Adruino Controlled Brushless Motor Test Stand

13. May 2014 11:49 by outbackuav in Hardware, Posts

I've tested a few motors using my HobbyKing 7-in-one watt meter to learn the whole which prop/ESC/motor/battery thing.

There's some good videos on this topic notably Ed from Experimental Airlines who did and exhaustive study with some kitchen scales and a watt meter.

Being lazy I wanted to avoid the onerous task of actually writing down numbers and enlist the Arduino to do it for me.

Having done a few Arduino projects I thought an automated test stand might be fun to try.  I'd never output PPM from an Arduino or read from current sensor but how hard could it be?

The main difficulty was outputting the right values for arming, you need to go from something the ESC recognises as low throttle, to high, then back to low.  I tried a few things to work it out including hooking up the ESC to my servo tester to see what the PPM values should be.

Main Components

I did 4 years of woodwork at school so it should have been better than this


Just an Uno I had lying around, no special shields but I have a proto shield that I might use to tidy up things and get rid of the breadboard.

Current sensor

Spare one from my Bixler build - from RCTimer I think.

Thrust sensor

I had an old Phidgets force sensor but I discovered it isn't accurate.  It's intended to just sense force, not tell you how much.  I ordered a some sort of strain gauge on eBay and it never arrived - that's $3.56 I'll never see again.  I have an old kitchen scale that I'm planning to tear down and use if I can find a measurable analogue voltage on it.

In the meantime I've used a spring from and old desk lamp and a slider pot to give a fairly good thrust measurement.  I calibrated it by hanging a cans of beans from it - isn't science wonderful!

Temperature sensor (eventually)

Pointed at the motor to record heating.  This could be good for endurance testing but a high amperage supply from the mains might be better to eliminate battery fade from the results.

.Net Application / Firmata

After feeling a bit confined by the Adruino code limitations and slowish code upload speeds I discovered this excellent bit of code called Firmata which allows you to control a connected Arduino from, in my case, a C# application running on a PC.  I was able to do a lot more (e.g. funky-town user interface including graphs) and luxuriate in object-oriented goodness.

I'm sure that once I learn a bit more about Arduino scripting (or is it sketching?)  I'll be able to structure my code a bit better an dpossibly use a little LED display shield although I do like the graphs.  I might have to investigate using one of those OLED shilds that have the resolution for graphs.

Basically Firmata has a library/DLL that you can call to do inouts and outputs on the Arduino.  Firmata handles the rest - as far as your .Net application is concerned the action is happening locally.

A solution in Visual Studio runs the motor and record the results.  It arms the ESC then steps up the motor incrementally and records the current, voltage, thrust and one day the motor temperature at each step.  Gunna get to grips with GitHub so the code is available.

User interface


The Arduino and breadboard, the breadboard isn't essential, just convenient for connecting the test stand.

Things to Do

  • Make a smaller, neater frame
  • Make a prop guard
  • Do a video
  • Clean up wiring, make Arduino shield
  • Make quick release system for motor
  • Upload the code
  • Spreadsheet creation, Excel, Google Docs, comparison site
  • Vibration sensor?


  • Safety first!   Either make a prop guard or wear eye protection.


(Mostly) Aussie Heros

7. May 2014 21:39 by outbackuav in Posts, Videos

I got interested in the whole FPV thing about 4 years ago when I stumbled on a video of a guy sitting on the roof of a classic northern New South Wales hippy shack.  It was shot from what I now know to be a multicopter and it blew me away.  I've lost the link sadly.

Since it was a home grown vid that got me into this I thought I'd do a post of some of the prominent locals in the scene.

In no particular order:


Thomas and his Dad Paul live in Melbourne and do a great job of showing off FPV flying.  The frequency of new videos has slowed a bit but I think Thomas' school work might be the reason.  Either way quality before quantity!


If Jamie Oliver was reviewing Monjon's videos he'd say "blummin' Gorgeous!" - super scenery in the Kimberly region of Western Australia.  Living in inner-inner-Sydney I'm very jealous of all that flying space.


