Category Archives: Education

Real Managers Know About Trust

bestboss__largeI was reading an interesting post about first jobs and the headline Good Bosses Are Key immediately gave me a flash back to my first “real job”.

I had gone through a year of programming school to which ended with a three month internship at a small company.

I turned up for the first day feeling, frankly, a little cock sure of myself.  That subsided quickly.

My first task was debugging a program used to calculate rent on properties and had been written by a programmer that was no longer with the company. After hours of pouring over the code I not only couldn’t figure out why it was going wrong, I couldn’t even figure out how it could ever have worked at all!

sadwalkI left that first day with my tail between my legs and thinking I had made a huge mistake. But I turned up for work the next day and tried again…and the next…laying out pages of hand written sheets showing variable values.

After a couple of weeks I went to my boss and meekly suggested that the way to solve the problem was to completely rewrite the core calculation routine. I was convinced he would laugh me out of the office.  Instead he asked how long it would take and I told him two weeks.

Put yourself in his shoes.  You have an 18 year old in front of you that you have only known for two weeks.  He’s fresh from college and telling you that the solution to your problem is to completely rewrite the system core which written by an experienced programmer.  What would you do?

My manager looked me in the eye, picked up the phone, called the biggest (and most vocal) client we had and told him we would have a solution in two weeks. Then told me I’d better get started.

Holy Cow!  The game was now truly afoot.

I’ll cut to the chase.  I worked night and day to make that deadline as there was no way I was going to let down the man that just put it all on the line.  We installed the upgrade and…IT WORKED!

I look back on that now and realize that was a formative moment for me.  That was when I made the jump from boy to man, and it has affected my career ever since.  But how many managers today would dare to take such a risk?

Sadly, today, managers are almost totally risk averse.  Failure is not something that is tolerated, and that is leading us to a world where opportunities for growth are giving way to excuses and playing it safe.

Personal growth happens when you step outside your comfort zone and we are punishing people if they do that. In doing so we are stunting the growth of our employees.  

I learned so much from my first boss that I will never be able to adequately repay him.  The company only lasted a few years (there were other bigger issues) but the three years I spent there were some of the happiest and most formative of my life.  All I can say is…MP…Thanks for taking the risk.

126-2669_IMG

MP hanging with my daughter

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Drones: One year on

On January 2nd this year I took a flight over my neighbors house using a store bought drone (Phantom FC40) and a GoPro camera that arrived as a Christmas present.  I was very happy with the quadcopter and the footage I took.  Then, about a week later, I sunk the whole kit into a lake never to be seen again.

At the time I was pretty upset with myself – I made a rookie mistake and paid for it badly.  But I also reasoned that since I had enjoyed modifying the FC40 I should try my hand at building drones instead of buying them.

One year later and I’ve come a long way learning everything from soldering to PID tuning (don’t ask).

I eventually built two different copters, a quadcopter and then a hexacopter, although it feels much more than that because each of those has been built, rebuilt and upgraded numerous times.  Here’s a quick comparison:

 

DJI Phantom FC40 F450 Quadcopter F550 Hexacopter
 IMG_1482.JPG  _MG_4923.jpg  20151122_093203.jpg
Transmitter Range  800m 2,000m
 Flight Modes
  • GPS Hold
  • Altitude Hold
  • RTL
  •  GPS Hold (slow and fast)
  • Altitude hold
  • RTL
  • Automatic (programmed)
  • Land
  • Guided (click on moving map)
  • Manual
  • Acrobatic
  • Follow me
  • Circle
  • Mapping
Speed 22mph ~35mph ~55mph
Size 330mm 450mm 550mm
Real Time Telemetry No Yes Yes
Moving map No Yes Yes
Gimbal 2D 2D 3D
Camera Control Manual Manual or Fully Automated Point Of Interest Lock
Flight Time 9 Minutes 18 Minutes 15 Minutes

 

But probably the best way to show the difference is to compare two videos taken one year apart.  The video on the bottom was from a year ago with the Phantom. It took two separate 9 minutes flights and was then edited to keep only the best parts.  The video on the top was taken in one shot, no editing and took less than 3 minutes to complete from take off to the fully automatic landing.

In fact this year’s video even made it into the local news, and you can find the full version here.

