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Palm GCS Continued

Posted by Marc Daniels on May 20, 2010 at 8:05am
There is no RC TX or RX in my setup.

The XBee is a Pro, 900Mhz, and it I found it isn't the baud rate that is most important like some have suggested. At first I attempted to use the Xbee like a RC TX/RX sending channel updates at 50HZ and the result was 'latency'. This was caused by the buffers of the XBees filling faster then they were emptied, so what I was seeing was data up to a half a second old.

What does work is to send the least amount of data needed at a rate the Xbee can both process the incoming stream and output the stream. My latest version only sends channel changes to the airborne XBee and the airborne xbee sends channel positions at 20hz. Even when moving the sticks rapidly, the channel changes move the servos good resolution and no latency. The channel positions and expected positions are compare in the GCS and differences result in the GCS resending a servo position. So far I haven't recorded a single instance where the resend was needed.

To keep the xbee workload down (and latency to a minimum) all data is transmitted in binary. The largest packet of data that is sent from the airborne xbee is only 26 bytes big. Since the xbee's PAN ID handle the interference I only have a short preamble (!!!), a one byte Unit ID (for multiple airborne units), and a one byte packet id. The airborne xbee sends 2 types of packets, fast changing data (channel+attitude ) at 20hz, and slow changing data (way point changes+battery voltage+GPS Fix type+GPS Satelites) . This simple protocol seems to work and pose minimal overhead to the Palm and Arduino's. The Palm development software is nice in that the serial stream reader is type specific so once a preamble is detected, reading the packet data into variable is as easy as:

ss.read aMode
ss.read aRoll
ss.read aPitch
ss.read aThrottle
ss.read aLatitude
ss.read aLongitude
ss.read aAltitude
ss.read aRollAttitude
ss.read aPitchAttitude
ss.read aGroundSpeed
ss.read aAirSpeed
ss.read aCourse
ss.read aClimbRate
ss.read aRSSI
ss.read aFuel
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Palm GCS

Posted by Marc Daniels on May 19, 2010 at 10:48pm
I've been toying with this design for a few weeks and thought I'd post it. I'm using a Palm Vx, Arduino Mega, and XBee Pro for a ground control station. It's pretty rough at the moment. The airborne portion is made up of a ArduPilot Mega beta and a XBee pro. After building a airborne system using a Turborix Satelite receiver and Arduino I decided to eliminate the 'RC' equipment from the design completely. It was surprisingly easy and the range of the XBee Pro is better than my RC equipment. Here is the ground station with a simulated signal running to it:




It is really minimal, and designed to be easily read while flying. The scroll bars are F-Fuel, C-Climb Rate, S-Air Speed, and R-Airborne Receiver Signal Strength. I tried a fully graphic horizon but couldn't see it well so switch to a simple roll and pitch indicator. The pitch indicate shows +-60 degrees, higher angles have the pitch line pegged at max. This allows me to fly looking at the Palm. The scroll bars are set to the typical range expected for the flight. I'm using an ArduIMU for stabilization and am working towards a complete fly-by-wire software before going to full auto-pilot.

Here some pictures, don't laugh :), it is a rough 'sketch'. If I ever find the time I'll move it into a nice enclosure but its tupperware for now:


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Drones to help track US border in summer

Posted by Mark Willis on May 19, 2010 at 3:09pm

On a visit to El Paso this weekend, I noticed this article on front page of the El Paso Times concerning US border drone use.

One interesting tid bit, "Perez said the Department of Homeland Security and members of Congress have been frustrated with the FAA because it has been slow in approving the department's request for the drones." Sound familiar?

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3D Robotics

Best BlimpDuino mod ever. iPad control!

Posted by Chris Anderson on May 19, 2010 at 5:30am

"New York-based BREAKFAST fitted a BlimpDuino with on-board video and wireless control system and took it out for a spin at a party to interact with the crowd. Everybody's favorite controller du jour, an iPad, was employed to orient the dirigible and act as a augmented display medium."

Plus a live onboard video feed and headlights!


[From Makezine]

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ArduIMU for Quads !

Posted by Earl on May 18, 2010 at 4:00pm
Here is my contribution using a lot of other peoples code and help.
I did find how to interface the Parallax Ping sonar sensor to the IMU board.
Jose has code but for a different sensor. I only had a Ping sensor laying around.
I also read all 8 RC channels to be able to use any for control etc.
Zip file here also.Quad_mini_1_30_rangefinderPINGch8.zip

Earl



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Cheap keychain camera

Posted by CrashingDutchman on May 18, 2010 at 12:00pm
Back in december there was this blog-post about a keychain camera. Today Hobbyking has launched a similar camera: . It does 640x480 at 30fps and co
mes with a 2GB SD card included.

RD16.jpg


Now, the camera in the blog post from December has a higher resolution than this new Turnigy camera. Hobbyking mentions that too, but says (fwiw): Other similar cameras have software AVI formatting to 720x480px,reducing clarity of the 640x480 native image from the lense. While this
sounds good on paper, it makes the movie less clear and enjoyable.


