Hooking up a high voltage relay

New Quad Prop Source

GemFan Props at Innov8tive Designs, look pretty nice.

Lucien says:

They are available in the following sizes: 8x4.5, 9x4.7, 10x4.5, 11x4.7 and 12x4.5. There are two different plactic formulations used for these props. The standard ones are made with a fiberglass filled ABS plastic, and are about the same stiffness as an APC Slow-Fly type prop. These are available in Black, Bright Green and Bright Orange in both normal and reverse rotation. 

The Hi-Strength versions are made from a carbon fiber filled nylon, and are about 10 times stiffer than the standard props so they really maintain their shape and airfoil under load. These props are only available in black, and have a satin finish to them.
Prices on the props are as follows, normal or reverse pitch is the same price: 

Standard Series, Black, Green or Orange:
8x4.5 - $1.50 each
9x4.7 - $1.75 each
10x4.5 - $2.00 each 

Carbon Reinforced Series, Black:
8x4.5 - $2.00 each
9x4.7 - $2.25 each
10x4.5 - $2.50 each
11x4.7 - $3.00 each
12x4.5 - $3.50 each

A whole lot of Arduino and Robotics links!

Getting ready to teach an Arduino class, so have a lot of links prepping for that.  Instead of giving the impression that this blog has forgotten about flying, I'm posting a bunch of miscellania here.

Timer Stuff

• timer1 library. This library is a collection of routines for configuring the 16 bit hardware timer called Timer1 on the ATmega168/328. There are 3 hardware timers available on the chip, and they can be configured in a variety of ways to achieve different functionality.
• SO query with a couple of answers.

AVR Programming

• Stanford notes.
• Hackaday tutorial.
• Quick Ref. check out alphabetic command and ports.

Arduino Tutorials

• Official Tutorials
• All About Circuits

Clickwheels and Diskdrive Spinners

• some forum post.
• Instructable: HDDJ: Turning an old hard disk drive into a rotary input device (video)
• code: Interfacing › HDDJ:hard drive as scrollwheel/turtable-like input

LarryBot

• larryBot – Arduino robot versions 0.1 to 0.5 lessons learned
• Obstacle avoidance Arduino robot – build your own larryBot (this one with tank treads)
• Control a DC motor with Arduino and L293D chip
• Arduino – Sonic range finder with SRF05
• Arduino: Controlling the Robot Arm

Motors

• Micro GearmotorBlocks
• Tamiya 70097 Twin-Motor Gearbox Kit
• Tamiya Gearbox Gear Ratio Comparison

DS1307 RTC Module

• ebay listing with some good information
• Arduino library to control the DS1307 RTC

Calculators

• Resistor Calculator for LEDs
• LEDCalculator.net
• ledcalc.com

Docs

• Atmel Reference

Windlock Foam Cutting Tool

A nifty foam cutting tool.

Servo Extension Arms for 3D Foamies

Great advice from Leadfeather:

• For good 3D you should have at least +- 45 degrees. 
• Cut slits only if you have stiff hinges. If they are already flexible the slits won't help.
• The longer arms are pretty typical, especially for the 5 gram servos.
• Possibly increase the servo travel if your Tx allows. Most computer radios allow you to do this in the "travel adjustment" and also in the "dual rate/expo" set up.
• For me, more throw means I use more expo for nice control response.
• For the HXT 500, Dubro 930 Micro Servo Arm XL
• For the HXT 900, Dubro 932 Micro Servo Arm XL

A couple of ideas for foamy cutout skids

• 1/64 light ply strip 9mm wide 6 in long glued with welder makes a great skid.
• a thin skin of Welder's along the bottom and front lower section of my builds.
• some strapping tape the same width or a tad wider along the edge of the lower fuse.
• Welders, covered by tape.

Quad laser motor balancing

Basic idea: attach mirror to the quad arm, shine a laser beam reflected onto a wall.  Vibrations show up as a line, when the reflected later light is a point you're perfectly balanced.  Very clever!

Layer Lens -- GoPro lens cover

This looks like it might be quite useful!  The Layer Lens is a lightweight cover that fits over the GoPro lens.  Here's the GoPro Lens Replacement Kit.

