Category Archives: Technology

The Clean Disruption of Energy and Transportation

Did you know that there was only one automobile in the 1900 New York City parade, and just 13 years later there was only one horse?

Seven years ago I predicted that self-driving cars would be the norm very soon.  But as Tony Seba correctly points out, it is the merging of different technologies that really bring innovation and disruption.

Combining self-driving, solar power, ride sharing and the amazing longevity of electric vehicles it seems clear that the future of transportation is about to undergo massive disruption.  And if Tony is correct, we are going to see major changes in just a few years!

This video is long…but well worth watching.

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Filed under Automobiles and motorcycles, Technology

Cutting the Cord – Two Years On

cutting-cableTwo years ago I was finally ticked off enough with the continually rising cost of cable TV and cut the cord.

I missed Formula 1, and watching Wimbledon and the US Open was problematic, but overall life was good.

Last week I finally (long overdue) decided to cancel the home phone because the only people using that were telemarketers.

The person I dealt with was (for once) knowledgeable and didn’t try to talk me out of it. Instead he put me on to a deal that included high speed internet (60mbps) AND basic TV channels.  All for a monthly price of just $54!

So, two years after cutting the cord the TV is now back…but now I pay just $54 a month instead of $200.  My wife has been happily watching Wimbledon, I watched F1 practice last night for the first time in 2 years, and we haven’t had a telemarketer call in a week!

What did we learn in the past two years?

Pick the right device.

roku-chromecast-vs-lead

We started by using a Chromecast because they were cheap ($35) and I believed that Google would be able to expand quickly.  To use the Chromecast you need to use an app on a phone or tablet and this caused a lot of frustration.

Want to back up 30 seconds to catch the line you missed in your soap?  Grab your phone…unlock it…open the app (which probably closed)…if it’s an IOS device wait 30 seconds while it reconnects to the chromecast…then press backup…wait while it goes through…now keep pressing because by now you are 2 minutes further than you were when you started.  Arrgh!

It’s not all bad news.  It generally works pretty well if you play things from beginning to end, has a lot of services, and I can redirect the screen from my PC browser or Android tablet on to the big TV screen.

Ultimately though we came across a Groupon to buy a Roku device and now have a much more normal viewing experience.  Easier to navigate, no apps needed, and a normal remote control that reacts instantly.  My advice? go straight for the Roku unless you want to drive your family crazy.

What did we miss?

Some shows were simply too difficult to watch and we stopped.  Big Bang Theory was playable but only after jumping through hoops.  Tennis (US Open and Wimbledon) likewise required much hoop jumping.  And Formula 1 was impossible to watch.  F1 was the biggest thing that I personally missed.

homephoneGet rid of the home phone ASAP!

The home phone cost almost as much as the high speed internet…and no-one used it.  About 6 times a day we would get calls telling us our credit card interest rate could be lower or we had won a cruise.  Why was I paying nearly $40 a month for that? 

As soon as everyone had a cell phone we should have ditched the landline but, instead, we held on to this relic far too long.

Finally there?

Overall, the current setup looks like a good deal.  It took a while for the cable companies to catch up but it looks as though we are now almost at the point I wanted to be 2 years ago and my cable bill is 1/4 of what it was.

I’m off now to watch F1 qualifying for the first time in 2 years 🙂

 

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Filed under Life - or something like it, Technology

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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Filed under Education, Technology

Building an F450 Quadcopter – She’ll no take the strain Captain!!

I added a gimbal, larger battery, FPV TX and LED lights to Gerry (my daughter’s name for the quad).  But what happens when you add too many farkles to your quadcopter build?

When flying around on a perfectly calm day it was OK, but still lost altitude on runs and would occasionally stall and twitch.  But anything more than a breeze and Gerry was all over the place and a constant assault of wind would actually cause it lose so much altitude that it would crash.

Why is this so?

This picture from the log tells an interesting story – at least it is interesting to me.

TooHeavy

Red line is Throttle In (what I’m doing). Green line is Throttle Out (what the flight controller sends to the motors).
Blue line is altitude (graphed on the right).  Time (min) can be seen across the top.

The flight controller has a value (THR_MID) that adjusts the throttle so that the middle on the controller provides enough power to hover.  For example if the quad is heavy then it might take 60% of throttle to actually maintain a hover and this allows the user to still position the throttle in the mid point.  These can be graphed showing the Throttle In (from the transmitter) and Throttle Out (how much power the flight controller is sending to the motors).

The problem is that if the THR_MID is way off then switching between modes that automatically adjust (Loiter, Pos. Hold, Alt. Hold) and ones that don’t (Stabilize) can cause a sudden change in the throttle being applied.

