Hi, I am new to the Arduino world, having just received my first starter kit today.  I jumped into this for basic learning and fun, but I also have a goal of offering fellow homebuilt and ultralight aircraft enthusiasts an open source solution for Arduino-based gauges.

I am trying to come up with a simple modular system that could be adapted for different gauges:  altimeter/vertical speed to start, then maybe airspeed indicator, and finally things like compass, an accelerometer for turn/bank indications and a G meter.  By a modular system I mean one simple display format, that could be used unchanged for most if not all of the functions above, ideally combining both a numeric indication and an analog graphic.  Only the code and the sensors and maybe the colors would change.

One option I have come up with is a Tinyduino with a stock or custom sensor Tinyshield, a Matrix LED Tinyshield, a 4-digit 7-segment or alphanumeric display in the same color, a backup battery and voltage regulator, and a couple of buttons or maybe a rotary encoder with push-to-select on the front for settings and adjustments.  The matrix would allow each gauge to show both a numerical value and an analog indication at a glance.  The altimeter would show a numerical value for altitude and an larger or smaller up or down arrow for climb or descent.  The compass would show a numerical value for heading and an arrow indicating north and so on for the other gauges.

My questions for this group are--does this sound like something within the processing power of a Tinyduino.  I have lots to learn, I know, but are there any obvious pitfalls or constraints that I am overlooking?

Thanks and regards,

Matthew

If you could get the sensors into the TinyDuino, this is very possible and potentially quite easy. Even the TinyScreen would be a good display option as it is a very bright OLED -- you would just need to make to write the software to make it readable at a distance.

Thanks, I think a few of the existing sensors could be used and others could be added to one of the standard TinyShield proto boards.  I am not convinced that the TinyScreen would be a good fit, as it's awfully small and I am not sure it would remain readable in direct sunlight. I am pretty sure that the LED matrix and a 7-segment or alphanumeric LED module behind a clear or translucent anti-glare cover would still be readable in direct sunlight.

If you could get the sensors into the TinyDuino, this is very possible and potentially quite easy. Even the TinyScreen would be a good display option as it is a very bright OLED -- you would just need to make to write the software to make it readable at a distance.

Thanks, I think a few of the existing sensors could be used and others could be added to one of the standard TinyShield proto boards.  I am not convinced that the TinyScreen would be a good fit, as it's awfully small and I am not sure it would remain readable in direct sunlight. I am pretty sure that the LED matrix and a 7-segment or alphanumeric LED module behind a clear or translucent anti-glare cover would still be readable in direct sunlight.

I think a sensor input and display output is the best way to learn Arduino. It's practical, you will see the results quickly, and you will learn to tweak your code to get the output you need.

Accelerometer output, outside of tilt/etc, is very hard to process if you are looking to create some sort of INS, get a feet per minute output, etc. Still, I have experimented with accelerometers on planes before, so a false horizon is possible and an uncalibrated feet per minute gauge should be very possible.

There are libraries out there though that have been used in UAV projects would really be a big help in your case. 

Sounds like you could cover most of the desired readings with the Tinyduino 9-axis IMU and the Tinyscreen. The Tinyscreen even has four buttons in which you could use to rotate through the display readings. The screen is quite legible in direct and low-lighting. The Tinyduino does have enough processing power for it. I use Tinyduinos for flight and sensor data on my quadcopters. I have it write data to an SD card instead of viewing it real time. However, they have the long range 433 MHz radio shields now. So you could collect the data from one Tinyduino on the aircraft and send it to a separate Tinyduino with display so you can clip the display where ever you desire.
 

Thanks, guys, I am not looking to do an automatic horizon, autopilot or anything so complex, just simple, individual instruments.  The existing compass sensor should work fine as is, the accelerometer for turn coordinator and G meter, and I'd need a single pressure sensor for alt/vertical speed and a dual one for airspeed.

After looking more closely at the Tinyshield options, I have a few more thoughts....

• The edge LED arc shield is interesting, but I'd need some sort of reflector ring to direct the light forward, and for some applications like a compass you really need 360 degrees.  Also, the connector is on the wrong side (female on front vs. male on back) if the LED are to be at the front of the stack.
• The circle edge LED is also nice and gives 360 degrees but it would also need a reflector ring and odd choice of 21 total LEDs makes it pretty much impossible to have symmetrical indication in all directions.
• The matrix LED shield is promising, but again the odd choice of a 6x9 matrix makes it more difficult to have symmetrical indications, though I think there are probably enough to get by.

Has anyone messed around with reflector rings to get direct the light from the edge LEDs towards the front?  Also, if anyone has any video of the Tinyshield LED matrix in action I'd love to see it.

Cheers,

Matthew

We did buy some weird circular LED screens for making a programmable automotive gauge, but never had time to move forward with it.  Now that we have more sensor boards I think we need to revisit it.

do they make a Tiny air speed sensor? Last time I saw one, it was pretty big.