lidar based altimeter

[RV14_TD]

I'm thinking about building a lidar based altimeter, something similar to this thing but integrated with HDX, ideally showing the AGL as a widget on screen.
The one solution that comes to mind would be to convert digital output of lidar sensor into analogue and connect it to EMS, calibrate that input on the HDX side and display as EMS widget. Is there a better way to connect a digital input (lidar sensor) into HDX and display the data on screen?
Anyone here with a homebuilt radar altimeter?
@Dynon would you display in some form "radar altimeter" based AGL into PFD display?

PS. I'm aware that HDX displays AGL on map screen.

 

[Marc_J._Zeitlin]

So I use this:

SF11/C (100 m)

The SF11/C microLiDAR™ is a long-standing preferred above ground altitude sensor. With solid support from autopilot platforms, this 100m sensor has proven the test of time. *Included in the box: SF11/C LiDAR sensor, a communications cable, and a USB to micro-USB cable. Applications AGL (Altitude...

lightwarelidar.com

in an automatic landing gear extension circuit on my COZY MKIV. It's part of a circuit that will lower the LG if I'm >40 KIAS, <90 KIAS, <10% throttle, and <400 ft. AGL. I'm using it as a switch, but it does have an analog voltage output capability. So _IF_ the SV has the ability to allow you to build a custom widget that reads AGL from analog voltage, it would be relatively cheap to use this to do so. I suppose it would have better resolution than the terrain map in the Skyview, but now that AGL can be displayed on the map, I don't know what real advantage it would have.

I would have been happy to use the AGL output in the USB/Serial output stream instead of this device for my circuit, but sadly, for reasons that remain completely opaque, Dynon does not output AGL in the USB/Serial output stream, even though it can be displayed on the screen. I've requested this years ago, but...

 

[Rhino]

Guide for creating custom sensor definitions

What ever happened to the guide Dynon authored for creating your own custom sensor definitions? Seems to me that would still be a very handy document to have, even just for general principles. https://forum.flydynon.com/threads/making-your-own-ems-sensor-definitons.11796/post-70235

forum.flydynon.com

Several inputs are voltage based.

 

[Dynon]

I'm thinking about building a lidar based altimeter, something similar to this thing but integrated with HDX, ideally showing the AGL as a widget on screen.
The one solution that comes to mind would be to convert digital output of lidar sensor into analogue and connect it to EMS, calibrate that input on the HDX side and display as EMS widget. Is there a better way to connect a digital input (lidar sensor) into HDX and display the data on screen?
Anyone here with a homebuilt radar altimeter?
@Dynon would you display in some form "radar altimeter" based AGL into PFD display?

PS. I'm aware that HDX displays AGL on map screen.

There isn't a way to bring general purpose information onto the PFD. Custom EMS widgets are the only route I can think of here.

 

[Barry’s Phoenix]

Sorry - this is off-Dynon-topic, but: I have done some 'playing' with a prototype Lidar based height display. The first question is "what is your objective?" I don't need the 50,30,20 height calls like the Airbus, but what I wanted is some help learning the perect flare. I have a Phoenix motorglider which is a tail dragger with very poor visibility out the front when landing, and you have to land right on the stall/3-point attitude otherwise it bounces. So nailing a cross wind landing is a challenge.

My objective is to have a visual indication of height, just in the last 3 feet, so I can hold it at around 1 foot or less off the ground, but not touch. I didn't need the 100m range, so I used a TFMini Plus https://www.sparkfun.com/products/15179 which is also IP65. I believe it should be OK in full sunlight but have not tested it in midday flight. (Note the unit quoted above says it has autopilot integration but that is only for drones!)

For the display I really wanted something that can indicate in my peripheral view so I used a small colour LED bar display - a NeoPixel Stick with 8 colour LED, 50mm (2") long which I think is enough for a peripheral vision indication using the colour carefully. I can mount the strip up high just in view when looking out the side (Lindburgh reference). It is then driven with a small Arduino board.

I guess you could give an analogue output from the Arduino and setup a bar display on your EMS screen to do similar if it was visible enough in your peripheral vision.

My flying got interupted (Long story) so I have not had a chance to try it properly - only flown once and the display didn't stay in place...

 

[RV14_TD]

The goal is to improve situational awareness during night landings or in marginal weather. The Lidar SF11 device suggested by Marc would be a perfect fit, especially because, as I understand it would be possible to connect it directly to EMS to get AGL data into Dynon
@Marc_J._Zeitlin did you experiment with the analogue output of SF11?

 

[Marc_J._Zeitlin]

The goal is to improve situational awareness during night landings or in marginal weather. The Lidar SF11 device suggested by Marc would be a perfect fit, especially because, as I understand it would be possible to connect it directly to EMS to get AGL data into Dynon
@Marc_J._Zeitlin did you experiment with the analogue output of SF11?

Nope. I only use it as a switch for the landing gear circuitry.

But the Skyview can (if configured) now display AGL in the map INFO items, if you want it. Still doesn't output it into the serial stream, though, for unknown reasons. I don't know if the Skyview AGL display would be (or is) accurate enough to give flaring info during landing - I'll have to stare at it the next time I'm landing and see what it tells me. Since my ADAHRSs are about 2' above the ground, but the GPS accuracy has a 10 - 30 ft. tolerance band, I would only expect it to be good enough to get you to the runway, not on it during a flare. That's certainly what we discovered when I was working with a company doing autonomous aircraft work.

The SF11, on the other hand, could easily be calibrated with a position offset and give centimeter level info on distance above the runway.