# Arduino-Based Instruments?

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#### BoeveP51

##### Well-Known Member
Supporting Member
I used the Arduino for my flap positioning monitor. used a slide resistor to monitor position and feedback to Arduino. A 10 bar LED for indicating.

Used the resistor in the servo as the position source for my radiator door positioning. Display was a simple 10 bar LED. Both work really well.

#### jandetlefsen

##### Well-Known Member
Supporting Member
I used the Arduino for my flap positioning monitor. used a slide resistor to monitor position and feedback to Arduino. A 10 bar LED for indicating.

Used the resistor in the servo as the position source for my radiator door positioning. Display was a simple 10 bar LED. Both work really well.

This is what i want to do. How did you do the power supply? Did you use an external voltage regulator or just hook it up? I've read that if you are constantly over 12 volt the onboard regulator will get quite hot. Hoping to bet my hands on a huvver board but looks like they aren't for sale currently.

#### Geraldc

##### Well-Known Member
I used the Arduino for my flap positioning monitor. used a slide resistor to monitor position and feedback to Arduino. A 10 bar LED for indicating.

Used the resistor in the servo as the position source for my radiator door positioning. Display was a simple 10 bar LED. Both work really well.
You can buy a 10 led display board with lm3914 driver chip that reads directly off a slide resistor and no arduino needed.

#### BoeveP51

##### Well-Known Member
Supporting Member
This is what i want to do. How did you do the power supply? Did you use an external voltage regulator or just hook it up? I've read that if you are constantly over 12 volt the onboard regulator will get quite hot. Hoping to bet my hands on a huvver board but looks like they aren't for sale currently.
I found a 5V regulator/buck converter (whatever you call it) to power the Arduino and sense line. Works great. Have not had any issues.

#### rv7charlie

##### Well-Known Member
Supporting Member
Those 3914 based LED ladder displays are available from many sources. Here's an ebay link to LED VU meter. Note that the VU meters *may* have a logarithmic measurement curve;  check to be sure that it's 3914 based and not 3915 based. (Thanks to Bill Higdon for the reminder.)

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#### Bill-Higdon

##### Well-Known Member
Those 3914 based LED ladder displays are available from many sources. Here's an ebay link to LED VU meter. Note that the VU meters *may* have a logarithmic measurement curve, but the circuit can be modified to show either log or linear voltage measurement.
That'd be a LM3915

#### rv7charlie

##### Well-Known Member
Supporting Member
That'd be a LM3915
Right. It's been >30 years since I played around with them I forgot that there were separate part numbers. Earlier post corrected.

#### qchen98

##### Well-Known Member
LM3915 is quite complicated and frankly outdated.

A more modern solution would be some RGB led with WS2812 chips. It only takes one data line from the Arduino, however you can control each LED's color and brightness individually.

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• 1642467815137.png
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#### Geraldc

##### Well-Known Member
An description of the LM3914 chips here .
.
For a position indicator using a slide pot you might need to add a voltage regulator to allow for supply voltage fluctuations.

#### rv7charlie

##### Well-Known Member
Supporting Member
LM3915 is quite complicated and frankly outdated
Really? More complicated than hooking up power, ground, and input? How is that quite complicated, compared to needing to add an arduino, plus programming? If you already need the arduino for something else, the WS2812 would be fine, but for standalone, 'better is the enemy of good enough'.

#### jandetlefsen

##### Well-Known Member
Supporting Member
A more modern solution would be some RGB led with WS2812 chips. It only takes one data line from the Arduino, however you can control each LED's color and brightness individually.

