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April 2017
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Test, please ignore

Testing out a new code syntax highlighter plugin

MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
[commandCenter.togglePlayPauseCommand addTarget:self action:@selector(playPauseButtonPressed:)];
[commandCenter.skipBackwardCommand addTarget:self action:@selector(skipBackward:)];
commandCenter.skipBackwardCommand.preferredIntervals = @[@(30)];
[commandCenter.skipForwardCommand addTarget:self action:@selector(skipForward:)];
commandCenter.skipForwardCommand.preferredIntervals = @[@(30)];


<p>if($_SERVER['REQUEST_METHOD'] == 'POST' &amp;&amp; isset($_POST['passenger'])){
  // User has filled in the flight info, so create the pass now</p>

<p>// Predefined data
  $labels = array(
    'SFO' => 'San Francisco',
    'LAX' => 'Los Angeles',
    'LHR' => 'London'
  $gates = array('F12','G43','A2','C5','K9');

import feedparser
import PyRSS2Gen
import datetime
import re
import cgi
import cgitb; cgitb.enable()</p>

<p>entry_no = 1</p>

<h1>get val</h1>

  f = open('/tmp/rss_feed_count.txt', 'r')
    num = f.readline()
    entry_no = int(num)

How to Become a Maker

Soldering station. Image credit: Windell Oskay

Image credit: Windell Oskay

Once again I have had the pleasure of appearing on Allison Sheridan’s podcast, the NosillaCast. On Sunday, March 1st’s show (#512! a nice power-of-2 binary number!) we talked about getting into the whole “maker” movement, and how to build cool things using micro controllers such as the Arduino, as well as single-board computers such as the Raspberry Pi. Listen to it here (starts in around 33:25) and read the show notes below.

Continue reading How to Become a Maker

How to Build your own Quadcopter

My first quadcopter buildOn Episode #509 (Sunday, February 8) of the NosillaCast, I talked with host Allison Sheridan and her husband Steve Sheridan about my latest obsession, building your own quadcopter.  When the Parrot AR Drone came out at CES several years ago, it really captured the attention of first the tech press and later the general public, and I think is really the start of the current popularity of quadcopters.  Unfortunately the AR Drone and its friends are still beyond my reach price-wise.  However, just like in the early days of PC computing, it is possible to buy a pile of parts and put together your own quadcopter, often for far less than what you’d pay for a comparable commercial craft.  Furthermore, building your own quadcopter allows you to build a craft to your exact specifications — features, flight characteristics, handling, fly time, etc.  It’s also both educational, and fun!  Here are the show notes from that segment, which starts at 0:25:38.

The problem to be solved:

  • Ever since the Parrot AR drone came out (the first quadcopter to really capture the public’s mindshare) I have wanted one.  But even before that I have always been curious about model aircraft.
  • The problem is that they are still pretty expensive (e.g. Parrot AR drone is still around $300)
  • But, as it turns out, you can build your own quadcopter out of parts!

Building a quadcopter vs. buying one?

  • Let’s take a step back…
  • Back in the early days of the PC, you could buy one from a company, but they were expensive.  Or you could build your own by combining parts (motherboard, hard drive, RAM, video card, sound card,  etc.)  Often you could save quite a bit of money this way, plus you could pick the exact kind of parts you wanted (e.g. higher end/specialty video and sound cards for gaming, CAD, etc.)
  • These days PC hardware is pretty much commoditized, so while you can still build your own, it doesn’t really save you that much money, plus there are retail-bought computers that cover most of the specialty cases (e.g. Alienware PCs for gaming, etc.)
  • Well the same is true for quadcopters (as well as model aircraft in general).
  • You can buy off-the-shelf quadcopters.  They’re pretty good, but are still fairly pricy.
  • But, unlike PCs, it is still economical to build your own quadcopter out of parts.  And, more importantly, you can build a quadcopter to fit your own specifications (features, flight characteristics/handling, etc.) by choosing different parts.  (Race car drivers don’t just go and buy a race car, they have them purpose-built; even NASCAR cars, which are ostensibly based on stock automobiles, are still heavily modified/customized.) 

