Arduino Variometer In A Mint Tin

While humans have done a pretty good job of figuring out how to fly with various mechanical contrivances, the fact remains that our natural senses aren’t really well suited to being off the ground. For example, unless you have a visual reference point, determining which way is up is quite a bit harder than you might think. Which is why pilots rely on instruments such as the variometer, that determines the current rate of climb and descent, to guide them when their eyes can’t be trusted.

It’s also a very handy thing to have when paragliding, which is why [mircemk] decided to build a hand-held version using the Arduino Nano and a BMP180 pressure sensor. Since you don’t want to be staring at a little screen in mid-air, the device conveys changes in altitude with audio tones. A rising tone means you’re moving upwards, while a lower tone indicates downward travel. In the video below, you can see that it only takes a meter or two of vertical movement before the device picks up on the change.

Looking for a simple yet rugged enclosure for the device, [mircemk] found a metal mint tin that would hold the microcontroller, sensor, buzzer, and the 9 V battery that powers it all. We know what you’re thinking, but don’t worry; holes have been popped in the sides to make sure there’s no pressure difference inside the tin. There’s plenty of room to replace the alkaline battery with a rechargeable pack and associated charge controller, but we imagine there’s a certain security in tossing in a fresh new primary cell before slipping the surly bonds of Earth.

If you’re in interested DIY instrumentation for a glider or other aircraft that actually has a proper cockpit, this sunlight readable flight computer made from a Kobo e-reader would be a great start.

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PropVario, A Talking Variometer/Altimeter For RC Sailplanes

propvario

Lift. For a sailplane pilot it means the difference between a nice relaxing flight, or searching for an open area to land. Finding lift isn’t always easy though. This is especially true when the sailplane is hundreds of meters above a pilot whose feet are planted firmly on the ground. That’s why [Tharkun] created PropVario. PropVario is a combination variometer and altimeter for Radio Controlled sailplanes. We’ve seen a few variometers in the past, most often for full-scale sailplane or hang glider pilots. Almost every full-scale plane has a variometer as part of its suite of gauges – usually called a rate of climb or vertical speed indicator.

R/C pilots don’t have the luxury of looking at a gauge while flying though. At altitude even large 2 meter gliders can appear to the naked eye as no more than a dot. It would be somewhat embarrassing to lose sight of your glider because you were checking gauges. The solution is actually simple. A varying audio tone indicates the rate of climb of the plane. Higher pitched tones mean the plane is going up. Lower pitched tones mean the plane is descending. This system, coupled with a simple radio transmitter, has been in use by R/C sailplane pilots for years.

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Variometer Build For Gliding Aircraft

If you’re flying through the air in a non-powered vehicle your rate of descent is something that you want to keep any eye one. With that in mind, [Adrian] decided to design his own Variometer (translated) what will have a place in the cockpit next to the other instrumentation. It emits a pitch whose frequency is dictated by the rate at which altitude is being lost or gained.

He went with a PIC 24FJ64 microcontroller to drive the device. It’s reading data from an MS5611 barometric pressure sensor. This measures changes in air pressure associated with a change in altitude. As a user interface he chose one of SparkFun’s Nokia 5110 LCD screen breakout boards. He also went with one of their boost converts which lets him power the device from just one battery cell. The case itself is cut from several layers of plastic using a CNC mill.

In the video after the break you can see how sensitive the device is. Moving it just a few feet up or down has an immediate effect on the sound and the displayed data.

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DIY Cell Phone Alti-variometer

AltiVarioFront

[Vlad-Andre] used some of his free time to build an alti-variometer. He does some para-gliding near restricted air space and wanted a backup altitude warning that would help keep him below the mandated altitude. His solution uses the SparkFun Weather Board in conjunction with their BlueSMiRF dongle to measure altitude and transmit it via Bluetooth. From there, he wrote a program to grab the transmitted data with his cell phone and display the information. His application also has the ability to set altitude warnings and log changes over time.

Using this system he is able to get altitude data with 3.5 inch accuracy. Because the capture application is written in Java it should be easy enough to make this work on other cell phone models. The project is clean and works well but we estimate the cost of the parts to be between $250-300, making it out of reach for those who don’t have a specific need for these types of measurements. This is especially true for paragliders who have much less expensive options available to them.
[Thanks Carl-Emil]