Searching \ for 'Altitude stuff with a pic' in subject line. ()
Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'Altitude stuff with a pic'.

Truncated match.
'Altitude stuff with a pic'
1998\11\13@021841 by

> Lo there all

Who knows how to calculate the altitude using a pic. I have built all the circui
try for all, just the altitude stuff now...

I have a fancy formula (email me if you want it) but I am looking for an easy on
e that even a pic can do......  I have to enter the QNH (corrected air preasure
for a given altitude, typically 1.013 bar at
sea level) and it must spew out the height in feet (or meteres...) whatever is e
asier.
I am using a PIC73 with two Differental preasure transducers (one for air speed
and the other for altitude)

any help
Richard

Send email to
richardwasp.co.za

---
Any tresspassing spam will be shot.... all surviving spam will be shot again

On Fri, 13 Nov 1998, Richard Parsons wrote:

>
> Who knows how to calculate the altitude using a pic. I have built all the circ
uitry for all, just the altitude stuff now...
>
> I have a fancy formula (email me if you want it) but I am looking for an easy
one that even a pic can do......  I have to enter the QNH (corrected air preasur
e for a given altitude, typically 1.013 bar at
> sea level) and it must spew out the height in feet (or meteres...) whatever is
easier.
> I am using a PIC73 with two Differental preasure transducers (one for air spee
d and the other for altitude)

For altitude (in PSI):

alt = 14.7-((feet*(52.85 - (0.000673*feet)))/100000.0);

This is only good to about 12,000ft though, but I use it
for diving decompression, and most people don't scuba dive
higher than that.  It sounds like your doing avionics, so
this won't help.

FWIW,

-Will

Richard, If you are still looking for pressure/altitude information, I
noticed there is a free web based class on building a recording
altimeter for rockets at http://www.rocketryonline.com.  Look at the lower
right hand part of the home page for the alt101 class.  This one is good
to 15000 ft so I would expect it to use a reasonable model.  They're
programming a device similar to Parallax's Stamp.

Felix

> {Original Message removed}

William M. Smithers wrote:
>
> On Fri, 13 Nov 1998, Richard Parsons wrote:
>
> >
> > Who knows how to calculate the altitude using a pic. I have built all the circuitry for all, just the altitude stuff now...
> >
> > I have a fancy formula (email me if you want it) but I am looking for an easy one that even a pic can do......  I have to enter the QNH (corrected air preasure for a given altitude, typically 1.013 bar at
> > sea level) and it must spew out the height in feet (or meteres...) whatever is easier.
> > I am using a PIC73 with two Differental preasure transducers (one for air speed and the other for altitude)
>
> For altitude (in PSI):
>
> alt = 14.7-((feet*(52.85 - (0.000673*feet)))/100000.0);
>
> This is only good to about 12,000ft though, but I use it
> for diving decompression, and most people don't scuba dive
> higher than that.  It sounds like your doing avionics, so
> this won't help.

Yes - he's doing a crash-course in microlight flying!
(Hi Richard!)

--
Friendly Regards          /"\
\ /
Tjaart van der Walt        X  ASCII RIBBON CAMPAIGN
tjaartwasp.co.za  / \ AGAINST HTML MAIL

|--------------------------------------------------|
|                WASP International                |
|R&D Engineer : GSM peripheral services development|
|--------------------------------------------------|
|SMS tjaartsms.wasp.co.za  (160 chars max)|
|     http://www.wasp.co.za/~tjaart/index.html     |
|Voice: +27-(0)11-622-8686  Fax: +27-(0)11-622-8973|
|          WGS-84 : 26¡10.52'S 28¡06.19'E          |
|--------------------------------------------------|

1998\11\16@010519 by
Question, are you going to be able to enter the QNH or is 1013 going to be
the default? It won't be to accurate if you always use 1013 as the presure
changes all the time and you don't always take off at sea level.
Standard formula used by pilots for presure height is 1 bar = 30 ft of
altitude.
eg Take off Sea level at 1000 bar
Cruise at 3000 ft then presure will be about 900 bar

But if you going to this extent why not calcutate desity height too.
International Standard is 1013.2 bar at +15 deg C.
Stick in a temperature probe and calculate your density height. Rough
calculation is every 1000ft you climb you loss 2 deg C
Check out a Privat Pilot training manual at an aero club.

Regards Jason.

William M. Smithers wrote:
>
> On Fri, 13 Nov 1998, Richard Parsons wrote:
>
> >
> > Who knows how to calculate the altitude using a pic. I have built all
the circuitry for all, just the altitude stuff now...
> >
> > I have a fancy formula (email me if you want it) but I am looking for an
easy one that even a pic can do......  I have to enter the QNH (corrected
air preasure for a given altitude, typically 1.013 bar at
> > sea level) and it must spew out the height in feet (or meteres...)
whatever is easier.
> > I am using a PIC73 with two Differental preasure transducers (one for
air speed and the other for altitude)
>
> For altitude (in PSI):
>
> alt = 14.7-((feet*(52.85 - (0.000673*feet)))/100000.0);
>
> This is only good to about 12,000ft though, but I use it
> for diving decompression, and most people don't scuba dive
> higher than that.  It sounds like your doing avionics, so
> this won't help.

Yes - he's doing a crash-course in microlight flying!
(Hi Richard!)

--
Friendly Regards          /"\
\ /
Tjaart van der Walt        X  ASCII RIBBON CAMPAIGN
tjaartwasp.co.za  / \ AGAINST HTML MAIL

|--------------------------------------------------|
|                WASP International                |
|R&D Engineer : GSM peripheral services development|
|--------------------------------------------------|
|SMS tjaartsms.wasp.co.za  (160 chars max)|
|     http://www.wasp.co.za/~tjaart/index.html     |
|Voice: +27-(0)11-622-8686  Fax: +27-(0)11-622-8973|
|          WGS-84 : 26010.52'S 28006.19'E          |
|--------------------------------------------------|

More... (looser matching)
- Last day of these posts
- In 1998 , 1999 only
- Today
- New search...