Monday, December 15, 2014

There Are Four Quads.


Deadbug: A method for wiring of electronic circuits that involves attaching the components to a substrate, upside down, and then connecting the contact points, point to point.  

Saturday, I went over to SwitchElectricians place, and we spent the day messing with quadcopters.  It was a productive day, we had three different quads get completed.  

Acro quads are a strange.. They're usually an attempt at the minimum airframe to fly, but often err on the "less than minimum" amount of airframe.  That means you need to get really creative with mounting things to it, beyond the usual "hey this isn't the right size" issues that are par for the course. 

In deadbug style, here's the wiring that I did on the HobbyKing Maltese frame.  Now I'm a little disappointed I have the Velcro on there, it doesn't show my cross wiring job.


This quadcopter is flying on a set of 1704, 1900kv motors.  Spinning 5x3 props.  The battery is a 800mah 2s pack.  The flight controller is a KK clone from HobbyKing.  I'll talk about the board later, but for now, lets say I don't like it very much.  It's flying weight is very, very light.  350 grams IIRC.  

Mounting the motors was somewhat difficult.  The motors have a two available mount patterns.  The ones drilled into the motor, and then a X shape bracket you can put on it to mount to larger motor mounts.  The bracket is so large that it is bigger than the arms on the quad.   The built in bolt spacing is between two of the three bolt patterns on the arms of this quad.  To make it work, I had to drill out the smallest spacing with a slightly larger drill bit.  the washers make up for the larger motor mount holes. 

M2 screws and washers are a pain to work with.... 


The board has a fixed "forward."  So the front of this thing, unless I get some kind of adapter board, will make this a "plus" configuration quad.  When I was test flying it, this shape really messed with my head.  You'll notice the red tape and red prop, I did that before I flew it because I knew my brain wasn't going to handle the plus set up very well.    That said, it did fly, and was stable as could be expected from a board without accelerometers. 


Oh look, more deadbug.   The receiver has moved, and there's a few extra wires hanging off the chassis.  Also, the motor leads have lost 5" of excess wire.  In this picture, the quadcopter has a 3s 1500mah battery in it.  It will fit a 3s 2200 as well.  I haven't tried to see if it will balance with a 1000mah 3s in it yet. 

Speaking of balance, the female balance plug on the right side of the picture, is how we decided we were going to provide power for the FPV gear.  It means we can turn on and off the video gear, without the problems that come from switches.  And it gets the video ground as far away from the motor grounds as we can manage.  It should be "better" but I haven't thrown a oscilloscope on the quadcopter to quantify those numbers.  At minimum, it makes me feel better.
 

The Naze32 flight controller moved twice since the last photo.  Because the receiver came off the top deck, the cable for the Naze32 ended up being to short. 
 

Standoffs are a wonderful thing.  To clear the speed control wires, I had to raise the naze32 over the motor deck. Eventually I'll be using the same stack of standoffs to carry my HD flight camera, but that's for another time.  

I'm still trying to decide how I am going to dress the power and signal wires for my FPV gear.  You can see the trimmed plug for the balance connector that provides power to the FPV rig. 
 

The starboard elevation. I'm a little worried about the receiver location, but it's in a case, and should be able to take any hits. 
 

 The video transmitter doesn't stick past the chassis, so should be safe.  The front end of the X-Factor is a very, very busy place. 
 

Doing hobby work at your computer desk isn't recommended.. but it's what I do.   I like how it turned out.  In the next week or so, the flight HD camera mount will be fabbed up, and I'll get my hands on some circular polarized antennas.  (or make them...)
 

SwitchElectrician also had a project to work on.  He picked up the ultra light 250 racer frame from HK.   We built that up too.  It's flying on some 2204's, 20amp Afro speed controls, a 1.5ah 3s battery, and 5x4.5 props. 
 

Let me tell you, it wants to move some air.  We need to get it on a scale, but I think it may have a 4:1 power to weight ratio. You can peek in at the winding on the motors, and they're positively beautiful.  I suspect they were hand wound with how the wire is stacked on each pole. 
 

Saturday was a productive day.  

Friday, December 12, 2014

The Third Quadcopter post.