I’ve learned a huge amount that past year, gained some great friends and had a blast doing this, particularly as my #1 son and daughter were very involved in the build of both machines.

Where do we go from here?  

The drone market is in a phase now where digital cameras were 10 years ago.  Their capabilities are increasing exponentially while prices are plummeting.  Even with how far I have come even the cheapest DJI Phantom 3 would outperform my hex in almost every way and these can now be had starting at under $700.  Just a year ago something with that capability would have cost nearly three times that amount!

For me to build the equivalent of a Phantom 3 Standard would cost around $450 in parts alone, and that is if I use cheap parts sourced from China that would need a lot of time to set up properly.  

Will I still build?  I think the days of building from scratch are over, it just doesn’t make economic sense anymore.  But I will continue to improve the ones I have as a way to learn and experiment.  There’s also talk of teaching kids how to build them as part of a maker space project and that is something I would really enjoy doing.

In the meantime, if you are thinking of getting someone a drone for Christmas, or have one and need questions answered…fire away!

 

 

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Did I Hear That Right?

Mandatory training in America is usually there to protect the company rather than teach you something new.  But a number of years ago I attended a class that taught a life lesson I have tried to pay attention to every day since.

This particular class was entitled “Diversity Training” and I expected the usual loss of an hour of my life while someone explained things that were (or should be) patently obvious to anyone with an IQ above that of a hammer.

flipWe knew something was up when we arrived to find a room with no tables or chairs, just flip charts and some pens in each corner.

The instructor got down to business by dividing us into groups and giving each group a piece of paper.  Our instructions were simple: Read the paper, listen to the scenarios that she would read out and then write down our thoughts on the flip chart we had.  

After several scenarios were read and thoughts written we compared the results.

The first scenario she read was as follows:

“The person on your sheet has just brought in the biggest account the company has ever had.”

The flip charts were arranged such that the groups could not see each others answers so imagine our surprise when we found the following results:

Group 1

Group 2

  • Fantastic!
  • What a guy!
  • We should take him out for a drink to celebrate
  • Give him a big bonus!
  • Give him a promotion!
  • I’d like to shake his hand
  • He got lucky
  • Even a blind squirrel finds a nut once in a while
  • Probably stole the account from someone else and didn’t give credit
  • If he can do it then anyone can

Huh?  Same question, read by the same person at the same time.  What happened?

The difference was what was on the piece of paper.  

Group 1 had a paper that read “The person you are about to hear about is well liked, hard working, intelligent and expected to go places.  Everyone expects that he is on the fast track to senior management.

Group 2, by contrast, had a paper that read “The person you are about to hear about is lazy, not particularly intelligent, never helps anyone out and is fully expected to be let go in the near future.

There were more scenarios such as the person losing the biggest account (Group 1 commiserated while Group 2 wanted him fired) but I think you get the picture.  The message was the same, but what people heard was completely altered by what they personally brought to the table.

This is human nature and it is very hard, if not impossible, to avoid infecting what you hear with your own biases, but I still try.  More importantly I try hard to keep my thoughts about someones faults to myself to avoid infecting others.  I can’t say I am always successful, but at least I try.

So the next time you hear something that you feel negative about take a moment to think about it.  Are you getting the real message, or the message you wanted to hear?  

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Building an F450 quadcopter – Removing the Wobble

With plenty of flight modes now available it was time to address the wobble I noticed on the first flight. 

Some Googling pointed to the most likely candidate for wobble and the copter sounding “angry” was that the P-gain was too high.  I don’t know what that means but I figured that this would be easy to take care of.  Take off in Altitude Hold, run Auto Tune and, voilà!  Problem solved.  

Unfortunately it turned out to be more difficult than that.

With my new-found knowledge of how to set up the controller I was able to configure one of the options to be Altitude Hold, and set up a switch to start Auto Tune and I set off to get it done.

It was a somewhat windy day so I chose a local school (it was Saturday) that had a nice square protected on three side by buildings thinking this would give me some protection.

I took off in stabilize, stopped at about 15′ and switched to altitude hold.  Immediately the quad shot up about another 20′.  It was now high enough that it was no longer protected by the low buildings and it started to drift fast!  I immediately pressed down on the throttle and it came down, but much slower than I hoped.  I switched back to stabilize as it got near the ground and it dropped very fast, bounced once and landed up side down.  Bummer!

