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I2C woes

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Stepped the wireless down to 11megabit & the range definitely increased.  It uses a lot more power because the transmitter is on longer, but the penetration is much better. 


Found another 64k of RAM on the STM32F4.  It's the fabled core coupled memory, bringing the chip up to 192k.  That increased the framerates.

640x480 color: 5fps  1.4 megabits
640x480 greyscale: 7fps   1.8 megabits
320x240 color: 23fps 2.5 megabits
320x240 greyscale: 30fps 2.5 megabits

The trick with the core coupled memory is it can't be accessed by any peripherals.  The network now needs a memcpy.  The mane benefit is there's enough RAM to have the largest buffers, all the time.  The camera can be in 320x240 greyscale for navigation, than briefly switch to 640x480 color for a photo, without having to shuffle buffers around.

There are also 320x480 & 160x240 modes.  The theory with this is a rolling shutter camera can be used in pushbroom mode, capturing a wider field of view by compressing the vertical lines.  The resolution becomes equivalent to 2 320x240 images stacked on top of each other.

320x480 greyscale: 14fps
320x480 color: 9fps

160x240 color: 30fps

160x200 is Commodore 64 resolution. 


The camera was damaged from pointing at the sun.  It didn't generate hot pixels, but made areas more blue.  Between hot air melting & sun damage, it's real fragile. 

Spending 2 days optimizing different video modes was a waste, but it might have come in handy for any job interviews.  Times have changed.  Job interviews today are straight programming tests from Google's interviewing style.  They're not interested in applications, but very specific knowledge about a programming language.  Google is presumed to be the handbook for everything.


The tasks of PWM, battery sensing, & magnetometer reading, which are the bread & butter of aviation, sure look mundane once you get video going.  The STM32F4 makes life a lot easier with pullups on all the GPIO pins & 2 32 bit timers, allowing 8 channels of 200 Hz PWM with no funky interrupt handling.

The magnetometer used in Marcy 1 & Marcy 2 was a freebie AK8975, which came at a cost.  It's sold in 32 piece minimum quantities & costs $6.  You're looking at $200 just to get started.  Almost anything is cheaper.   The HMC5883 is $4 & has an I2C interface.  It's most certain that every production run of Marcy 2's would have completely different parts.


There's actually a chance video could do the job of the magnetometer.  To be sure, Chinese toys have used video of sorts to stay in a certain horizontal position forever.

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Airframe assembly begins.

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It's been ages since I ever removed the photoresist or actively tinned anything.  Tinning would definitely make it heavier.

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That is a heavy board.  The bottom of the camera faces the leading edge, so the scanlines cover a longer distance than a single frame.

This arrangement immediately caused the RF emissions to crash I2C.

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Various attempts to defeat it failed.  Lower pullup resistors on I2c, routing the I2C away from the wifi, moving the wifi away from the motherboard didn't work.  It's just going to be limited to 40 samples/sec by the RF.  The same thing happened on Vika 1 with the XBee. 

Marcy 1 needed 112 samples/sec & got that with a long I2C cable, but a very low power radio.  Cell phones must have a lot of shielding between their I2C sensors & the RF.  The AR drone has the Wifi on the opposite side as the analog sensors.

Seem to recall having a dream about fixing I2C on this board.

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T3

...will tak place 22th to 27th May 2012 in Pałac Kultury i Nauki, Warsaw.

The exhibition will be physically located in Museum of Technology  inside this monumental building.
The Museum is recently known for organising countrywide meetings that have spin-off potential and highly technological subject.

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22.05.2012   12.00  - official opening in Museum of Technology

24.05.2012   16.00 - UAV laws and flight safety seminar for registered participants

25.05.2012   A contest for the best thesis with UAV in its research scope

26-27.05.2012 Multicopter demonstration for large public inside the museum

Note: polish official acronym for UAV is BSL (Unmanned System, Flying)

Pictured: could be like Mr Hajduk's plane with analog camera circa 1997? Low accuracy guess.


Almost all polish UAV makers will have their (small) booth. Several full-scale (maybe unequipped internally) UAVs will be on display.