Basic theory of operation of flying vehicles

  • Airplanes:
    • Lift is generated by the flow of air over an airflow (i.e. wing.)  The wing’s shape causes air to flow faster over the top surface, which decreases the air pressure.  The higher air pressure on the bottom of the wing generates lift.
    • Direction of travel is controlled using various control surfaces.
      • Up/down direction is controlled by the elevators, movable panels on the horizontal surface of the tail.  They direct airflow upwards and/or downwards, which raises/lowers the nose of the plane.
      • Left/right direction is controlled by the ailerons, movable panels on the wing.  Raising/lowering them will raise/lower the corresponding wing, causing the plane to bank, which causes it to turn.  The rudder, a movable surface on the vertical part of the tail, is also used to point the airplane’s nose in the appropriate direction.
    • The engines (propellers, jets, etc.) just serve to push the plane forwards, which causes the airflow over the wings, etc.
    • It should be noted that an airplane is aerodynamically stable, meaning once it’s flying, it tends to continue to fly, even if you take away all the power, etc.
  • Helicopters:
    • The big propeller (rotor) at the top of the helicopter is its main control surface.  It functions rather like a giant wing.
    • Spin it faster and you go up, spin it slower and you go down.
    • You go in a direction by varying the pitch of the blades.
    • But without another force to oppose it, the rotating of the rotor would cause the helicopter’s body to rotate in the opposite direction.  That’s what the tail rotor is for.  It counteracts the effects of the main rotor’s rotation on the helicopter body.  It is also used during turning to point the helicopter’s nose in the direction you’re going, similar to how the rudder in an airplane is used.
    • It should be noted that, unlike an airplane, a helicopter is not aerodynamically stable in and of itself.  (i.e. without power, it’ll fall out of the sky.) 
  • Quadcopters (and other multi rotors): 
    • Lift is provided by multiple rotating propellers. 
    • Quad (= 4 blades) is the most common and easiest/least complex.
    • Generally, the more sets of blades you have, the more stable a craft is, and it also allows for redundancy; if you lose a motor/propeller you won’t fall out of the sky. 
    • You have to have an even number of propellers (4, 6, 8, etc.), with half of them spinning clockwise and the other spinning counterclockwise (to counteract the opposing forces.)
    • There are bicopters (2 blades) and tricopters (3 blades) but they are more complex and are weird, and are not the best choice for a beginner. 
    • Normally quadcopter blades are not variable pitch, so how do they move around?
      • Spin all the blades faster or slower to go up or down.
      • Spin one set of motors faster or slower than the others, that causes the quadcopter to tilt in a given direction and start moving in that direction.
      • Turning (pivoting, yaw) is accomplished by spinning the blades on opposing corners at different speeds.
    • Like helicopters, quadcopters are not aerodynamically stable

Direct Flight vs Fly by Wire

  • In the old days airplanes were direct flight.  You push on the control column, and you are directly manipulating the control surfaces (either they’re connected directly to the controls via cables, or they’re connected remotely by use of hydraulics.)  Some older commercial airplanes and most private planes are like this.
  •  Most modern commercial aircraft are “fly by wire” meaning that they are computer controlled.  When you push on the control column, you aren’t directly manipulating the control surfaces.  Instead, you’re telling the Flight Computer what you want to do, and it decides which control surfaces it should move, and by how much, to achieve the desired result.
  •  This takes much work off of the pilots and results in safer, more efficient flight.
  •  Because a quadcopter is an aerodynamically unstable craft, it must have a flight controller managing it and therefore quadcopters are, by nature, fly-by-wire craft.  (The minute, nanosecond-level adjustments to the speed of each propeller required to even stay in the air, let alone move around, is way more than any human is capable of doing. 

Your First Quad

  • Before you think about building your own quadcopter, you might want to learn how to fly a quadcopter first… 
  • Either borrow a friend’s (and ask him/her to teach you) or get yourself a “trainer” – one of those cheap quads that are starting to come out now.  Here are some good recommendations:
  • They are relatively inexpensive (around $40-60) so if you lose/damage/crash them you’re not out a ton of money (Plus they are actually pretty indestructible.)
  • Good enough to give you some basic flight training, learn how to work the controls, get used to the physics of flying quadcopters, etc.