From what I can tell Juz is a ranger in Victoria who is a tester with the Revo or Revolution flight controller.  He really puts his copters under pressure.  I'm not a copter enthusiast (not rich enough!) but his videos are great and non-Aussies seem to love that he often gets a mob or 'roos into shot.


A keen slope soarer from my old home state of South Australia who makes all sorts of vids.


And the The Russell Crowe Honorary Strayan Award goes to:

Bruce Simpson of RCModelReviews and XJet fame

OK OK he's a proud Kiwi but we have a long history of passing off clever Kiwis as our own!

and now, as Bruce says, it's time for me to go "beck to the binch"!

Video of the Week

7. May 2014 21:21 by outbackuav in

One of my favourite video makers is RCSchim from Austria.  He has a great laid back manner and flies around some amazing scenery, this time in northern Italy.

Sadly on this flight he lost his quad though.  It was attacked by an eagle.  To make it worse his ground recorder wasn't running and the quad is black.

6 Tools I Wouldn't Be Without

6. May 2014 20:08 by outbackuav in Posts

1. Tweezers

Super fine Japanese tweezers from eBay, I have straight and curved but the curved ones don't have much grip.  Very useful for grabbing stuff inside small fuselages and wings.

2. Chemist Glasses

If you don't need them now, you'll need them one day!  I used to used a magnifying glass on the top of a set of helping hands but the glasses are much easier.

3. Temperature Controlled Soldering Iron

I replaced my basic 40 watt unregulated with a Chinese temperature-controlled iron with a digital display.  It was very cheap (sorry Haako!) but it does a fine job.  I bought a set of tips that make any job a lot easier.  I used to dread soldering now I've soldered new wires on to servos and even added resistors inside a servo to make it sweep 180 degrees.

4. Servo Connector Crimper

Free yourself from the tyranny of servo extension cables and connectors in inconvenient places.  Crimping is easy and makes much neater planes.

5. Combination Watt Meter, Servo Tester, Battery Checker

I've got a little HobbyKing 6 in 1 unit that is very useful for understanding what current I'm using, testing servos and peeking insode batteries.

6. Half Decent Muiltimeter

My first one was $4.99 (can you tell I'm cheap?).  Finally upgraded to a new one and it has automatic voltage ranging and best of all, an audible continuity tester - very useful when you've got into some contortion to put the probes on and then realise you can't see the screen.

Go Trent!

6. May 2014 13:22 by outbackuav in


In my extensive YouTube watching experience I’ve seen a lot of very enthusiastic and energetic people in the RC world. There’s Josh Bixler, Glassdogangle, DemonDriver, Jeremiah and Alex from Stone Blue Airlines just off the top of my head but I can’t think of any who pack more punch than Trent from MyGeekShow.


In the last couple of years year he’s gone from newbie to attempting one of the greatest feats ever tried in the RC world.  He’s going to try and fly one of his Raptor 140 flying wings across the United States from San Diego to South Carolina(?) a distance of around 4,000km.


I’ve taken a small sponsorship via Indiegogo of one of the wing panel ads that will proudly wear the OutbackUAV logo that I laboured over for a good 3 or 4 minutes...


Even if he doesn’t make it it will be epic.  It's worth the tiny sponsorship just to see him try.  Trent’s the kind of guy that is pretty unstoppable despite having a full-time job (and we know Americans don’t get much holiday/vacation leave) a wife and family plus other commitments. 



I'd love to try the same thing here in Ostraya, maybe Shark Bay to Byron Bay?  It probably wouldn't be as interesting because as anyone who's crossed this wide brown land knows that it's very wide and very brown.  It's about 4,000km as the crow flies, about the same as Trent's route but there's basically no East-West roads across Australia 'through the middle' unless you have two 4-wheel drives, a lot of water and fuel and a Flying Doctor radio.




I'll be in Greece at the time but I'll try and get a SIM for my phone so I can see Trent give it a red-hot go.


Welcome To My Blog!

26. November 2013 13:07 by outbackuav in

Hi, I'm dipping my toe into the blogging caper!

I hope I can share some of the things I've learned in RC.