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Hobbyking 's new PPM Signal Mixer for their Head-Movement-Tracker Gyro.

Posted by CrashingDutchman on May 17, 2010 at 2:30am
Hobbyking release today a PPM Signal Mixer version B fortheir Head-Movement-Tracker Gyro. This will help people with entry level Futaba transmitter to use the HT. Basically, from what I understand from the description, it adds channels to the ppm stream generated by your transmitter. If your transmitter has 6 channels, it becomes an 8-channel TX (you need a 8 channel receiver to really use it, of course).

From the website:
PPM Signal Mixer is specifically designed for those who own low end Futaba transmitters (such as the 6EX), allowing you to also use thehead movement tracking system. And even can be used with JRtransmitters. (soon available)

This version B is designed for 6EXtransmitter which comes with 8 channels receiver.
Just connect the PPM signal mixer inbetween the Advance Head-Movement-Tracker Gyro and the Transmitter and PPM signalmixer will map new channels special for X-GYRO 1000 via the transmitter.Then it maps 2 channels, and put them after the transmitter channels,now it’s 7 CH and 8 CH, that ‘s why you need a 8CH receiver. Connect theservos to 7CH and 8CH.
Note: Only works with Futaba transmitters.

Spec.
Weight: 4g
Voltage Supply: 8V-12V

PPM-Mix-1.jpg




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3D Robotics

Tip for ArduPilot 2.6 users: disable the Z sensor for now

Posted by Chris Anderson on May 16, 2010 at 10:05pm
Jason Short and I were testing 2.6 today and discovered something funky with the Z sensor calibration (he doesn't use one; I do). Until we sort it out, it's best to disable the Z sensor. Just set this line to 0, as shown below

#define ENABLE_Z_SENSOR 0

Although the code will eventually auto-calibrate without the Z sensor, you can calibrate it immediately on the ground before flying. Just hold the plane vertically and rotate it all the way around so each window of the XY sensor gets pointed at the sky at least once. This has the effect of setting the max readings for each side (which is actually all the Z sensor does). Once you've done that you can launch and it should be calibrated right off the bat.


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Developer

Quick Post: ArduPilotMega Shield/OilPan Photos!

Posted by Jordi Muñoz on May 16, 2010 at 10:30am

Is not ready yet, has tiny mistakes, but the tweaked boards is under the last hardware performance test's , as soon as i get an answer, I will start the mass production... ETA two weeks! (Maybe sooner).

The shield can be bottom placed (oil pan) or in the top (Shield). I would suggest the bottom side so you protect the IC's and have a lower profile!

Poll: Do you prefer the Shield in Red or Blue?

See ya!









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Flight Control Board trial run. part2

Posted by Ho-Chung Chang on May 15, 2010 at 7:15pm
I had got sensor board yesterday, and assembled it to FCB. It's disappointed that GPS can not receive the satellite signal. I think maybe SC-1513 GPS module's antenna layout is difference with MSTAR GPS modules.(I don't sure.XD).

But the 6DoF IMU run very well.


Bug Fix:

1.Gps antenna layout.

2.5V-->3.3V , 3.3V --> 5V level shift modifidy.

3.Add MPXV5004 Differential PressureSensor for Airspeed.


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FPV Skywalker

Posted by iw28 on May 15, 2010 at 12:11pm
Hi


I just saw other RC FPV webshop where they also sell the new FPV Skywalker made of EPO, so if there is any of you guys who are looking after the Skywalker,,

there is the websites. lowpricerc.com and fpvhobby.com
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Remzibi OSD Ardu1.3 Firmware and Config Tool Update

Posted by Paul Mather on May 14, 2010 at 7:30pm
WiringEverything.gifRemzibi released a new version of his firmware several months ago and the config tool is now compatible. Sorry for the delay. For those who are interested, there is a rather lengthy tutorial of sorts I wrote on RCGroups about getting the Remzibi OSD to work with the ArduPilot, Optional ArduShield v2, ArduIMU v2 and the NMEA GPS that ships with Remzibi's OSD.

The thread can be found here: http://www.rcgroups.com/forums/showthread.php?t=1234310

Step 5 includes information on using the output from ArduPilot to supply GPS, pitch and roll data to the OSD. Below are a few screenshots of an EasyCAP screen and the modifications to the config tool to indicate where the moving dashes are on the OSD.

Config Tool
ConfigToolArduPilot.gif

EasyCAP
ArduPitchRollEasyCap.gif
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SKY WRITING RETURNS

Posted by Jack Crossfire on May 14, 2010 at 3:30pm
SHORT WAVE IR, GROUND VS. EMBEDDED, MARCY 2 NOTES,





Not to be outdone by Navy Aviator Heroine, Vika 1 made a UAV sky writing
video. The last video of skywriting was in 2008, using 1Hz GPS, no
barometer, & the T-Rex. It's the most technology ever thrown at a
single word. To this day, no-one else in the world has done it, believe
it or not.




Note ground station in bottom center.