What are the parts that go into a quadcopter?

  • Frame 
  • Flight Controller
  • Radio receiver
  • Motors
  • Electronic Speed Controllers (ESCs)
  • Propellers
  • Power distribution board (or wire harness)
  • LiPo battery

Other stuff you’ll need

Quadcopter FrameThe Frame

  • Holds all the stuff together (obviously)
  • Some are unibody, others require assembly. 
  • They are numbered (e.g. “a 230″, “a 250″, etc.)  This is size (distance between props) in mm. (Sometimes (inaccurately) called “wheelbase”)
  • Some contain mount points for additional stuff (cameras, steady cam type rigs, etc.)
  • General rule of thumb: (there are always exceptions of course)
    • bigger = more room to mount stuff, more stable/less vibration, more difficult to control, less agile/maneuverable, more carrying capacity, but usable only outdoors (unless you have like a warehouse or aircraft hanger or something), more expensive, requires larger/heavier propellers/electronics/batteries, harder to transport, could really hurt you
    • smaller = less room to mount stuff, faster, more agile/maneuverable, easier to control, more prone to vibration, can fly indoors or out, cheaper, can use smaller/lighter propellers/electronics/batteries, easier to transport, not likely to injure you
  •  Can be made of a wide variety of different materials (wood, metal, plastic, glass fiber, carbon fiber, etc.)  You don’t even need to buy a pre-made frame, you can fairly easily make one yourself!
    • Most common is glass fiber – reasonably light, inexpensive, and pretty durable 
    • Carbon fiber is the lightest but is also the most expensive, and is brittle (i.e. usually breaks when you crash it.) 
  • First time build recommendation: It’s probably a good idea to start on the smallish side (230 or 250) for a first-time build
    • The HobbyKing Spec FPV250 is a great 250-class kit, which contains most of the parts you’ll need (frame, motors, ESCs, battery, etc.)  It is easy to assemble and requires no soldering, and is darn near indestructible. It even has a camera mount, if you want to add video capability later.

Flight ControllerFlight Controllers

  • The “brain” that handles all the flying
  • Receives input from the radio receiver, translates your inputs to the appropriate motor commands, and sends control signals (how fast/slow to spin the motors) to the ESCs
  • Be sure and install them in the correct direction!  They usually have some sort of indication (arrow, lettering, etc.) indicating which side should face the front of your craft. 
  • They use sensors to determine the craft’s orientation, they use this information to keep the craft steady and to decide how to command the motors based on the commands you give it.
    • Bare minimum, Gyro/Accelerometer (just like in your iPhones) – tells the thing if the craft is level or not (or how far it’s tilted), and how fast it’s moving in various directions
    • More advanced FC’s have additional sensors
      • Barometer – allows for altitude hold (automatic hovering)
      • Magnetometer (compass) – allows for heading hold
      • GPS – allows for automated flight, and “return to home”
      • Some are even experimenting with other types of sensors (ultrasound or IR sensors for obstacle avoidance, etc.)
  • Some FCs can output telemetry over a wireless/Bluetooth link (lets you look at flight characteristics “live” while in flight)
  • There are some commercial flight controllers, but most are Open Source, which also means that you can tweak them to your heart’s content! 
  • First time build recommendation: the KK2.1.5
    • Does not require a computer for configuration (all configuration can be done via its built-in LCD screen)
    • Very gentle, easy to fly, but can be tuned for more high performance flying 
  • For the more advanced: The Flip MWC 1.5
    • Requires a computer to configure/tune it.
    • By default will give you very stable, gentle flight, but can be heavily tuned (it was designed with acrobatics and trick flying in mind) 
    • Can be configured with a magnetometer and barometer
    • Fully Open Source – the ultimate in tweakability 
    • Has a really cool GUI utility that lets you configure it and also shows the flight characteristics just like an airplane cockpit