Two quad prop guards

From SDS Hobby.

From a 3D printed quadcopter. (img).

Build Update -- Arcticopter III

 Here's a followup to my original Arcticopter III build log.  I put an "experimental vehicle" label on one of the arms.  In case it gets lost, I hope this makes it slightly more that somebody might return it or at least not mess with it.  The frame is RadicalRC's Stinger kit with 600mm fiberglass arms.  This is a great kit, cheap, flexible, light, and strong.  Lots of accessory parts matched to the 10mm arms.

Motor: Hacker Style Brushless Outrunner 20-22L,  924 kV. Recommended by Davvid "dadde87" Windestål, and have been good performers both on this unit and the Arcticopter I.
Props: 10x4.5.  MontoRC props have been really good so far and need minimal balancing.  They're pretty stiff as well.
Battery: I've had good luck with Zippy 3S/2200/40Cs.  flying sedately, 25Cs weren't too bad.
Weight: 714g without battery, 915g with.

ESC: Proton 18's from Exceed Rc.  These are as far as I can tell the same pieces as the ATMEL Turnigy Plushes.  I got them with the idea of reflashing them, but haven't yet done so.  The power setup above maxes out at just under 10 amps on the bench, so for a while I was using a set of 10 amp ESCs, using the logic that full throttle for more than a couple of seconds would send the unit to points unknown.  I felt better when I saw Warthox using 10 amp ESCs!

 Here's my APM2 board.  I've mounted it on an "Eastbay Standard" foam mount, which allows me to move controllers between frames easily. You can see some mounting holes in the foam, but strapping it down with velcro works well enough for testing.

Look here to see how I cover the electronics.

The RadicalRC kit comes with wire legs, but they didn't work well for me since I take off from grass a lot, and they would sometimes stick when taking off.  I got the idea of using whiffle balls from Andreas... this is the smallest size, I think it's for practicing golf. Much merriment is made at my local flying club over this.  They zip tie very nicely to the RadicalRC motor mounts.

Here's another picture of the frame.  The receiver is a Turnigy 9x which I took out of the case.  It lightens things up a bit, and fits nicely between the upper and lower parts of the deck.  Now that everyhting's working well, I'll make some longer receiver cables and mount the unit.

Avroto 2814-11 notes

some links

• Monto RC listing
• video showing 5 lb thrust on 5S

ArudpilotMega2 + Arcticopter III maiden

will type some more later, but I'm really pleased with how it went!

Didn't intend to take any pics (the hat portion of ye olde hatcam being misplaced), but things went so well I was able to fly one-handed and hold the iphone in the other hand.  Beautiful!!

From the air.  I hadn't planned on doing this either, but things were so smooth I taped the GoPro and sent it off.  Simple mode is going to be a Godsend for arial photography.

Spinning one-handedly.  This is cut from the first video, but it's so unique and impressive I wanted to hilight it by itself.

Using a DSO Nano oscilloscope to troubleshoot APM

An oscilloscope turned out to be a pretty handy debugging tool when trying to troubleshoot my APM2 ESC problem.  Here's a shakycam showing how I used mine to verify the problem was with the ESC and not with the APM2.

APM2 indoor maiden and simple mode test

I got everything together last night and couldn't wait until the morning to go out, so I took a quick flight in the basement.  Stability was pretty good.  I made a quick video of simple mode too.

The Unbearable Lightness of Universal Serial Busses

 Here are the flavors of USB cables I've got.  From the lower right, going clockwise:

• Apple iPhone
• proprietary -- Casio Camera
• Micro A (?)- Ardupilot Mega 2
• Type B -- Arduino Uno
• proprietary -- Panasonic Lumix camera
• FTDI programmer -- Arduino [*]
• mini-B lots and lots of stuff
• update: AVR programmer

Fortunately, the computer end of these cables are all the same, classic Type A!

[*] The FTDI adaptor probably shouldn't count, since it connects to a Mini-B cable, but it's a serial thing I have around.  Of course if I mention the FTDI programmer I should also mention the AVR programmer for completeness.  It comes in two flavors as well; 10 pin and 6 pin.