Depends what package size you want your LEDs in. They make those 10 element bar graphs with red/green LEDs in a single resin casting for $5 (1). Hard to beat in terms of space used on your panel. Plus you can wire them up to have the mid 2 LEDs in green and the rest in red to quickly find your neutral trim. This is what i plan to use 1) https://www.mouser.com/ProductDetail/Kingbright/DC10EGWA?qs=A4JqA0/c8XbEqEvTSANN5Q== #### qchen98 ##### Well-Known Member Depends what package size you want your LEDs in. They make those 10 element bar graphs with red/green LEDs in a single resin casting for$5 (1). Hard to beat in terms of space used on your panel. Plus you can wire them up to have the mid 2 LEDs in green and the rest in red to quickly find your neutral trim. This is what i plan to use

1) https://www.mouser.com/ProductDetail/Kingbright/DC10EGWA?qs=A4JqA0/c8XbEqEvTSANN5Q==

If are using an Arduino, you will still have to use an lm3915 to drive that led bar graph.

One of the drawback of the aforementioned combination is that you cannot easily change behavior of individual led - whereas you can do it quite easily with ws2812 or similar led with build-in chip.

All it takes is just one GPIO pin from the arduino. so you can daisy chain them together. Programming is also easy enough with the existing library.

You could configure the light strip that way :

Close to netural trim - one single green led lights moving up and down, showing the trim position
Forward trim positions - blue led lights up one by one from the buttom to the top
Aft trim positions - red led lights up one by one from the top to the buttom

Too much aft trim - ALL LED FLASHING RED - AT FULL BRIGHTNESS

#### jandetlefsen

##### Well-Known Member
Supporting Member
Yeah i'm aware of those LED strips but i was looking for something more compact. There are ways to use the small bars and have make them individually addressable with a different driver i.e

#### Geraldc

##### Well-Known Member
Time to get this topic back on track.

I was playing with a Newhaven display on an arduino and did a search for aviation applications and found this.

#### huVVer

##### Member
Time to get this topic back on track.

I was playing with a Newhaven display on an arduino and did a search for aviation applications and found this.

I use Newhaven 320x240 displays for the huVVer.tech display instruments, that are in production. I have not had any luck with the EVE displays for real-time (16 frames/second) processing, so I developed a graphical widget library (aka GaugeWidgets) that can use any of the direct-drive displays supported by Bodmer's awesome TFT_eSPI library.

The NHD displays have been trouble free, except for their susceptibility to ESD, which I fixed in hardware. They are also (apparently) domestically sourced.

Cheers, Vern
Vx Aviation/huVVer.tech

#### huVVer

##### Member
And now for something completely different....
Slightly off-topic, but here's the Arduino connection: The huVVer-AVI instruments provide stereo audio for alarms and indications. Many (if not most) aircraft have mono audio systems, or the stereo inputs are set up for music and are automatically muted with comms traffic.

Responding to a request from the OnSpeed team, I am introducing a new opens-source (hardware) audio mixer (the AMX-10A), based on the popular AMX family that was first introduced 15 years ago. This mixer will be used for retrofitting OnSpeed systems into existing aircraft. It will be production ready this Spring. MakerPlane will be the commercial source.

Schematics will be published after production release.

Vern

Here's some info:

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• AMX-10A_install_A1.pdf
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#### huVVer

##### Member
Production run at MakerPlane. This stuff is real.

View attachment 119879

Software update for the huVVer-AVI instruments:
(March 1, 2022) Version 4.00 of the flight instrument library has been posted to huVVer-AVI Download – Vx Aviation & huVVer.tech In addition to graphics refinements, There are some new features:
- The Attitude Indicator now has selectable upset recovery arrows and markers at +/- 90 degrees to assist in accurate aerobatic manoeuvres.
- The System Configuration menu now allows the selection of serial ports for the data streaming input, including the USB port.
- Night operation has improved by providing more dimmer levels and a change to the dimmer function operation.

Some of these updates have been made to support the evolution of the OnSpeed energy display development.

Details are available in the QuickStart Guide on the site.

VV

#### Yellowhammer

##### Well-Known Member
Supporting Member
Have you had a look at this
it is Arduino based and I believe open source.

It is open source. Great Business!