  • They spin the propellers, obviously
  • Usually you’ll see a “KV” number associated with them – that is the # rotations per volt (ideal conditions, i.e. zero load)
  • Lower KV (1000, etc.) are less efficient but give more torque and can use larger propellers, whereas higher kV motors are more efficient and can turn faster but give less torque and work well with smaller propellers
  • Think of it like gears on a bicycle, if you cycle at a lower gear, you go fast, but pedaling is hard, and eventually you hit a point where you need to shift gears
  • Bottom line: smaller/higher KV = good for smaller quads, larger/lower KV = good for larger quads
  • Make sure max. current draw matches the max. output of your ESCs.
  • On really good sellers’ sites, you’ll see some other numbers, most notably Thrust (in grams).  Use this to calculate your lift capacity.  (If you don’t have thrust, you can calculate it yourself by running your motor while placing it on a scale – crude but it gives a reasonably good approximation.)
  • You want at least a 1.5:1 (and ideally 2:1, or even 3:1) thrust:weight ratio.
  • Remember, there are lies, darn lies and benchmarks.  So allow a healthy margin of error in your calculations!  


  • A wide variety of sizes and materials
  • Primarily listed by size (X x Y)
    • The first number is the length (diameter) of the propeller
    • The second number is the blade pitch – for every revolution, it pulls you X inches forward (under ideal conditions, with no load, blah blah blah)
  • Choosing the right prop is a balancing act
    • Larger diameter = increased lift capacity
    • Larger pitch = increased top speed and maneuverability
    • Smaller and/or lower blade pitch propellers can be sped up/slowed down easier (less inertia) – very agile, good for acrobatics/trick flying
    • Increasing either (or both) = increased load on your motors = increased battery draw = less flight time (unless you put in a bigger battery, which then means more weight to carry around, etc.) 
  • Most common is nylon/plastic – these are pretty cheap and are probably the best place to start
  • Another popular choice is carbon fiber – they’re stiffer, so cause less vibration, and are also quieter, and are also lighter and stronger, but are brittle (can shatter on impact)
  • Remember they have to be purchased in pairs (e.g. for a quadcopter, 2 clockwise and 2 counter-clockwise)
  • Some are made for airplanes, and they’re “okay” but one that has been made/certified for multirotor use is always the best choice


  • Translates commands from the flight controller (“spin at X RPM”) into the appropriate voltage level to send to the motors
  • There are three sets of connections that you need to make – one goes to the battery (red and black wires, positive and negative), a smaller set of wires that goes to the flight controller, and a set of three wires that go to the motors
  • To change the direction that the motor spins, just reverse any two of the motor wires 
  • ESCs are widely used in the model airplane/helicopter world, but the ones that we use in quadcopters need to be configured in a special way to work the best in a quad (airplane ESCs do throttle smoothing – we don’t want this on a quad, where throttle/motor speed changes quite frequently)
  • Fortunately most ESCs can be firmware upgraded to tweak them to work with quadcopters (remove the smoothing function, etc.) – most popular firmware for this is the “SimonK firmware” – you can buy an ESC yourself and flash it, but you might as well buy them pre-flashed (flashing SimonK firmware onto an ESC can be kinda tricky and usually requires soldering and special cables)
  • ESCs are rated in Amps – you need to match the ESC with the power draw of the motor it’s hooked to 