I ended up with two complete sets of motors when I ordered the parts for the HobbyKing X-factor quadcopter frame.  Since I already had spent $35 on motors, I figured I might as well build a second quadcopter.  So I ordered the $11 HK Maltese frame, their KK 1.5 controller board, and some $6 speed controllers.  

Much to my disappointment, the motor BCD didn't match the holes in the frame.  I had to drill out the holes a little to get enough clearance to fudge the BCD between the 1704's and the airframe. 

As it sits in the following picture, it's 230 grams.  With battery, it's 349 grams.  And it will lose some weight when I trim all the wires. 

Well that's an interesting number.  632 grams.  That's the weight of the X-factor, with a 200mw transmitter, a metal case sony board camera, a HD camera, and a 1500mah 3s battery on board.

It looks like a mess.  I need to shorten the motor wires and do some more cable management.  

I did do some testing the other night, and my $40 goggles work well with my $40 radio set and $15 camera.  Next step, is to fly it.

Sunday, November 30, 2014

Quadcopter, it talks to computers, and it hovers!

Saturday morning, a package arrived. It had bigger motors in it. And, those motors came with all the right screws to mount them. So I got those installed.


Motors need something to make them spin. Those "should" be placed somewhere they'll get airflow.

The frame I'm going to be flying has the sprung lower chassis and the upper "x" frame. I think that to get the most benefit of the shock mounted upper "x" frame, I'm going to try to mount everything I can on the lower pod.

Also, to have the lightest install I can manage, I want to have the motor leads as short as I can manage.. that means mounting the speed controls close to the motors. The closest I can get the speed controls to the motor is on the wings of the pod.  I think they look good there too.


Quadcopters are not stable.  They need a controller to make them manageable.  And even then they can be a bit of an adventure.  As I'll explain later.

Our choice of controller is the Naze32.  They come soldered, and unsoldered, and this time.. we got the unsoldered version.  So out came the soldering gear.  Well.. actually SwitchElectricians soldering gear.


And here's the Naze32 mounted, properly, to my quad-copters top plate.  We chose to mount our controllers up there because the battery is less likely to bash into it, and an impact with the ground isn't likely to cause anything to come up and interfere with it.  Or at least that's the thought.

Mounting the boards where we did, also lead to some problems.  My board is inverted.  And the board assumes it will be right side up and looking forward.  However, that can be handled later.


While I had the soldering iron out, I built the power harness.  I want all of the motors to run the same, and I have a moderate dislike for the PDB (Power Distribution Board) systems out there.

PDB's have a limit on how much copper is available to pass power.  Given that these motors will only draw a maximum of 10 amps each, I doubt a PDB would be a big voltage drop.  Still, I don't like them, and I'm pretty good with a soldering iron.

My harness is a U shape of 14ga wire.  Each speed control is fed by 20ga wire.  I think it looks good, and it keeps the high amperage stuff away from the signal wires.  This setup still needs a few more zip ties.


It almost looks alive here.  Standing on it's tippy toes.  Here we are programming it for the first time.  Mistakes are being made as this photo was being shot.


For lack of damper balls, I have some rolled up cardboard and zip ties holding the "x" frame to the lower pod.  So for now the joint is rigid.  The receiver doesn't care if it gets shaken, so I mounted that on top.


I really like how the back end turned out.  There's an XT60 connector on there because that's what SwitchElectrican had on hand.  I use Deans connectors for the most part.  I'll be swapping that as soon as I get this thing home.


Testing the quadcopter didn't go very well.  Every time I got the throttle high enough to have it fly, it would sort of respond to inputs, then flip over.  Faster than I could do anything about it the heli was on it's top.

This happened three times.  I ate two props the first time, and another prop the second time.  And for the third time around, we flew on top of a towel, which saved the props...

The speed at which the thing was flipping made me think the thing was feeding back into itself wrong.  We sat down and watched a video on how to set up the Naze32.  And while we learned a bit from it, such as what "angle" and "horizon" modes were, that didn't seem to pin down why the thing was inverting so quickly.

