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Old Jul 20, 2011, 02:12 PM
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Just looking over the V4 Altimeter and was wondering about its time response. In otherwords, to get the 1 foot resolution, how fast does the sensor respond to altitude changes? I am not talking about the data recording rate, that is fine, but if the sensor value is from the previous second in time, then that would be a problem.

My application is a bit specific ----I fly control line planes where the maneuvering is abrupt, and the altitude varies between 3 to about 65-70 feet max. I try to correlate the altitude to power levels into the engine (and rpm) and so was a little worried that there might be a delay (due to averaging or filtering in the sensor itself. This would make it hard to compare two different readings. The time scales that interest me are in the 0.1 to 0.2 second range, where I would expect the altitude to change by values in the 1 to 3 foot range.

Thanks...Also interested in the new 3 Axis accelerometer for the same application, and have similar questions about its time response.
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Old Jul 22, 2011, 03:51 PM
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Hi Alan,

There should be no issue with both sensors detecting those changes in a 0.1 second interval. They also have updateable firmware (with eLogger), so so let me know if they not working as desired.
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Old Jul 23, 2011, 12:43 PM
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Hi,

I have the airspeed sensor, and i was wondering whether it should need correction for altitude.
It looks like it already has some kind of temperature correction, but what about altitude? I'm up to 800 to 1000 m high at home so the air density is quite different from sea level.
Furthermore, what is the real accuracy of this sensor? +/- 1 km/h? 2 km/h? ...

Guillaume
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Old Jul 29, 2011, 11:15 AM
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3rd party mode for Altimeter v4

Hi Bill, I recently bought an Altimeter v3 and was able to read the data off of it via i2c interface with an Arduino board using the code posted by turnale and nakki5...it was not in 3rd party mode, but I was able to figure out the scaling parameters to convert the raw data to height in feet.

I have since upgraded to the altimeter v4, and now the same code does not seem to work (no bytes are available to be read from the sensor). Any idea why it would work with the v3 but not the v4? (I requested the v4 be put in 3rd party mode when I ordered it, but it's not clear from the documentation whether that's even an option on the v4).

Thanks for any help...


...got it resolved thanks!
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Last edited by dhertzog; Aug 08, 2011 at 11:37 AM. Reason: resolved
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Old Aug 26, 2011, 08:11 PM
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Bill, how long is the wire that goes from the altimeter to the receiver. I have a Radian Pro and I'm trying to figure out where to put your device and how much wire I need to go to the receiver. Can a servo extension wire be used if yours is to short?
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Old Aug 26, 2011, 11:04 PM
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United States, AK, Anchorage
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I just measured my wire and it came in at around 5 1/2 inches.

Also, it's a 4 pin wire so a standard 3 pin servo extension isn't going to work.

-Mike
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Old Aug 27, 2011, 06:16 AM
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Thanks Stone...but I thought the wire for the standalone altimeter plug directly into your receiver. Maybe I have to go back and re-read the ad. I know the wire going into the logger was 4 wire but I assumed the one going into my Spektrum receiver was only three. Thanks for your time on this question.
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Old Aug 27, 2011, 10:44 AM
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I've got my altimeter plugged into my OSD Pro so I'm only familiar with that setup. There might be another way to do it.

-Mike

Edit...

You're right! You can use a 2 pin converter cable that only supplies power to the unit and that plugs into your Rx. Take a look at the manuals here:

http://www.eagletreesystems.com/Support/manuals.htm
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Last edited by Stone1295; Aug 27, 2011 at 10:49 AM. Reason: Rx setup
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Old Sep 15, 2011, 04:52 AM
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Hi Bill,
just a question, I have an OSDpro on my sailplane, and I would like to use this barometer to detect if I'm on a thermal. Now that you have increased the accuracy, and since I use meters as a unit, can I read full accuracy of the sensor? meaning for example 5.6m and not just integer numbers?
2. The speed is also important, how fast will I see the data on the screen is also important, so what is the delay between the the actual sensing and the updating the value on the OSD?
Thanks
Sp1k3
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Old Dec 14, 2011, 04:49 PM
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I just brought the Altimeter sensor and the reading dont seem right.. maybe its the place i was at.. how do i resset it
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Old Dec 21, 2011, 01:02 PM
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Hi, there is no need (or way) to reset it. Can you give more info about the issue you are seeing?
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Old Dec 21, 2011, 03:01 PM
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Does the sensor read from sea level? Or when I plug it in it zero out depending where I am at?
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Old Dec 21, 2011, 07:06 PM
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After you plug the battery in it displays the last altitude that it registered. Then it starts registering again once your aircraft had reached 60 feet. It is not registering above sea level, just the altitude from your starting point.
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Old Jan 06, 2012, 06:14 AM
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ok sorry for chiming in so late
is eagle tree making the spektrum airspeed sensor??
Since I dont want to buy 29837923879 airspeed sensors. can I at least buy the pitot tube and some silicon tubing to swap it into planes???
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Old Jan 06, 2012, 08:38 PM
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You can use the airspeed unit on any rx
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