  • Quadcopters (and indeed most model aircraft these days) are powered by LiPo batteries, very similar to the batteries that power our phones, tablets, computers, etc.
  • But unlike the batteries that are in our gadgets, these batteries are “naked” (i.e. no case enclosing them) so they are susceptible to damage (i.e. puncturing) – mount them accordingly (i.e. in the most protected spot on your quad that you can muster)
  • Also need to be careful when charging them (again, our devices have circuits preventing overcharging, etc., these packs usually don’t, and put the onus on making sure that they aren’t overcharged, etc. onto the charger, so get a good charger!)
  • Several numbers associated with batteries:
    • Volts – how much electricity is in the battery.  Higher Volts = more energy for the motors to turn (i.e. faster motors)
    • Amps – the amount of current the battery can put out.  Confusingly they are sometimes listed as milliamps (i.e. 2200 vs. 2.2) – in that case just divide by 1000.  This represents the total amount of energy that the battery has to give.  The higher the Amps, the longer your flight time.
    • S/P – individual LiPo cells are 3.7 volts.  To make a pack with a higher voltage, you wire multiple cells in series (that’s the S number).  Or, if you want to keep the voltage constant, but make a pack with greater amperage, you wire them in parallel (that’s the P number.)  You almost never see greater than 1P (which is why the P part is often omitted entirely) but almost always see multiple S (e.g. 2S = 7.4 volt pack, 3S = 11.1 volt, etc.)
    • Max Discharge Rate –  expressed as “x C” = the rate at which the battery can safely deliver power.  This is in multiples of the pack’s amperage.  For example, a 2.2 Amp 25C pack can deliver power at a rate of up to 2.2 * 25 = 55 Amps.  Usually two numbers are listed, the lower one is the sustained rate, while the higher one is the burst rate.
    • Max Charge Rate – also expressed as “x C” = the maximum rate at which the battery can be safely charged.  This is also in multiples of the pack’s amperage.  For example, a 2.2 Amp battery with a 3C rating can be charged safely at a rate up to 2.2 * 3 = 6.6 Amps.  The higher the number, the quicker the charge time.  But you almost never want to charge at that high a rate, because it lessens the battery life.  Usually most people charge at 1 C (i.e. for a 2.2 Amp battery, charge it at 2.2 Amps), that is a good balance between battery life and charge time. 
  • You want to get a battery that can deliver enough power to all of your ESCs – so take their Amp ratings and multiply by 4, and add a little on top – e.g. for 12 Amp ESCs, you’d want 12 * 4 = 48 Amps + a little bit
  • Watts = volts * amps
    • E.g. for a 11.1V 1A 25-35C pack, 1A * 25C = 25A sustained discharge rate, 1A * 35C = 35A burst discharge rate
    • Sustained watts = 11.1V * 25A = 277.5W, burst watts = 11.1V * 35A = 388.5W
    • Divide this by 4 to determine the # of watts it can supply per motor, make sure it matches up with your other gear (give yourself a little margin of error too) 
  • IMAX_B6ACTo charge these beasties, you’ll need a balance charger
  • Here’s how you charge them:
    • plug in charger, select LiPo mode, select Balance mode
    • input battery capacity (S number, i.e. voltage) and charge rate (C number, i.e. amps)
    • plug the battery’s discharge leads (the thick ones) into the charger, then plug its balance leads (the thinner one) into the balance plug
      • VERY IMPORTANT! Plug the charge leads into the charger FIRST, THEN plug them into the battery! – this minimizes the chance of accidentally shorting out the leads (which would be BAD!) 
    • the charger will detect the battery type, confirm that it matches what you input, then hit Start
    • the charger will show you stats as it’s charging, and will beep when it’s done 
  • This is one area where you really do not want to cheap out.
    • BE CAREFUL – there are a lot of clones/counterfeits! 
  • First time build recommendation: IMAX B6-AC  

FlySky FS-T6 Transmitter and ReceiverReceiver/Transmitter

  • Each manufacturer has their own standard (i.e. you can’t use a Futaba transmitter with a FlySky receiver)
  • Buy them as a set
  • You only need one transmitter, if you build more quads, you can buy extra receivers separately
  • Must be “bound” (sort of like Bluetooth pairing)
    • The receiver that came with your transmitter set is usually pre-bound, but if you buy an additional receiver, you’ll need to bind it
    • Usually they come with a “bind plug” – you insert it into the “BAT” socket, power up the quad (which powers up the receiver) then power up the transmitter while holding down the “bind” button
  • Some of the more advanced systems can do some cool things, for example “satellite” receivers – multiple receivers with antennae pointed in different directions = better coverage at longer ranges, plus redundancy
  • First-time build recommendation: FlySky FS-T6 

So how does it all go together?