And then we took a close look at the setup page.  Both SwitchElectrician and I had our boards in non-standard directions.  So any time the board tried to tip, the controller tried to compensate in a wrong direction.

Once we sorted out the proper directions, I was able to lift off and hover the thing.  However, due to the time of night, I wasn't able to really take it for a flight.

My advice to you, is make sure that your board knows what direction it's in on your airframe, and the motions you make with the airframe match what you see on the screen.


Oh look the quadcopter is home.  It needs a name.  I'm open to suggestions.


Next time, the quadcopter will get it's FPV rig, and it's 720p video camera mount.

Wednesday, November 26, 2014

Building a quadcopter: finding out what's missing.

A couple weeks ago, a youtube video surfaced of people racing quadcopters through the woods. Well, here's the video.

Kinda exciting isn't it? But what does a setup like that cost? How much effort would it take to do.  My buddy SwitchElectrician said he wanted to do it.  I...  well couldn't resist. 

I did some digging, and found a quad frame that looked good to me.  He and I both bought this:
http://hobbyking.com/hobbyking/store/__65245__Hobbyking_X_Factor_230mm_Quad_Copter_Super_Frame.html

 It's a good looking platform to me.  A solid X shape with a pod suspended on anti vibration balls.  The controller boards don't like vibration, so isolation is a good thing.  Amusingly, it's on the expensive end of quadcopter frames, at an astounding $20. 

Orders were placed.  Items were shipped.  SwitchElectrican and I both got our quad "kits" within a week.


Look, it's a flat pack Quadcopter.

The kit looks pretty complete.  Lets dig in.

SwitchElectrican had contacted me, and told me that his was missing some parts.  I was hoping mine wasn't going to be missing those bits.  So I start digging, and the disappointment sets in. 

You'll notice that the only paper in there is the little business card, with the picture of the quad on it.  There are no instructions, and that kinda matters on this thing, as we'll get to later.  And no damper balls. 

So I started with the bad, lets cover the good.  The aluminum standoffs are all perfect.  The screws and standoffs have good threads on them.  The screws are of high quality.  The milling of the FRP is almost flawless.  Suffice it to say, I'd buy this kit again, and again, and recommend it to others.
 

The bottom plate is some very thin fiberglass.  It's downright floppy.  But as you can see, it's got nice sharp edges everywhere, and no fuzzy bits like you'd get from a dull cutter.  I couldn't resist starting the assembly.  With eight standoffs, this should end up being a very rigid pod.
 After assembling the pod, I found that the top plate goes on the pod just one way.  This is where a manual would have been handy.  I think it would also help to dictate which side your camera should be mounted on.  

I couldn't help but throw a motor on, and a speed control, just to see what it looked like.  For now the build is stalled until I get the damper balls in. 
 
Next update should be the completed build, and the first hover. 

Thursday, November 6, 2014

Stinky stuff from China?


I love getting new stuff in the mail.  This time it was a stack of protoboards from China.  When I opened the package though, I was struck by the smell.  It smells like a zoo.  Weird...  Oh well, I get to build circuits tonight.

Thursday, October 23, 2014

Why must Android be this way? Battery managment as a lifestyle....

TL;DR: Android apps are getting bloated.  Developers aren't paying attention to android being a mobile platform and are abusing memory, cpu and battery.  How can we solve this?  How can we track it easily?

Android talks to me.  What android stands for, and represents, makes me feel a bit better about the world.  It's unlikely I'll be switching platforms anytime.  (Yes, that's a hard stop there.)  Android also upsets me on weekly basis.  It's becoming tiresome...  I just want my battery to last.  And I want apps I open to stay open. 

My first android phone was a T-Mobile G1.  For those who are new to smartphones, it was the first android phone released to the mass market.  I still have it.  It's still a good phone.  But it's also where I first learned that battery management was in my hands.  I installed a AOL instant messenger client, and flattened my battery in a couple hours. 

Every so often, apps would close that I intended to keep open.  Especially while listening to podcasts.  And while using navigation. 

The G1 had a very simple suite of software on it.  Managing what was using data, and what was waking the phone, wasn't very difficult.  Within a week or three I had the bad apps removed, and I was getting at most of a day from the stock battery.  Those were some hard learned lessons, and watching a talk from Google about gaming and battery usage really crystallized things for me. 