Therefore if you are passing near Warsaw Central Station, let the traffic jam fade and step into the tallest building in sight.

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3D Robotics

I interviewed MIT professor Missy Cummings at the Wired Business conference in NYC a couple weeks ago and the video is now live here. She's now on temporary assignment to the Office of Naval Research awarding grants on robot medivac helicopters. 

You can see some similar 2010 research on this by Carnegie Mellon professor Sanjiv Singh in the video above:

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3D Robotics

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If you're a New Yorker subscriber you can read Nick Paumgarten's very long and well-reported article on civilian UAVs in this week's New Yorker. It quotes a lot of people including this one from me: 

"The Internet was once a military thing, but we colonized it and took away from them," Anderson told me. "Right now, drones are scary. I'd like to make them unscary. What if all the UAVs in the air don't say LAPD [Los Angeles Police Department] and, instead, say 'Pizza Hut'?"

Includes visit to Aeroenvironment and U Penn's GRASP La, home of the swarming nanoquads shown at right. 

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I wanted to analyze some data from a tlog file and figured that Excel would be the most flexible  way so I created a little utility to extract the data I was interested in and save it as a comma separated value (CSV) file. Each selected parameter is in a separate column, and Excel can open  the csv directly.

Note that it can't open the tlog file directly. You must use the Mission Planner to convert it to txt format. so:
1. From the APM Mission Planner Flight Data page select "Telemetry Logs", then "Tlog > Kml or Graph", then "Convert to Text". 

2. Select the tlog file you are interested in, and the Mission Planner will create a txt file in its log folder. 

3. Open the txt file in this program and it will parse the file and list the available parameters in the left tree control. Double click on the parameters you are interested in and they will be selected and displayed in the right tree control. If you want to remove a parameter from the selected list, double click it.

4."Save As" and provide an output file name. This will produce the csv file that you can open in Excel and plot as desired. The file will look like this, where each row was produced from one packet in the input file that contained at least one of the selected parameters.

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If you want to re-use the list of parameters you can save and re-load them from the "configure" menu. These are simple text files you can edit directly if you like.

I am not familiar with the deloyment process for C# programs, so I have placed the entire project folder here. 

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Ground station antenna mount...

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I had previously setup my video receiver and telemetry set on a tripod with a PVC "mast" to establish height and antenna separation.  Xbee on one side, video receiver on the other.  My ASUS tablet PC hung in a case on the cross-bar between the two masts.  Video runs down to a Digital-8 video tape recorder, sitting on the ground because it's weight was difficult to balance on the wooden platform between the tripod and the PVC frame.  Power is provided by an AC inverter in the SUV,

I setup the tripod right next to my SUV.

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Unfortunately, the tripod was pretty unstable.  I've had the whole assembly fall over due to wind and even with a stable tripod, the pan/tilt assemble is a weak point.  With the PVC frame it was quite top-heavy and it required me to run an AC cord out from an inverter in the cargo area to power the video recorder, tablet PC and video receiver.

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After thinking that one through a bit more, I decided to rig up an antenna mast with a magnetic base that I could mount on the roof of the SUV.  3689456363?profile=original

 

It's bigger than it looks.  I built it from 1-1/4 inch PVC rather than the 3/4 inch PVC the prior apparatus is made from.  The magnet base is about 6 inches in diameter and quite strong.  With this setup, I can get the antennas up as high as with the larger, more cumbersome tripod arrangement, but with a simpler, smaller apparatus.

 

I was able to identify a number of additional advantages:

- I can pick-up and chase an runaway plane without having to load equipment back into the SUV, maintaining video/telemety contact on the move.  This might be a bit sketchy.  I would never intentionally "operate" in this mode, but if moving the ground station (with a designated driver) will allow me to regain control, I think thats a good thing.  If I seriously ever want to do this, I'll have to examine just how strong the mount would need to be as a function of the possible speeds the SUV would be moving at.  Dirt road at the flying area - easy.  65mph on the adjacent freeway while the plane tries to fly to Tucson - not so easy.

 

- After launch, I can take a seat inside the vehicle, benefitting from AC (it gets hot here) and shade (tablet display is hard to read in bright light.) I'll have to ease into this to ensure I truly know what I'm doing here.