At the 1 minute mark on the graph we can see the throttle is between 40-60% in Pos Hold mode and the quad should be holding altitude.  But on this day it was windy and we can see as the altitude goes up and down and the throttle is bouncing off the 100% mark.  Clearly it is struggling to keep the quad at the right altitude.

Just before the 3 minute mark I switched to stabilize, the Throttle Out drops to the same value as Throttle In and the quad starts to fall…FAST!

I immediately give it full throttle but it’s not enough to stop it hitting the deck in what can best be described as a ‘hard landing’.

sadwalkI tried again and the quad was really struggling to maintain altitude – you can see Throttle Out bouncing off 100% repeatedly. Despite the APM putting out near 100% the 5 min mark it continues to lose altitude and my desperate application of full throttle does nothing. It hits the deck again and I decide it’s time to go home.

If you were to place a ruler on the green throttle out line and draw a straight line that best fit the data; you will see that it has an upward slope. The reason for this is that the battery voltage is dropping as the battery runs down.  Since motor speed is a function of voltage fewer volts = less lift.  Basically the quad is under powered for the weight it is carrying.

I tried using a smaller battery to cut weight but it still lost altitude, was still twitchy (where it would periodically stop to correct itself) and near the end of battery life it started going up and down in a very odd fashion.

Baphomet-pentagramFrankly it felt possessed and I started to wonder about exorcism as a real option!  I later figured out this was because it was starting to start the auto land because the battery was low, but then as it dropped the voltage would climb and back up it would go. 

At home more googling and chatting with friends on Quadcopters (yes, I now consider many of these folks friends) and a possible solution emerged.

The PILOT_ACCEL_Z value is used to tell the APM how fast it can climb.  By bringing this down from 250 cm/s to 50 cm/s it should mean that the APM flight controller won’t ask for more than the quad can give and that should stop it getting confused.  I also properly calibrated the battery so that the auto land didn’t kick in too early, as it was consistently under reading the actual voltage by about 1v.

I took Gerry out for a fly and…what a difference!  Smooooooth flying.  None of the crazy jerkiness that it had before and almost no altitude loss.  It did eventually start to lose altitude but it was now controllable and could be recognized for what is was – a battery that was getting low.  Sure enough each time the altitude loss started to occur the low battery beeper would go off.  I ran through three batteries and walked away with a smile on my face.

So, there we have it.  I now have a quad that flies beautifully and is no longer possessed.  With the smaller batteries flight times are short but the future plan is to upgrade the battery to a 4S  (which can output up to 16.8v) which should mean the quad has enough power that I can start to increase the PILOT_ACCEL_Z rating to give it a little more zip.

IMG_1653

*** Pro Tip ***

If you want to know what value THR_MID should be set to, fly in stability mode for a couple of minutes, land and then check the value being displayed in TRIM_THROTTLE.  If it is over 700 you have a seriously underpowered copter.  Under 300 and you are massively overpowered.  

Adjusting your THR_MID value to the same as TRIM_THROTTLE will make transitions between manual and automatic (atl. hold, pos. hold etc.) modes much less troublesome.

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Filed under Building Multirotors, Drones, Technology

Building an F450 quadcopter – Maiden Flight!

We finally had a break in the weather long enough to get outside and get up in the air!

Before leaving there was some question about which two flight modes I should start with.  Key candidates were Stabilize, Altitude hold and Loiter.  I finally opted for the first two.  Stabilize because it doesn’t rely on anything fancy, and then Alt. hold to make flying a little easier.

The result?  In a word – awesome!  It’s been a while since I was able to fly and it was great to finally get back into the air.   See for yourself.

The F450 has some wobble to it.  Nothing terrible and it should be something we can fix using the Autotune feature of the APM.

S. loved it and wanted to try it out, but was too nervous.  That’s actually good as I would really like things 100% sorted before she does that.  But in the car on the way home she told me she wants a little quadcopter that is all her own 🙂

What a wonderful journey!

I’ve shared my parts list including links to where I bought things in case anyone is interested.  You can see those details here.

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Filed under Building Multirotors, Children, Drones, Technology

Building an F450 Quadcopter – Day 6 – Ready to Fly?

AssemblyFinally the weekend arrived and, with the new flight controller in hand, we could get to work.  S. was at a sleepover again so on Friday I performed the ESC calibration and confirmed that in all motors were finally working!

Unfortunately when I tried to run a normal flight test (minus the props) the double flashing red LED told me the pre-arm checks were failing.