Here's a diagram from Wikipedia, identifying the various types of USB connectors. Here's another good page from a cable vendor.

Here's the AVR Programmer from Hobby King.  They sell it for their KK Multicopter board.  It's nice an inexpensive, and comes with both a 10-pin and 6-pin cable.  I have one from ebay, and you have to jigger your own 10-pin to 6-pin conversion.





Update: now added a lightning connector for iphone 5.

DS1307 Real Time Clock

Here's some notes on a real time clock.  I'm not so much interested in knowing the time, but it uses I2C to communicate and I've been looking for something relatively simple to try I2C.

• geiliable-store listing
• i.control listing
• technical notes and arduino library

Quad EPS blade protection

The website is down now, but here's a quad with an eps blade guard.  The guard is sold separately as well.  It's four circular pieces with straight edged that attach together.

It would be great to be able to provision a homemade quad with something like this.

DSO Nano 2 Oscilloscope notes

Santa just arrived from a side trip to Hong Kong and dropped off my new oscilloscope.  It's pretty low-end, but I already used it to solve a problem with my new Ardupilot 2 board, so no complaint from me!






Here's some links for the thing:

• product page at seedstudio.com
• product manual (pdf)
• wiki docs
• forum
• early review, linked on hackaday

Handy Glue Tip

 Here's something I did for my opened glue containers that have made them last longer and make less of a mess.

I have a box for all glues and adhesives... I put a piece of old foam in the bottom, and made a few holes and slots to hold opened containers with the opening down.

Here's a shot of the holes.  I think I made the round ones with a drill bit, and just hand-cut the slots to be more or less the right size.

xbee attempted unbricking and troubleshooting

xbee not working... contacted diydrones store, they recommended starting with unbricking procedure here.

Here's shakycam documentation of the procedure.  It's not working, so suspecting other xbee problem.

asd

CF Reinforcement for Skywalker Wings

Here's a few notes from the Skywalker thread on RCG about reinforcing the Skywalker wings.  Daemon is one of the masters there.

Basic Idea:

• Cut four 36'' ribbons, two pieces for each wing
• Cut into top and bottom of wing, one directly above the other.
• Glue in edgewise.
• Size: 0.8x6mm

Do the same to the vertical stabilizer.

Daemon describes it:

I use a long straight edge and X-acto blade to cut the slot using my finger on the side of the blade as a depth gauge (something you can't do with a soldering iron tip) and then expand the slot slightly with the tip of a screwdriver.  0.8x6mm ribbon spar installed edgewise into the wing on the bottom. Another one just like it on top.

Here's a flight with the reinforced wings:

ArduPilot Mega 2, Initial install notes

Initial install went well.

• APM quick start here.
• Need to install a Windows driver, here.
• Mac seems to need no installation, using /dev/tty.usbmodem621
• On mac, be sure and set "Carriage Return" line ending.

H Gantry design

I was listening to the crashcast, and Crash was interviewing the phlatprinter guys.  They're working on a new device, which will use an "H Gantry" design.  It sounded pretty intriguing, so I googled it.  The basic idea is that two motors control a full x/y coordinate range, while not carrying the motors on the gantry.  This makes the gantry more stable, since it's not having to carry the extra weight.  In addition, the crossbar is supported on both ends.

Here's a commercial product that uses an H Gantry.  It's apparently a well-known technique and patents have expired.

And here's a frame showing the mechanism a bit more clearly.  If both motors turn at the same rate, motion is in the X axis.  If only one motor turns, motion is in the Y axis.  Turning both motors produces motion on both axes.

My Farm Fresh Quad Helmet

Here's how I attached a vegetable container from the supermarket to act as the cover for the Arcticopter 4.  I used these standoffs:

Nylon 6/6 Male-Female Standoff 4-40
1/2" Body Length,
3/16" Male and Female Thread Lengths,
White (Pack of 100)
http://www.amazon.com/gp/product/B00...ms_ohs_product

Even though the vegetable container is very thin, the standoffs keep the surface taut.  If you tap on the top it will reverberate like a drum head.