A quick check and things seemed OK, or so I thought.

I sent her back up again and exactly the same thing happened.  This time I had left myself more room and tried to leave it in alt. hold, but now it was really acting oddly.  Pressing the lever to make it go forwards caused it to climb more each time and, with the wind, it was now high up and drifting over the top of the school buildings.  I was convinced it was going to end up on the roof and, in a last desperate act, pushed forwards all the way.  Finally it responded and shot away from the school.  Bringing it down again was, once again, very slow and with the lever all the way down I switched back to stabilize.  Unfortunately the throttle all the way down in stabilize basically means turn the props off and the quad drop out from the sky like a brick.

Time for some self-analysis and to find the culprit of the problems with altitude hold.

vibrationMore Googling revealed that altitude hold issues are often caused by vibration.  Fortunately the APM captures logs every time you fly and I was able to download those into Mission Planner and (after some experimentation) view the vibration logs. This proved to me that this wasn’t the problem. 

flight_mapIt also showed me that this little APM flight controller is super cool. If you have time it is well worth looking into the logs and what they can tell you.  You can even upload these into Goole Earth and get a 3D picture of your flights complete with color coding to show you which flight mode you were in.  Nice!!

Since Auto Tune was off the cards until I could figure out what was wrong with the altitude hold it was time to start asking for help.  Someone on the Quadcopters group provided me with the settings they had that worked and, in comparing those, I noticed that a TRIM_THROTTLE value of 33% seemed much too low compared with his settings.  This is APM’s estimate of the throttle required to maintain a level hover calculated automatically from the pilot’s throttle input while in stabilize mode.  Mine was way too low and actually outside of the 40-60% that is the mid point for altitude hold.

On a hunch that I hadn’t flown in stabilize mode enough for it to get a good reading I went into the back yard and ran through two fully charged batteries doing nothing but trying to keep it in place in stabilize.  Then it was off to a large open area and, voilà!  Alt hold was now working without any crazy behavior!  I was losing altitude on long runs, but for the most part it was well-behaved.  Checking later I found the  TRIM_THROTTLE value of was now a much more sensible 43%.

While working on identifying the Alt hold issue I had also found out that I could assign a knob on the controller to Ch 6, and set that up such that I could adjust the P-Gains while in flight.  I did that, used the knob to back off the Rate Roll and Rate Pitch P gains until it calmed down.  When I got home I found out I had dropped from .15 to .13 so I locked those values in and saved the configuration file to my hard drive as a baseline.

Oh, and for the record, let me just say that testing altitude hold while tying the quad down to a table gives the barometer false readings and doesn’t work, so don’t try this 🙂

But what about Auto Tune?  Now that I had a copter that could stay in the air I went out the next day with a fully charged battery and ran it.  It is very odd watching your quad do it’s dance with no input from you, but it finished without incident.  The results?  Terrible!  It was back to being funky again and very difficult to control.  The good news – remember above when I said I saved my working results as a baseline?  Well, I just restored those.  My old developer habits still keep me honest.

I still have a problem with the craft losing altitude when flying forwards.  I think I might have improved that by stuffing the APM with cotton wool, since I had lost the little piece of foam.  Sadly that was three weeks ago and I have not had a chance to fly since then when it wasn’t raining, snowing or blowing 35mph winds.  I’ll keep you posted on how that goes.

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Building an F450 quadcopter – Setting up Flight Modes

After the first flight there were a couple of obvious items that needed to be addressed.  More flight modes and getting rid of the wobble.

First the flight modes.  

I had only figured out how to set up the controller to allow for two different flight modes (stabilze and altitude hold).  With so many modes available on the APM this seemed like a shame.  It took a while but by carefully following the instructions on this page I was finally able to get myself up to six flight modes by using a combination of 2-way and 3-way switches.

flight modesAlong the way I had an epiphany that the controller sends out frequencies (or something that can be counted) and that the APM looks for values from the different input channels being in ranges (because it isn’t exact).  So a value between 1,231 and 1,360 (for example) can be assigned to a particular flight mode.

