After connection the pot to the joystick card, we go into the FSUIPC Axis assignement menu and we assign the altimeter drum axis to an external free offset (Starting with $66C0) as a dWord setting DELTA value to 1
Same is for the QNH which we'll assign to another offset. But with a Delta higher as 32.
The Offsets comes out with a reading of 15bits from -16364 to + 16383,  but we only want to read it as a normal 12 bit axis. We manage to do that in the FSUIPC4.INI file where the assignements has just been done. (Thanks to my friend Gery for his help!)
Under the " [AXES] " section look for the 2 axis you recently added. you should have 2 lines like those:
Now we want to use only the positive range and divide it by 4 to limit the reading from 0 to 4096.
We do that by halving the readout value, dividing the result by 4 and adding 2048 to stay in positive range.
This is how lines should look with this adjustement

Now just read the offset in SIOC and use the value as reference pot. (the offset length is 4)

You will find the complete code at top of the page in SIOC CODE section along with rest of cockpit.

domenica 19 dicembre 2010

Character LCD Comm 1 and 2 module

here is an unusual approach to the Comm 1 and 2 radios interfacing which gives a really nice and realistic result.
2 years ago I had a deal and I got 2 real VHF Comm modules out of a 767 manufactured by AVTECH which I disassembled to see how to modify them in order to work with OC cards.

The removal of stock electronic has been quite easy but during the removal of the original LCD panels I got the idea: why don't try to replicate a similar result?
So after a bit of research on the net i found at Crystalfontz a LCD which coulded fit in terms of dimensions to the stock housing and I bought them.
They are 2 lines x 8 characters LCD displays featuring white chars on dark background which is what the stock LCD looks like.
After assembling and cabling everything up I made a first test to see how everything was operating and this is the result:

So as a first test I was really enthusiast but then lot of programming woulded be required in SIOC to make the thing working.
Basically for each display there are 3 virtual pages.

  • First one is empty and is called either when there is a failure detected or the appropriate power bus is off so it doesn't allow any tune or frequency display.
  • Second one represent the ACTIVE frequency and display the appropriate tuned frequency with the -ACTIVE- displayed in the 1st line. When this virtual display is active in the 1st phisical display, the active flag offset is on as well while in the 2nd phisical display the active flag is obviously off.
  • Third one represent the STANDBY frequency and in this page the frequency is the same as the active virtual display but -ACTIVE- is nomore displayed and the active flags is switched to off and at the same time switched to on in the 2nd phisical display.
This is how the real unit also operates and gives that piece of realism on a module which is really used during flights, specially online as i implemented the IVAP offsets to work according to the comm frequency and state.

venerdì 17 dicembre 2010

Throttle shots

Here you can see the Throttle quadrant when arrived at my place last year.
It was in great condition, only really dirt, specially the mechanic inside :D
I added the 2 real HSI panels I collected during time. one is complete the other one is gonna be :)
Actually i'm working on a mechanism to interface the throttle levers, spoilers, flaps and stab trim and implementing motorization as required. I'll post more on that once there will be progress!
I chosed to not repaint it as personally I really like to keep the "used and lived" style, it makes me more enthusiast :)

MCP complete

Here are some shots of the MCP finished. This unit has a metal chassis and features real Korry pushbuttons lighted with 28V incandescent lamps.
The unit implements all the 767 features and is interfaced via OC Cards to FSX.
The hardware for glare section includes one Mastercard, one (2 when Navs will be operative) Display card and one USB Outputs card.
Proper script has been made to include light test for the Korrys, the backlight and the digits, and bus state logic is implemented according to 767 manuals.
The lightplate is provided by my friend Philip Lambert, owner of SIMVIONICS.
The glare section will soon be updated with NAV 1 and NAV 2 modules.