  1. Get a small plastic container and put a few drops of thread lock in it.  To use the thread lock, dab the end of a screw in it, and swirl it around a bit to coat.  You only need a small amount on it, so if you end up with a huge blob of thread lock, shake some of it off.
  2. Thread the velcro strap through the slots in the middle of the frame – this will hold in your battery and the wiring.
  3. Mount your flight controller in the center of the frame.  Be sure its front is lined up with whatever you want the front of the quad to be (usually the little bracket for the camera mount.)  Secure it with four screws.
  4. Mount the motors at the end of each of the arms.  Thread the motor wires through the holes in the arms to get them out of the way.
  5.  Place the ESCs at the mid-point of each of the arms.  Connect the three motor wires to the three wires of the ESC.  Secure them with zip ties.
  6. Plug the small wires from the ESCs into the flight controller.  For the KK2.1, use the set of pins on the right of the board.  Plug the left front motor into the top row of pins, the right front motor into the second row of pins, the right rear motor into the third row of pins, and the left rear motor into the 4th row of pins.  The yellow (or white) wire should be facing inwards (towards the LCD), the black wire should be facing outwards, and the red wire should be in the middle.  If you are using a different flight controller, consult its documentation.
  7. Plug the radio receiver into the flight controller.  For the KK2.1, use the set of pins on the left of the board.  Plug one set of radio wires into Channel 1 of your receiver.  For the FlySky receiver, the yellow (or white) wire should be facing left (towards the label), the black (or brown) wire should be facing away from the label, and the red wire should be in the middle.  On the KK2.1, plug the other end of this wire into the topmost row of pins on the left side, with the yellow (or white) wire facing toward the LCD and the black (or brown) wire facing towards the outside.  Now, plug the other wires vertically across Ch2-5 of the receiver, and vertically across the right most pins on the left side of the flight controller.  (This is kinda hard to describe, check out this diagram or watch this episode of Know How for a better idea of what I’m talking about.)
  8. Plug the ESCs into the power distribution harness (red to red, black to black.)  Make sure the other end of the harness is near where the battery will mount (on the bottom of the craft.)
  9. Plug the buzzer into the KK’s Buzzer port.  Red pin goes on the right.
  10. Turn on your transmitter! 
  11. Finally, plug in the battery.  You should hear some beeps, and the LCD should light up and show some information.
  12. Hit the right most button (MENU), scroll to “Load Motor Layout,” and hit Enter.  You will be presented with a list of different multi rotor configurations.  Select “QuadroCopter X mode.”  Hit the right most button (Enter).  You will be asked if you are sure.  Hit Yes.  It will then show you a picture showing which way each motor should turn (we will fix the motor rotation in a bit, so you can ignore this.)  Hit the left-most button (Back) until you have exited the menus and are back at the “SAFE” screen.
  13. Hit the right most button (MENU), scroll to “Receiver Test,” and hit Enter.  Move the sticks on your transmitter.  The corresponding values should increase/decrease in the proper direction.  If they are reversed, use your receiver’s “Reverse” function to swap them.  Once you’ve made sure all the controls are moving in the right direction, use your receiver’s trim or sub trim to make sure all values read out as 0.
  14. With the propellers OFF, move the left stick all the way down and to the right.  The board should beep and show “ARMED.”  Now quickly move the left stick (throttle) up, then down.  The motors should spin up.  Watch them to see what direction they’re spinning in.  (It helps to put a piece of tape on the shafts.)  The front left and rear right motors should be spinning clockwise, and the front right and rear left motors should be spinning counterclockwise.  If any of the motors are spinning wrong, swap ANY TWO of their wires. 
  15. Make sure the battery is disconnected from the quad.  Turn on your transmitter, and move the left stick (throttle) all the way up.  While holding down the leftmost and rightmost buttons on the KK2.1, plug in the battery.  You should hear a beep.  While still holding down the leftmost and rightmost buttons, move the left stick (throttle) all the way to its lowest position.  You should hear some more beeps.  Now let go of the buttons.  You have just calibrated your ESCs so that they know what the minimum and maximum possible values for throttle are.
  16. Double-check all your wiring, and when you’re satisfied, lock down your ESCs, radio receiver and wiring to the frame using zip ties.  Make sure that your wires aren’t locked down super tight (i.e. leave a little bit of “give.”)
  17. Finally, attach your propellers.  Clockwise propellers go on the front left and rear right motors, while counterclockwise propellers go on the front right and rear left propellers.  An easy way to tell which is which is to hold the propeller in your hand, with a blade facing up.  If the “hump” on the blade is on the right side, it’s a clockwise propeller; if the “hump” is on the left side, that is a counterclockwise propeller.
  18. You’re now ready to fly!  
  19. By default, the quadcopter boots up in “SAFE” mode.  This means that control inputs are ignored, so that, e.g. if you accidentally bump the throttle, the motors won’t suddenly spin up on you.  To arm your quadcopter (prepare it for flight), move the left stick all the way down and to the right.  You should hear a long beep, and the screen will show “ARMED.”  Now, moving any of the controls will actually cause the quad to move.  To disarm, move the left stick all the way down and to the left.  The board should beep and the screen will show “SAFE.”  You should move/pick up your quadcopter ONLY while it’s in SAFE mode! 

