At 01:16 PM 8/08/2007, you wrote:
>Hi all,
>
>Alan W:
>
>Yep, I have seen those AIRIS PDA and they are fine, but as I will use either
>FLARM or a logger as GPS source, another GPS would be redundant. Road nav
>would be nice too. They also don't seem to have serial i/o connector,
According to a site I got to when I put that model in Google it takes
serial data at up to 115k
I suspect they just use the USB connector for this.
> USB
>only so would be unable to connect to FLARM, Vario or logger without using a
>serial to Bluetooth adaptor, which may or may not work! At least FLARM and
>Loggers have a baro pressure sensor, so one isn't relying on just GPS
>altitude for final glide and thermalling data!
If you understood what barometric pressure altitude was measuring and
the errors inherent in it, you would realise that GPS altitude isn't
such a bad way of measuring altitude for final glide.
Barometric pressure altitude is mainly useful for airspace conformity
with the rest of aviation (and avoiding disqualification for vertical
airspace infringements in contests). The pressure altimeter is
probably better than GPS just after you've set it to airfield
elevation while waiting to take off.
>It would be nice if a way of extracting the altitude/airspeed/total energy
>data from older varios and mixing it with the GPS NMEA data sentences in the
>correct format could be found, (As modern varios such as 302/B50/vega etc
>do) anyone got any ideas guys?
A few op amps, a microprocessor and some programming is all it takes
for a B20 system.
B20 systems have TE vario, indicated airspeed, true airspeed and
altitude available as analog/PWM outputs at the rear.
They are also accurate enough to be worth using(although I wouldn't
bother with the pressure altitude output) which is not true of all
older varios.
B50's already do what you want. WinPilot Pro was first produced for
the B50. Later B50's can be setup to work at 9600 baud. FLARM
requires 19200 baud for all the data last time I looked although can
be configured at lower baud rates.
The B500 has its own GPS but our new power supply/data distribution
board has the facility to use a logger or FLARM for GPS and other
data such as pressure altitude and nearby gliders and send the B500
air data and settings along with the logger/FLARM data to the PDA or
B2000/B2500 when the logger/Flarm data is available. Automatic
reversion to the B500 GPS data if logger/Flarm unavailable.
The board allows connection of logger, Flarm, PDA, communication
bidirectionally to the logger/Flarm from the PDA. 5 volt switch
mode, filtered power supply for PDA, connection to the B500 NMEA
datastream and 12 volt power and output of B500 data or composite
B500/flarm/logger data to PDA and B2000/B2500. It could be used with
other varios too.
GPS mouse devices are normally optimised for surface use. If the GPS
setups are accessible better settings can sometimes be found for aviation use.
For high current drain devices like PDAs switch mode power supplies
should used when battery powered. If you have to use a heat sink you
don't have switch mode supply. This doesn't matter in a car or
powered aircraft with a generating system.
As for the older varios: The system architecture may be such that
modifications to some later ideas may not be all that feasible or may
be prohibitively expensive. Technology also moves on and it simply
isn't worth spending much money on older systems which may be full of
obsolete/obsolescent components and which require programming
hardware and software which has to be resurrected and personnel who
have to get up to speed on what happened 10 or more years ago. The
military have the same problem with their aircraft and it is not
uncommon to replace the avionics at least once during the airframe
life to get better maintainability and performance. The earliest
glass gliders are nearly 50 years old and still flyable. Electronics
has come further than airframe design in that time.
I don't think there is much point in a pressure sensor black box as
it requires connection to the aircraft power, pitot, static and total
energy systems. It just isn't as portable as a PDA or GPS. Given it
is bolted in to the panel it may as well have a nice vario/speed
command display(B500).
Mike
Borgelt Instruments - manufacturers of quality soaring instruments
phone Int'l + 61 746 355784
fax Int'l + 61 746 358796
cellphone Int'l + 61 428 355784
Int'l + 61 429 355784
email: [EMAIL PROTECTED]
website: www.borgeltinstruments.com
_______________________________________________
Aus-soaring mailing list
[email protected]
To check or change subscription details, visit:
http://lists.internode.on.net/mailman/listinfo/aus-soaring