Great!  A mystery solved.  Now all those calibration movements make sense.

Not only did I manage to assign the six flight modes, but on the extended tuning I was able to assign Channel 7 to a switch on my controller that would automatically tell the quad to land.  This has been a real life saver because even when it starts going crazy, switching to land will calm it down and bring it down to Earth better than I can do.  

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Building an F450 quadcopter – After the Build

flight_mapAfter our successful first flight it quickly became obvious that having a machine that can fly is just the beginning.  In the weeks that followed there were a number of change, crashes, and not an insignificant number of problems some of which are still not yet solved.

All of this occasionally has me wondering why I decided to build a quad copter instead of just plunking down money and to answer that we need to go back about 10 years to when I took my first tentative steps into the world of websites.  Back then I started a web small business with a friend and the venture lasted about two years before closing it’s doors.

Was I sad that the company closed?  No!  In those two years I had learned far more by doing than I could have learned in the same time at school, and the same applies here.

Each problem is a puzzle to be solved, an opportunity to learn and, as I have discovered, a great way to make new friends.  As I learn I like to give back to the community that helped me when I can and, as such, I plan to memorialize much of my learning here in small posts dealing with very specific subjects.  Much will not be of interest to people, but my hope is that one day someone will benefit from the time it took to put this together.

Pay it forward!

 

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Building an F450 Quadcopter – Day 7 – A very low first flight

Having seen one too many videos where the quad flips over on takeoff I was understandably nervous about trying our new baby out.  It seemed that at every turn there were little details that needed to be checked and re-checked.

For example, we checked the rotation of the motors and S. then fitted the props according to their direction.

APM RotationLater I noticed that we had the exact opposite of what was shown on the APM website.  Our props should have looked like this but were not. So, when S. wasn’t looking, I switched them.  

Fortunately I had woken up that morning with an idea that would allow the quad to fly a little, but not enough to flip over if things go wrong.  It didn’t take long before I had it lashed to our table tennis table and we were ready to try her out!

With S. videoing the first test was a spectacular non-event.  I powered up and slowly increased the throttle until full throttle was reached.  We had plenty of noise but absolutely no lift at all!  Then I realized.  S. had been right all along and I had switched the props which were now pushing it DOWN!

A quick switch of the props and we were back in business.  This is when I thanked my lucky stars that I didn’t trust myself to try it without a safety net.  Every time it lifted up it would go wild and try to flip over.  Fortunately the string kept it in place, but it was all over the place and none of the controls made any sense!  See for yourself!

I checked things over again and realized my mistake.  I had plugged the motors into the APM board with output 1 going to motor 1, output 2 going to motor 2 etc. in a clockwise pattern.  However, as you can see from the diagram above, the ONLY motor I got right was number 1!

Switching the connections on the flight controller had us finally up and running.  It now behaved, didn’t try to flip anymore, and I could lift it up and move it backwards, forwards, left and right.  Forward and backwards was reversed because for some reason the APM sets it up to expect the ELE control to be backwards.  No problem, it just took 30 seconds to change that on the transmitter.

While it seemed to be working it was very twitchy and super sensitive to the controls – nothing like my Phantom which was very docile.  

I posted the video on the quadcopters FB page and our good Samaritan made a comment about how twitchy it seemed. I then found out that the latest version of the Mission Planner software has a sliding scale from 1 to 100 where the higher the number the faster it responds.  Guess where mine was set…yup…100!  I backed that off to 80 which seems to have calmed things down nicely without taking all the fun out of it.

basicOne last thing.  Remember I said that my motors were the exact opposite of the picture on the APM website?  I was under the assumption that it didn’t matter as long as they the same rotation was on the opposite corners.  Turns out that is incorrect and that not having it the right way around is going to cause problems with yaw (spinning on its axis), and possibly more.  So, after some gentle teasing by my friends about not knowing how to fit props, I switched the bullet connectors so that they now all spin the right way.

After all those changes I put it back on the “test rig” and what a difference!  It was beautifully smooth and easy to control.  See for yourself.

So, that it is.  There are still many tweaks to do, such as setting up the battery failsafe and adding LED lights, but really the next big step is to wait for a clear day and take her out.  I can’t wait!!

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