I pondered the problem for a while and then realized the FC was in loiter mode which requires a GPS signal to work.  There’s not much GPS signal reaching my basement!  Switching it to “stabilize” mode had it firing up and we were finally ready to put everything together.

IMG_1544I waited for S. to arrive and we set to work.  She installed the anti-vibration plate, flight controller and radio receiver.  I put the GPS post together and she added the GPS to that.  The post had a little hinge on it and I couldn’t understand why, so when S. asked me which way it should go I told her it didn’t matter.  I figured out later that it allows for lowering the mast for transport.  By pure luck it turned out we had installed it correctly.

We had a hard time figuring out where to put the power module and it ended up awkwardly squeezed alongside the battery.  That might need to be moved if we decide to go for a larger battery in the future.

IMG_1556S. checked the motor rotation, installed the props and then, all too soon, it was ready to fly!  It wasn’t pretty but we were both over the moon with it.

S. had insisted that we set up my phone to record a time-lapse video, which I had to admit was fun to watch.  See below.

Not much to do now but give it a test flight, or so I thought.  With the conditions outside being 13f and 20-30mph winds it looked as though we would have to hold off for now.

To be honest I was nervous about this first flight.  I’ve seen a lot of videos where something small or silly caused the quad to flip and when it happens, it happens FAST!  

I went to bed worrying about that and, as is often the way, woke up with an idea on how to make that first flight almost foolproof!

Next post:  The first flight (why second guessing your daughter is a bad idea).

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Building an F450 Quadcopter – Day 5 – Flight Controller Test – FAILED!

After putting the frame together I figured it would be a good idea to bench test the flight controller, ESCs and motors before we actually attached them to the bird.  S wasn’t around so I had to do this sneakily, figuring I would then repeat the process for S once I knew what I was doing.

APM RotationIn theory all I needed to do was hook up the motors to the flight controller, connect to the power module and give it a whirl.  The first question was which way around the FC connector wires go, but a quick question and I confirmed that the white wire goes towards the middle of the FC.  I had the motor order from the APM website and I was ready to go.

I connected the battery, moved the stick to the bottom right which should arm the motors and…nothing!

After some fiddling (and some blind luck) I figured out that I had the throttle reversed on the transmitter.  This video helped me to sort that out.

Unfortunately I now had a bigger problem.  I could arm the motors but only 3 of the 4 would spin.  Motor number 1 (front right and connected to APM output #1) was NFG.

Back to those cool guys on Quadcopters who pointed out that I really needed to calibrate the ESCs.  Oh yes (doh!). Armed with the knowledge that I had missed a step I went back.  But, even after calibration, motor 1 failed to start.

Motor 1 happened to be the one that I had left the power cable connected (for backup) so I wondered if that was the problem.  I removed the wire without cutting it (this time), reassembled and…still nothing on motor 1.

Now we were in full on trouble shooting mode.  I tried starting things and wiggling wires and calibrating the ESCs individually.  Nothing worked.

Screenshot 2015-01-25 22.15.30There is a way that you can connect a computer to the APM and have it run a test on each of the motors.  To do that you need to connect to the “console”, but each time I connected to the console I ended up with spurious characters appearing on the screen and I couldn’t enter any commands.  I tried all of the methods people suggested to get around that and finally came across a post with a person who seemed to have a very similar problem. His problem was solved by replacing the APM flight controller!

I was now starting to think I had a hardware issue.  I tried one last test which was to switch the connections on the APM between motors 1 and 4.  When I started up this time motor 1 (previously not working) fired up fine and motor 4 (previously fine) was no longer working, thus indicating that output #1 on the APM is the culprit.

Since I was still within the 30 day money back guarantee (just) I started a return with the company I bought from on EBAY. I posted this on the FB Quadcopters group and one the most helpful people there – MG – who had been making suggestions and providing encouragement all along said that he would send me a spare APM that he happened to have to avoid the wait time involved in returns and re-shipping,!  No payment, wouldn’t even accept shipping.  Just said to try it out and we can work out what to do once things were up and running.  Amazing!

So, for a short time at least, the fun and games has to stop.  But not for too long – MG’s APM should be here in a couple of days, assuming the snow doesn’t get in the way.

I’m constantly humbled by the outpouring of advice and support the Quadcopters group has provided and only hope that one day I will learn enough to pay it forward.

Stay tuned…we will get this bird in the air yet!

*** Pro Tip ***

The console has now been retired and the motor test functionality moved and can be found under the setup menus in Mission Planner.

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Filed under Building Multirotors, Drones, Education, Technology