Attitude indicator and VSI.

I know nothing about either for use on the Arduino, but I know what they are.

The "Attitude indicator" is sort of a "spirit level" and a VSI is a thing which shows if you are going up/down and how fast.

If I got one of these multi axis "gyroscopes" could I make one? Ok, and maybe an accelerometer

I have seen these circular LED bars which should be ok to indicate your attitude.

And if I add another accelerometer, I could also get horizontal speed. The speed could be shown with a straight LED bar.

Attitude indicator: yes. Traditional mechanical aircraft attitude indicators are based on gyros. An AI does not behave like a sprit level, because in a balanced banked turn the AI will still show which way is up.

VSI: no. An accelerometer can't tell you that you are moving (in any direction) at a steady speed. All it can tell you (not very accurately) is when the speed changes.

You could get the horizontal speed from GPS. Vertical speed and height obtained via GPS are not very accurate unless you are using augmentation (e.g. WAAS or EGNOS).

Yeah, ok. I goofed.

I said spirit level only because I was unable to think of a better way of explaining it.

VSI, ok. Could I use a barometer? Though I don't know how much it would cost and how big it would be.

So anyway, the gyro': There are 3 and 5 axis ones. Or I thought I had. http://littlebirdelectronics.com/search?type=product&q=3+axis http://littlebirdelectronics.com/search?type=product&q=5+axis (page 1) Ok, some repeats.

I shall try to work out what is going and how to use them. I have read about gyros and accellerometers. I think I have made a fool of myself. I am really new to "robotics" as it were.

lost_and_confused: VSI, ok. Could I use a barometer? Though I don't know how much it would cost and how big it would be.

You can get baro sensors such as BMP085, for which the datasheet at http://www.adafruit.com/datasheets/BMP085_DataSheet_Rev.1.0_01July2008.pdf lists "Vertical velocity indication" as one of the typical applications.