I attached the standoffs to the frame, and colored the tops with a Sharpie to align the holes. I handheld a drill bit to cut the holes in the plastic.

 4/40 bolts attach the stack of standoffs to the frame.  This stack is 1.5 inches, but I think you could double that and still be reasonably stable.

One nice feature of the nylon threads is that they will break before anything else.  If you break the threads off of a standoff, it becomes a perfect candidate for being the top screw.

I put a piece of blue tape on the back to block off the green LED, which I found to be too bright in the evening.  I added a 3-LED strip plugged into the balance port which works pretty well: visible without being blinding.

Some Spectrum Analysis and RF Resources from Agilent

arocholl reports:

Agilent is starting a webcast series of sessions about Spectrum Analysis and RF basics. It may be of interest of (most) RF Explorer users and RF enthusiast out there.
RF Back to Basics: Part 1 - Signal Analysis on Jan 25, 2012. 

For those of you who don't know, Agilent is the spinoff of HP for testing instruments and RF devices, a worldwide reference in RF for many decades. Besides that, they are the actual guys implementing the closest vision Bill and Dave had about their company when they created HP in the 30's, nothing close to main HP brand these days.

I recommend all the Agilent general guide I recommended to many people already. The link may get invalid anytime as it is internal to Agilent, but if it doesn't work just look for the famous "Application Note 150", the "5952-0292EN.pdf" document or simply "Spectrum Analysis Basics" within the Agilent site.

The Application Note 150 seems to be very well known.  I've downloaded it and started reading it. A lot of it's going over my head so far!

Ritewing Zephyr II + Ardupilot Maiden

Great success with Andreas' Zii/APM combination.  Flew beautifully, APM control was good, able to tune things in the air. All around a great success and left everyone feeling very pleased.  Andreas has named it Beast of Kandahar.

We flew with two batteries... 3S/5000, and then a 4S/3000.  The 3S seems to provide plenty of power -- enough to accelerate straight up. Andreas had also just upgraded the power system to:

    NTM Prop Drive 35-36A 1800
    Turnigy Trust 70A
    10x6 prop

Ground Video. This contains most of the flying modes, takeoffs, landings, and low passes.  I'll make a trimmed down version later if this one seems repetitive.

Airborne Video.

The IOCCC Flight Simulator

"The IOCCC Flight Simulator was the winning entry in the 1998 International Obfuscated C Code Contest. It is a flight simulator in under 2 kilobytes of code, complete with relatively accurate 6-degree-of-freedom dynamics, loadable wireframe scenery, and a small instrument panel.

IOCCC Flight Simulator runs on Unix-like systems with X Windows. As per contest rules, it is in the public domain."

Here's the source code:

Adding Failsafe to the Turnigy 9x transmitter with Autopilot

some quick notes:

Problem

The Turnigy 9x doesn't have a failsafe function when used with the 2.4ghz receiver.  Instead, when the radio signal is lost, the receiver "freezes" all channel signals to the last received value.

Idea

Add a heartbeat function.

Transmitter

Pick a channel, alternate between high and low PWM signals over some period.  As a concrete example, on channel 7 transmit a 1200 ms followed by an 1800 mhz signal, each for 1000 ms.

We can upgrade the Turnigy 9x to use er9x and add the code there.

Autopilot

In the arduino software, we can add a check in the 1 hz event loop.  Compare the current values with the previous values, and save the current values for the next check.  If after some number of comparisons we don't detect a change in any values, invoke the failsafe routine.

Notes

• Is the timing fine-grained enough?  If not, we can increase the frequency of the checking rate.
• Open source is wonderful.

Update: some discussion of this idea over at the 9x forums.

Microdan motor for EZ* and related planes

From the EZ* thread on rcgroups, somebody pointed out the Microdan 2505 2535KV motor as a really good (light weight, high thrust) upgrade for EZ* and similar planes.  Apparently several of the EZ* gurus use this motor.  Definitely in the high end, both in terms of performance and price. I will pull out the numbers on the Grayson upgrade I did for comparison.

    weight: 34g, cost $55

    APC 5x5, 21175rpm, 10.9V, 22A, 22oz thrust.
    APC 6x4, 19900rpm, 10.7V, 25A, 25oz thrust.
    APC 7x4, 16300rpm, 10.2V, 36A, 36oz thrust.
    APC 7x5, 15200rpm, 10.1V, 40A, 36oz thrust.