SHORT WAVE IR

Also of interest are some short wave IR cameras if you're having trouble
seeing through haze. They look small enough to put on a model. If you need to know the price, you can't afford it.

http://www.sensorsinc.com/index.html


GROUND VS. EMBEDDED

Well, we've been using ground based autopilots since Fall 2008. It's
been much cheaper than embedded autopilot. Crashes don't destroy
anything expensive. Every vehicle shares the same ground based computer
& uses a real simple board. Regarding convenience, would say it's
equivalent to embedded autopilots.

You've got easy configuration, a full development environment,
potentially more neural network capability, but have an autopilot in 2
halves. Sensor acquisition & rate damping can only be done on the
airframe. Getting high bandwidth, reliable, realtime communication is
still complicated. Radios haven't evolved.

2 different runtime environments are required to do the job of 1.
Communication isn't perfect. Some data is lost & flight is not as
stable as it could be if all the data was getting through, especially
with GPS where 1 lost packet is .25 sec of data.

Now that ArduMU or ArduShield or whatever is flying quad rotors, it's
tempting to switch to that. If we were just starting now, we would have
just bought Ardu parts. The main problem is the extra stuff for
commercial RC transmitters & fixed wings we'd never use. The cost is
also still much higher & it still doesn't have C language flight paths.

Then there's the lure of 32 bit ARM. Reverting the ground based
autopilot to embedded is a lot easier with 32 bits.


MARCY 2 NOTES



Rebuilt the 900Mhz ground station radio with a single sided board after
it started getting flaky & Marcy 2's double sided board failed completely. It's still flaky.

The 900Mhz FSK chips have become too flaky to fly recently. An unknown
state change is happening on the PIC which can only be fixed by
resetting it, not the FSK chip. Other problems seem due to the
inaccuracy of home made boards. Marcy 1's flight board has been
perfect, ironically.

With all the problems with 900Mhz FSK chips, we're leaning towards
abandonning indoor projects, especially Marcy 2, & just focusing on a
large outdoor monocopter with the complete XBees, GPS, & SCP1000. Want
to fix the problems with Marcy 1 as an indoor, manually controlled
monocopter 1st.

She's leaning towards reverting to a bicopter to fit indoors, but the
advantage with monocopters is having the most airfoil in the highest
speed air for the least weight. That leads to longer wings.

Chord length & balance beam size are related. Wider chord length
requires longer balance beams. That leads to long, skinny designs.







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Fun with planes, parafoils and robots

Posted by Howard Gordon on May 14, 2010 at 9:30am
SnowflakeFigA.jpgSnowflake is a collaboration between Naval Postgraduate School and University of Alabama at Huntsville to develop single and multiple autonomously guided parafoils. The project, described in detail here, uses an Arcturus T-20 UAV to launch the parafoils and a Surveyor SVS-based robot with Inertia Labs Renegade base to autonomously locate the parafoils after landing.

We had the opportunity last week to view Snowflake field tests at CIRPAS McMillan Airfield. The Arcturus launched a pair of Snowflake parafoils from 3500-ft, and upon touchdown, the Snowflake controller transmitted GPS coordinates that were relayed to the robot. The robot then autonomously moved to the transmitted coordinates using a script written in picoC. We witnessed 3 successful UAV launch and robot retrieval cycles. Future tests will include drop of a smaller version of the Surveyor robot by parafoil.

IMGP1794.jpg
Arcturus ready to launch. Note underwing pod carrying the parafoil.

IMGP1806.jpg
Parafoil approaching the ground

IMGP1808.jpg
Robot receives parafoil GPS coordinates

IMGP1818.jpg
Robot driving through the grass to reach parafoil

IMGP1839.jpg
Arcturus approaching touchdown

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Developer

Meditek MK3329, 66 channels, 10Hz for just $34.95!

Posted by Jordi Muñoz on May 13, 2010 at 10:30pm
With my endless effort to keep everything cheap and I'm just starting (I just got a pick and place machine!). If you want a cheap GPS here is the best deal you can get, pretty good actually:

Click Here!

Features:
-Basedon MediaTek Single Chip Architecture.
-Supply from 3.3V to 5V!
-Dimension：16mm x 16mm x 6mm
-L1Frequency, C/A code, 66 channels
-High Sensitivity：Up to -165dBmtracking, superior urban performances
-Position Accuracy：< 3m CEP(50%) without SA (horizontal)
-Cold Start is under 35 seconds(Typical)
-Warm Start is under 34 seconds (Typical)
-Hot Start isunder 1 second (Typical)
-Low Power Consumption：48mA @ acquisition,37mA @ tracking
-Low shut-down current consumption：15uA, typical
-DGPS(WAAS, EGNOS, MSAS) support (optional by firmware)
-USB/UART Interface
-SupportAGPS function

You can watch it in action here, i got 9 satellites during fly, taking in consideration a 1.3Ghz@1Watt video transmitter very near to it:




The heading and the altitude is not that bad! Soon i will release an easy to solder interface board with EM-406 "like" port.
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