But that was a world of 20 or 30 apps, and a mostly vanilla install on a simple phone.  But, time was passing, my 384mhz chip wasn't keeping up.  And as programs updated, they got more and more bloated. 

As soon as it came out, I moved to a T-mobile G2 (HTC Vision to the rest of you.)  I bought it knowing I was going to need and extended battery.  With lessons learned on my G1, keeping the battery life reasonable on the phone wasn't a stressfull experience.  It was rare that a hung process caused the phone to stay at high load, and cook the battery.  But those days did start to get more frequent. 

The new phone took care of my podcast program dropping out.  And navigation wasn't dieing anymore.  At least at first.  The longer I had the phone, the more often my podcast app would just shut off.  The MP3 player would do so too. I just want my audio ... is that to much to ask?

Sadly the G2 was a slow-ish dual core chip.  About two years ago, I switched to a Samsung Galaxy S Relay.  (Can you tell I like my keyboards?)  While at first, it's battery life was just "ok."  The music player, and my podcast app were working great.  And it would generally get me through the day, a little bit of gaming could leave me phone-less by mid afternoon. 

Again, I got an extended battery.  This really helped the situation.  As the stock battery on the Relay is really quite small, and it's a phone that can draw several watts under load.  And this is where the story really turns south. 

My phone's battery life, even with the extended battery, was really only about a day.  Then one week, my phone became useless.  Suddenly my phone's battery life was down to 8 hours.  And the phone was hot.  Like, OSHA issue, hot.  Like puffed two batteries hot.   I called T-Mobile.  They had no idea.  I ended up taking it to the internet at large. 

The "internet at large" is where I found out about some moderately upsetting things.  In Windows, and MacOS, there are utilities built in that let you quite effectively manage your applications.  Utilities that let you find out what, and where, is eating your CPU, Memory, and by proxy, your battery.  Tracking that sort of information in Android is.. difficult. 

I was introduced to Wakelock Detector, and SystemCleanup.  "Needing those at all" is a problem.  But the fact they're out there did provide me with options. 

Through some testing, I found that the application that was burning my battery was the latest update to T-Mobiles app.  The one that's supposed to help me manage my account, was the one that was locking my cpu to full speed and causing me to destroy batteries. 

Between Wakelock Detector, and SystemCleanup, I was able to remove, and kill, applications that were sucking up CPU and providing me no utility.  In the end, my phone's battery was able to give me a reliable 80 hours of normal phone usage.  I was proud of my work.  I was enjoying a phone that stayed cool, played my podcasts and music, and did navigation when I needed it. 

Then the updates came.  As each app updates, they seem to get worse and worse.  And apps that have no reason to suck up CPU time, wake the phone, and cause my battery to die.  For example, Amazon Marketplace.  I have nothing through amazon on my phone, yet with it's latest update, it knocked 20 solid hours of runtime off my phone! 

I wish there were some way of dealing with this.  I had the phone of my dreams just a few weeks ago.  And now I have a phone that is down to a ~30 hour runtime.  Perhaps the walls of the android marketplace need to be a little higher.  Maybe OS controls need to be tighter.  "No, you can't run in the background." should be an option.  And CPU and memory management need to be easier to get to. 

And... in the last weeks.. I can no longer run my podcast app and strava at the same time.  Both apps updated, and it appears one kicks the other out of active memory. 

This can be fixed.  I know it... 

Thursday, August 28, 2014

Parked in front of a Microsoft data center

So, I don't have a "usual" place to ride on training rides.  Last night my wandering took me past the Microsoft data center that's just off of 294.  I got this really weird feeling I was being watched as I took the picture....

Happily, my riding has been paying dividends.  The Garmin 305 is doing it's job, and I've got a goal speed to match, beat, and flog myself when I don't.  Between the speedo, and strava segments I'm putting on watts rather quickly.  If not losing pounds. 

Back to the DC though.  It's a huge facility.  The transformers that power the place, are larger than my house.  and have blast walls between them so they don't blow up the neighbor if one does fail.