 

- Affords better protection to the video recorder and tablet PC.

 

- I believe that being mounted on the roof will provide the antennas a source of reflection that would benefit them in terms of additional gain.  There won't be any electrical connection to establish a true ground plane (at least not intentionally), but just reflection alone should help a bit.

I'll come back and post more photos as I actually assemble the various components onto the SUV.

 

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T3

http://www.pansa.pl/euro2012/index.php

http://ais.pansa.pl/?lang=_pl&top_menu=top_ais&left_menu=menu_ais&opis=euro2012

and in particular http://ais.pansa.pl/pliki/supplement/EP_Sup_2012_17_en.pdf

says (rougly, read details by yourself) not a single unauthorised aerial vehicle (not even RC model) since 1PM within 50km circle from stadium during the day of major meeting

plus

permanent no-fly zones in several city centres and footbal training camps of 2-3km diameter during a month.

Restrictions end rougly July 2nd.

50km cricle is quite large; you might be surprised to break the law during local filming somehwere in the village if a major match is taking place.

So forget your engineering diplomma, familiarize yourself with chips and beer then sit down patiently in order to watch the TV transmission organised by EU governments as 22 guys run around randomly spitting on the grass, or the police will be chasing you.

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Moderator

Schiebel Engineer dies in incident

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Sad breaking news.

A foreign engineer from an Austrian company was killed and two South Korean colleagues were injured Thursday when an unmanned spy drone crashed into their control vehicle during a test flight, police said.

The trio were testing the aircraft for South Korea’s military in the western port city of Incheon, police said.

“A 50-year-old foreign engineer from an Austrian company died on the spot when the S-100 drone crashed while they were controlling it remotely from inside the vehicle,” a police spokeswoman at Incheon told AFP.

http://www.suasnews.com/2012/05/15515/schiebel-s-100-crash-kills-engineer-in-south-korea/

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Moderator

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Having seen the post about football airspace restrictions thought I should add this

Smaller airframes perhaps used by drone journalists would be subject to current ANO provisions. Any part of a CAA 1:500,000 chart that is yellow is considered a built up area and therefore not suitable for UA flight. So a pilot observed flying anything outside of approved RC flying sites within the prohibited zone might expect an interview on the 13th floor at Gatwick with no biscuits. I doubt if they will go after a small boy in a park, but try them with a camera equipped anything. 

If you have any thoughts of showing off and posting some FPV videos whilst this is going on from anywhere in that red area you need your bumps read. They will prosecute you if caught no questions asked.

Unlike other parts of the world there are clear rules that you will be breaching. That always applies to the yellow bits on a CAA 1/500,000 but its if they choose to come get you.

More reading here http://www.suasnews.com/2011/03/4439/olympics-2012-airspace-restrictions/ 

Here is what the entire area looks like with restrictions of some sort or other in force.

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The CAA in the UK have been very good to unmanned aircraft types, especially those of us in the small world. Other countries still do not have regs permitting commercial flight and clear lines drawn in the sand. Lets not ruin a lovely thing.

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Skywalker #2 Camera pod

Almost finished with Skywalker fuse #2.3689456191?profile=originalI used liberal application of velcro to attached each camera.  The ContourHD also uses a removable velcro/adhesive mount.  The good part is that now I can turn the cam power on and set to record without having to remove the camera from the canopy ("cam-opy"?).  As you can see from the photo below, I cut the hatches rounded instead of following the hatch lines moulded into the fuse by the manufacturer.  This was based upon the realizing that the  sharp corners on the previous hatch weakened the structure.  After the first crash I had to glue/reinforce the structure that failed at the corners, totally shearing the foam between the canopy and the fwd/top hatch corner.  I wish I had taken pictures...3689456211?profile=originalAdded 2 video cameras and an HD camera to the pod that now comes in lieu of the foam canopy.  Below you see the fwd facing HD and video cameras.  The HD camera does NOT provide NTSC output to the video transmitter, unlike the GoPro.  Thats the primary weakness of the ContourHD (in addition to weight).  You can see here the side looking camera.  This camera, with video switching (waiting for units from nghobbies.com and flytron.com) will allow me to switch from fwd looking to side looking whenever the UAS is circling in loiter, "fly to"/guided, RTL or on command.  The aluminum mount can be bent to adjust the angle as I make some test flights.  Starting position will be 90deg. 3689456138?profile=original Looks like its going to work out well... 3689456239?profile=original

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3D Robotics

DIY Drones at 25,000 members!