“Don’t Be a Jerk”

  • Don’t fly near airports
  • Don’t fly near crowds, especially if you’re a new pilot and/or haven’t thoroughly tested your craft to make sure it doesn’t do anything weird
  • Don’t fly near any government/military buildings
  • Don’t fly while drunk/high
  • Start out flying “line of sight” – i.e. don’t lose sight of it!  Either keep an eye on it yourself (takes some training) or bring a friend to act as your “spotter” 
  • Stay below 400 feet AGL (above ground level)
  • Right now drone flyers are in a very precarious position, as the FAA is still trying to make up its mind on the subject, so we really need to be on our best behavior
  • Also support The Academy of Model Aeronautics – the main model aircraft club in the USA.  Historically they have worked closely with the FAA to legitimize the hobby, and they are our best bet for keeping quadcopter flying legal. 

Some other last words

  • Steve quadcopter stuck in tree

    Oops… ;-)

    Go easy on your first few flights.  Find a nice large area to practice in, as level as possible and as free from obstructions as possible.  Go easy on the controls, don’t hammer them.  Practice hovering (riding the throttle to keep as level as possible) and horizontal movements before attempting turns.  And remember, quadcopters generate their own turbulence when close to the ground (around 4 feet or lower), so once you go past that, it’ll fly a lot easier; also landings are easier if you’re moving horizontally while you’re landing.
  • Learn to solder – it’s really not that hard, and you’ll need it once you go to more advanced builds
    • Dave Jones at the EEVblog did an excellent 3-part tutorial on soldering: part 1part 2part 3
  • Use bullet connectors – makes swapping components around really easy
  • Use the community when you’re choosing parts for a build
  • Some good places to buy stuff

Some other quadcopter builds


Two ways to work around IFTTT’s removal of Twitter triggers

If This Then That kills Twitter If This Then That (IFTTT) is a really powerful service that could best be described as “the ultimate Web 2.0 mashup creation tool.” It lets you bridge Web 2.0 services together in really unique and powerful ways. You create “recipes” that follow the simple syntax “If this then that” (hence the name). The this (which IFTTT calls a “trigger”) consists of an action that you (or someone else) takes on one service (you post a new picture using Instagram; someone tags you in a photo on Facebook; someone sends you an email). When the trigger fires, that is when the that part of an IFTTT recipe comes in to play (which IFTTT calls “actions”). An “action” is something that IFTTT can do on your behalf using a variety of different services (create a note in Evernote; post a link to Twitter; SMS me). Their “about” page does a much better job than I of explaining what IFTTT’s all about, and you can check out the directory of public recipes to see the powerful and creative ways others are taking advantage of IFTTT.

Unfortunately, some recent API and policy changes Twitter has started putting into play has in effect neutered IFTTT’s capabilities as far as Twitter is concerned. While IFTTT still supports Twitter “actions” (so, e.g. you can post Tweets using IFTTT), they have removed all Twitter “triggers.”

Fortunately, with all the Web 2.0 services out there on the Internets, and using some of these services, I have found a way to accomplish the two things I was using IFTTT for, insofar as Twitter is concerned.

Continue reading Two ways to work around IFTTT’s removal of Twitter triggers

SCALE 9x Promo Video, Take 2

The folks at SCALE tasked me with creating a radio promo for the upcoming SCALE 9x conference. I decided to kick things up a notch: not only did I create the requested radio promo, but I also used it to create another SCALE promo video. I present it below the cut for your enjoyment. Continue reading SCALE 9x Promo Video, Take 2

SCALE 9x Promo Video

The Southern California Linux Expo, or SCALE, is a small but growing (when compared to some of the more mainstream ones) Linux conference held every year around February in Los Angeles. I’ve written about it before. It’s a great way to learn about the latest goings-on in the Linux and Open Source community, and is well attended by “suits” and “techs” alike.