Microdan has a video of it flying in a Hawk Sky:

The Birth of Arduino

Here's an article about how the Arduino was born, and why it's called Arduino.

Elevon Gyro Stabilization

Scott Page has an interesting post on rcgroups where he has mounted gyros on a superfly.

It seems like this couldn't be done without moving the elevon mixing onto the plane, since there's not a direct correlation between axial pitch and roll movement and the control surfaces.  The trick is to put two gyros mounted at 45 degrees relative to the front of the plane, and connect the gyros to the servos on the opposite side of the frame.

By doing this, both servos react to pitch and roll, and feed their corrections to the proper (opposite) elevon.

He put a video up with the results of his experiments.  He also talks about rate and AVCS (heading hold) modes and their use in fixed wing flight.  Executive summary: use rate.

My SparkFun Signature Edition Solder Fan

 So after looking around for some fans for a solder fume extractor, I came across some old PCs being recycled. I took out one of the PC cooling fans and tried that... it worked so well that it would scoot across the table under its own power!  So, I opened up one of the power supplies and removed the fan... it seems like the perfect size for a benchtop solder fan.  I hotglued it onto a piece of cardboard I cut out of an old SparkFun box I had sitting around.  Instant class and DIY cred at no extra charge!

For power, I attached a JST-RCY connector so I could power i from one of the small LiPo batteries I keep on my bench.  The fan uses .5A, so the battery in the picture will keep the fan going for two hours without problem. I measured this with my watt meter.  If you are doing anything with RC or motors you should have one.

If I would have had a spare 3-pin or 4-pin JST-XH I would have used that, so that it could have been powered off of any battery's balance port.

Here it is in action, shot with genuine shakycam:

Troubleshooting my xbee

Here's the system I've got:

https://store.diydrones.com/Xbee_Telemetry_kit_p/kt-telemetry-xbee.htm

It's got an XtreamBee Board, an   XtreamBee USB Adapter, a matched pair of xbee modules, and all the bits needed to get things set up.

It was working before:

http://eastbay-rc.blogspot.com/2011/10/first-test-of-apm-auto-mode-drone.html
http://eastbay-rc.blogspot.com/2011/10/xbee-apm-overview.html

And now it's not working.

symptom: The blue power light comes on on both sides, but the Rx/Tx lights don't come one, and the ground station can't make a connection.

I went ahead and fixed the problem I had where the xbee was soldered inside the socket.  You can see one of the pins has a glob of solder on the side.  It was obvious which pin it would be, as the connection for the socket had a "sucked in" look instead of a "dimpled hershey kiss" look, from where the solder had been pulled into the socket.  Heating the socket leg from the bottom allowed the xbee to be pulled out nicely.

  This allowed me to get both xbee modules attached to the PC and get this information, which seems to verify that the two xbee units are functional (at least in talking to the PC), and that the xbee pro unit is likewise functional.

Likewise, both xbee modules respond to +++ and AT commands from a terminal session.

So, I'm reasonably confident that those three pieces are OK.  What to do next?  How to verify the xtremebee board?



I'm going to solder some new headers onto the xbee remote carrier, although testing the continuity with a multimeter showed that the pins were all making contact.

I can't find anybody that's a real xbee guru to advise me on this.  If I ever get these working again, I am going to really study these things until I understand them really well.  My xbee skillz will be my ticket to fame and fortune!

er9x upgrade notes

Prompted by their KK quadcopter board, HobbyKing is now stocking an AVR programmer. It looks like this might be good for for upgrading their Turnigy 9x radio as well.

I'm going to gird my loins (such as they are) and give it a go.  I'll update later, but here's a few links on doing this. All of them are by Richard Mrázek, the Michaelangelo of er9x.

Cable Installation


    cable installation video.
    written instructions.
    photos of upgrade.

Software Installation

    er9x home page
    eePe, the er9x simulator.