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As is customary and traditional, we celebrate every new 1,000 members here and share the traffic stats. This time it's 25,000!

There were 1.4 million page views this month, which is close to a record. It just took us four weeks to get this latest 1,000 members--we're averaging about one new member every 43 minutes.

Thanks as always to all the community members who make this growth possible, and especially the moderators who approve membership applications and blog posts and otherwise answer questions and keep things ticking here. We've got about 50 moderators now, but if anyone would like to join this group, please PM me. If you've been here for a while and have been participating, you'll fit in great.

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XBee Pro 50mW RPSMA - Series 2 (ZigBee Mesh) - Sparkfun part: sku: WRL-10419, can not be used for Two-Way telemetry.

If you are looking for two way telemetry using a pair of this module “XBee XBP24BZ7”, then better do not buy it at all, I purchased one pair and suggesting, based on my findings.

For transparent serial communication between the airplane and the ground station, you need to configure one of the mudule as XBEE COORDINATOR AT" and the other one as “XBEE ROUTER AT”.

The the X-Bee configured as “COORDINATOR AT” will be at the ground station and the other one which is configured as “ROUTER AT” will be in the airplane.
My findings are;

1. The speed of data flow from Rouert AT X-Bee to Coordinator AT X-Bee is very fast and have no issue.

2. The speed of data flow from the Coordinator AT X-Bee to Router AT X-Bee is very very slow and not acceptable.

When I tried to use with APM, It was very very difficult to read and write waypoints from the ground station.
First I suspected if there could be any hardware issue in one of the X-Bee but it was clear when the problem got shifted when I swapped the configuration of the two X-Bees “XBee XBP24BZ7”

I tried on different bauds and even newer and older firmwares of this X-Bee “XBee XBP24BZ7” but same problem.

However there is no such issue in “XBee Pro 60mW Wire Antenna – Series 1 (802.15.4)” sparkfun.com/products/8742

Digi needs to take care of this issue promptly if they really want to keep this product selling.

Recorded video, describing this problem:
vimeo.com/41900865

 

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Euro 2012: restrictions for air traffic

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Hi there.

2012 UEFA European Football Championship is almost here, 8 June – 1 July. Along with this many restrictions are coming.


Starting from 15th of May aerial restrictions will ban small air traffic including aero clubs, gliders, balloons and.. RC crafts. In the 50km circle from stadiums we won't be allowed to fly even small RC planes nor copters. Forget to record some cool videos from above (legally).

In Warsaw few more tactic places will be restricted.

Such requests came from organizers of the championship so locals must obey them.

Here you can find more details (if you know Polish ;-)

Interesting fact. Black Sheep team's final movie from San Francisco is mentioned in the article. Subtitle says: "Flight like the one from Black Sheep are out of the question".

Good that my copter is still a work-in-progress. My sadness won't be so big ;-)

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In my previous post I described how to show APM telemetry data on Hitec Auroras screen. The code has now been updated to support APM2 board, though APM1 is also supported. New firmware also adds support for GPS coordinates. Only thing still not supported is GPS date and time since APM internal date format is yet to be decided.

More info here: http://antibore.wordpress.com/2012/05/10/showing-apm-telemetry-data-on-hitec-auroras-screen-revisited/

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Moderator

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Gene from RP Search Services shares some of his considerable experience with Patrick.

http://www.blogtalkradio.com/suasnews/2012/05/09/suas-search-and-rescue

If you have any ideas for people we should invite as guests then please email Patrick, patrick@suasnews.com 

We have a few ideas going forward and hope its of use to the community at large.

Cheers

Gary

Would love to hear your thoughts at http://www.facebook.com/suasnews as well.

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