This year, SCALE is moving from its former facility, the LAX Airport Marriott, into a new, bigger one, the LAX Airport Hilton, due to the phenomenal growth that SCALE has experienced over the past few years. The new digs are allowing them to add another conference track dedicated to Linux system administration, and is also allowing them to expand expo floor space by a much-needed 20%.

The fine folks at SCALE asked me to put together a promo video for the show. I present it below for your enjoyment.

SCALE 9X is coming! from Southern California Linux Expo on Vimeo.

Testing out a new method of updating Twitter and Facebook

This is just a quick heads-up. I’m testing a new method of updating Twitter AND Facebook whenever I post a new blog or podcast. I’m hoping that this will work without any major snags, but there is always the possibility that it may flood either Twitter or Facebook or both. If this does end up flooding the feed, please accept my sincere apologies. I’ll be monitoring things closely so if things do go wonky I’ll be able to pull the plug quickly. Thanks for your patience and understanding.

SCALE 8x: The Video

Well, SCALE 8x was only two weeks ago, and yet it feels like it’s but a distant memory now. What an amazing conference! The LAX Airport Westin was literally stuffed to the rafters with Linux and Open Source businesses, developers, users, and all-around geeks. The diversity and enthusiasm of the Linux and Open Source community continues to amaze me year after year. And – amazingly enough – there were more than a few companies openly hiring again. Definitely a sign of encouragement about our country’s economic recovery.

This year I once again was working the audio and keynote streaming departments along with my friend Tom King and a really outstanding cast of really dedicated volunteers. We had only one or two audio mishaps this year – most of the talks made it onto the recorders in reasonably good quality. All the audio has been processed and is in the hands of the SCALE staff; it should be on the website and available for download soon, and the keynotes are available to stream off our Ustream channel page.

The SCALE staff decided to try something new this year. On Saturday afternoon, Jason Riker, a member of the SCALE PR team and I headed out onto the show floor armed with a microphone (with perilously short cord – next year we’ll have a wireless rig) and a video camera, and we did some interviews with various SCALE attendees. I edited that together along with some background footage (“B-roll” as they say in “the biz”) I took the next day into this SCALE highlights video that, I think, puts the viewer “in the moment” and allows him/her to experience at least some of what attending SCALE is like. Hopefully those of you who watch this and either have never heard of SCALE, or haven’t made it to one yet, will decide to go next year.

SCALE 8x: The Video from Southern California Linux Expo on Vimeo.

SCALE 8x Keynote Stream of Doom

Can’t believe it’s that time again.. time for SCALE 8x! I’ve been on site since Thursday afternoon, working audio stuff; however tonight I’m taking a break from that and working on video, specifically the Keynote stream. Yup, once again we’ll be streaming the Keynotes. Keep your eye on this post to watch the stream. The keynotes are on Saturday 2/20 and Sunday 2/21, from 10 AM – 11 AM Pacific time. However right now I’m test-streaming the UpSCALE talks, which are pretty fun, so you might want to tune in to those.

Saturday’s keynote is “Being a Catalyst in Communities” by Karsten Wade, and Sunday’s is “So, You Think You Want to Start an Open Source Business” by Tarus Balog.

Anyway, stream can be found below. (If the stream isn’t live, you’ll get the opportunity to watch our previously recorded videos.)

SCALE Keynotes are up on Google Video

Something weird is going on with the SCALE videos I posted earlier on Ustream, so I’ve gone ahead and uploaded them to Google Video. (I also trimmed them somewhat, cutting out the “this is us setting up” bits at the beginning of the video, so they should start right into the actual keynote speech.) Here they are, for your viewing pleasure.

Saturday Keynote: “When Software Is a Service, Is Only the Network Luddite Free?” presented by Bradley M. Kuhn

Sunday Keynote: “Reaching the masses: 10 ways to improve the reach of your FOSS Project” by Joe “Zonker” Brockmeier