Hardware and Software
The first generation tone generator is a small box with an Arduino Due computer that uses the AOA signal from Dynon DY-series or SkyView EFIS to generate the AOA tone for the pilot. The Dynon systems have a serial output which is connected to the Gen 1 box. The pilot either connects an aux headset input into the box directly or it plugs into an aux input in the intercom system. The Gen 1 box only works with a Dynon EFIS equipped with an AOA probe. The Gen 1 system uses inexpensive off-the-shelf components and can be assembled and installed by experimenters that have airplanes equipped with Dynon avionics that are familiar with basic electronics and small, prototyping processors.
Because our initial objective was simply to demonstrate the utility of using the aural AOA logic, we used an existing AOA signal. Initial flight test and follow on beta test of the Gen 1 system resulted in lots of good lessons learned, including the need for simplified, accurate calibration procedures, improved signal processing and accuracy of the angle of attack solution. The hardware design of the Gen 1 demonstration system is frozen. Gen 1 software is hosted and maintained on GitHub.com to allow for collaboration and download.
The Gen 2 ONSPEED design is completely self-contained and has on-board differential pressure, static and attitude sensors. It uses a Tensy 2 processor and has 32 MB of internal data recording capability. It has standard 1/4" OD quick-connect fittings for pitot, AOA and static inputs. It uses an advanced algorithm for measuring AOA that can be adapted to different types of differential pressure sensors. The processor also has excellent MIDI capability, allowing for a much more pleasant sounding tone and stereo capability for adding left/right acoustic cues.
The circuit has advanced capabilities for future growth including wireless interface.
Our current work is focused on validating the Gen 2 design and software. Instructions for experimenters familiar with electronics that wish to build there own hardware and integrate it into their airplanes are included in this section. Gen 2 software is maintained on GitHub.com for collaboration and download.