Sunday, April 10, 2011

Getting Started

I decided to build an airplane about 15 years ago. A lot has changed since then. The idea of a glass panel, back then was almost unthinkable for any reasonable amount of money. Today, a glass panel is pretty common. There was one company building a complete graphical engine monitor, and a couple doing bits and pieces. Today there are dozens.

Why should I do this...

I have a different idea. I think the ones out there are too darn expensive. Sure the bill of materials they have chosen probably necessitates the price. Sunlight readable LCD displays are expensive, along with all the software and reliability that is needed in the box. Switches, cases and connectors are special for use in an aircraft.

Airplanes are different than cars. High speed and constant vibration are going to cause issues, it is hard to install them. Installation, and building are two different things. Installation issues are the same, almost, no matter what unit is purchased.

My idea is different. I like the idea of component equipment. Have a display box, a data access box, and maybe eventually have an air data computer. Using components, I can upgrade one component at a time, and not have to bother the whole system. If you have a integrated nave system (car or airplane) how many times have you said, I wish this worked like my phone (or had some other new feature).

Components are more expensive...

For stereos, you can buy a boombox or other integrated stereo for far less than component stereo equipment. That is reality. Components are pretty standard in home audio world. In the computer world, things are rapidly becoming standard, but you can't quite plug and play this and that. Communication standards are available, and there are plenty of standards to choose from.

My design is hopefully, going to allow me to upgrade parts that I feel need upgrading without destroying what I have working.

I've been working on this for a while...

About 5 years ago, I started prototyping something. I started with an OEM AT mega board and a prototype board. I had connectors for thermocouples, for CHT and EGT probes, and some other A/D converter connections for the oil pressure and temperature. I had a serial output, that I could connect to a laptop, or a Zaurus mobile internet device, and a GPS board that I started playing with. I got distracted with the GPS board, and never quite started messing more with the engine monitor.

During the last couple years, I knew enough about GPS by now to get a job working on RNP satellite monitoring. That was a good benefit, but now I want to go further and do real live avionics type work.

My idea...

The idea is to stick with the AT mega, but use a COTs board, an Arduino board. An Arduino Mega board has 16 A/D converters, and many digital IO pins. The analog inputs will be:
  1. 4 CHT probes
  2. 4 EGT probes
  3. Oil Temp
  4. Oil Pressure
  5. Fuel Pressure
  6. Fuel Level
  7. OAT
  8. Manifold Pressure
Digital inputs may include fuel flow, engine RPM, and various status switches (trip start, etc).

For a display, I was thinking of using one of my phones or mobile internet devices. They are inexpensive (I've already paid for 'em). They have touch screens, and pretty good graphics. If this whole thing works, I would like to get a tablet computer for this.

For communications from the Arduino to the display, I had considered using USB, since almost everything uses that, but then I found a project that allows the Arduino to talk bluetooth to an Android phone. The perfect place to start.

Where am I today???

I've ordered the Arduino Mega board, I've gone through my old notes about my project, and I've downloaded the Arduino software. I've read the hello world example (blinky), and tutorials 1-85 or so (not really, maybe 1-8). We will just have to see where things go, and how far I get.

How is all this going to work?

I am not really sure. I've never blogged before. I thought it a good way to get my thoughts out there, and allow someone to repeat my work, if it is mildly successful. If it a wretched failure, well, there may still be stuff to learn.

I have lots to do in my real life, this will only be a hobby. If I don't write anything for weeks, give me a nudge, I might be doing something useful, and unable to write. If I don't write for months, maybe the project will be dead.

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