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3D Robotics

Last week to drop an egg!

Posted by Chris Anderson on August 30, 2010 at 4:30pm
3689367267?profile=originalThe current T3 competition (egg drop round) closes next Sunday, and so far we've only got one successful entry! (Mark Griffith, whose admirable splat is at right) I know several of you have tried runs without success so far, but this is your reminder to give it one more go this week.

Jason Short has made it easy for ArduPilot users. In the Events tab of 2.7, there is an example of egg-drop code that even has an equation to calculate the proper distance from the target. It assumes you've added Channel 4 control to your ArduPilot. Just set a waypoint for your egg (it's waypoint 3 in the sample code below), hook Channel 4 to a servo that releases the egg, and start dropping!



"void mediumLoop_event(void)
{
/*
float temp = (float)(current_loc.alt - home.alt) * .01;
egg_dist = sqrt(temp / 4.903) * (float)ground_speed *.01;

if(wp_index == 3){
wp_radius = 10;
if(wp_distance < egg_dist){
servo_out[CH_RUDDER] = PAYLOAD_OPEN;
}
}else{
wp_radius = 20;
servo_out[CH_RUDDER] = PAYLOAD_CLOSED;
}
*/
}
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Developer

Choose your equipment carefully.

Posted by Michael Smith on August 30, 2010 at 3:29pm
With the profusion of low-cost components available today, it's tempting to pick the cheapest one that looks like it will do the job and not stop to think too hard about how well it's going to work. After all, if it's for sale and other people are using it, it must be OK, right?

Consider this post by the respected DIY ESC developer Takao Shimizu, talking about a low cost controller available from a popular vendor:


The money quote:

But, when it's over the current (>2A), then the output voltage goes up to the input voltage(11.4V).

Read that carefully: if you overload the ESC (and 2A isn't that much of a load), your 5V supply suddenly becomes an 11.4V (or higher) supply. Think about how much you have invested in your receiver, servos, autopilot, GPS, OSD, camera(s), etc. Many (most) would be destroyed more or less instantly by a surge of that kind.

It's not just power supplies, though. Cheap servos are tempting too, but again they represent a single point of failure for your aircraft. If you're just building a foamie with an anticipated flying life of a few months, you might be willing to accept the occasional failure and early demise, but if you're flying several hundred dollars worth of gear, a few bucks more for decent servos is a much better investment.
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DIY Reflow Soldering - Ready for Pizza?

Posted by pixhawk on August 30, 2010 at 2:00pm

satrap-formello.jpg

Solder yourself in a pizza oven! While we're still waiting for the last quotes to get pxIMU ready for the batch production, we'd like to share how we build the prototypes ourselves. Of course pxIMU will come fully assembled, this guide is just intended for those who want to tinker with their own electronics or want to assemble one of our bare PCBs.

It is actually quite easy and cheap, and all you need is a pizza oven and an oven thermometer. We are already working on the new pxServo board, which will have servo outputs on standard servo ports and a connector for the ArduPilot / DIYDrones GPS modules. It will be also available with a 5V / 2.25A (12.5W) power module mounted, but still be smaller than pxPower. This combination should satisfy all user needs. This tutorial was written with delicate ICs like gyroscopes, accelemeters and magnetometers in mind. We had good success and zero failure so far with the temperature curves from our tutorial.
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Novel means of quadrotor control / adjust

Posted by Tim O'Brien on August 28, 2010 at 11:11pm

Here's the demo of my gamecube remote controlling my quad. Newly implemented is the ability to adjust the PID.P value on the field using just the remote.


This method can be implemented with the analog remotes most people use. I've got another remote that uses only analog sticks to drive a menu system. Something similar could be done for the main AeroQuad project if anyone is interested.


The idea was that I wanted a durable, reliable, ergonomic, economical, and digital remote to fly my quadcopter. I started at gamestop since I don't own a gamecube. Using with Andrew Brown's code, J.Ward's page as reference, and a logic analyzer I was able to get a gamecube interface working on 8mhz and 16mhz cpus (albeit with pretty messy code).


More info on the quad design is on my site here.

My publicly viewable svn repo is here on my server.

Pictures:


quad03-_MG_1296-2010-04-18_700.jpg

quad-gc-_MG_3303_2010-05-18_700.jpg

quad-gc-_MG_3339_2010-05-18_700.jpg

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Moderator

HG3 the era of quad variable pitch has begun!

Posted by Roberto Navoni on August 28, 2010 at 2:08pm

Particolare%20passo%20L.jpg


Multipilot Board support Hg3 Variable Pitch Mega Quadcopter actualy I'm implementing the support of HG3 (Variable Pitch Quad) to new Arducopter firmware. The last flight had doing with Aeroquad 1.5

This is last post from Pipposoft as lot of work this is a new version of HG3.2 Variable Pitch Propeller.
"
Between job and family commitments
although slow, here's some special preview of the new HG3 V2 ...
... To see it looking good, but ... fly?
leaving us with this doubt, all for now.

Pipposoft
"

This is old version of HG3

4373218270_45578d8746.jpg



For full story FoxTeam:
http://www.virtualrobotix.com/profiles/blogs/hg3-the-era-of-quad-variable
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The journey begins

Posted by Ritchie on August 28, 2010 at 12:00pm
For my first post I thought I'd give back to the community (and edit later to add anything else I can do).

Viability spreadsheet

I'm pretty new to RC planes although I have had a JP Zagi for years but with it being unpowered I'm at the mercy of the wind and I'm still pretty jittery. Seeing the DIY Drones setup I thought it would help me become a bit more competent but instead I bought an EasyStar and new system to have fun with the electronics instead and my Zagi will be my crash craft in free air anyway :D

UAV setup:
  • Futaba 6EX Tx and Rx
  • Multiplex EasyStar
  • Ardupilot Mega
  • Ardupilot Mega IMU (aka Oil Pan)
  • MediaTek GPS module
  • eTronix 40A ESC
  • Hacker A30-16M
  • Overlander 3S 2200mAH 11.1v LiPO
I'll document my build as best as I can to show the pitfalls :D so others do not copy me.
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Indoor UAV - 3D position estimation

Posted by Leon on August 28, 2010 at 9:00am


Watch on Dailymotion

Hi!

I am currently working on 3D position and attitude etimation of my indoor drone. I use a 6 Dof IMU, a 3D magnetometer, and 4 sonars (Devantech).

The position estimation is not yet accurate (still bugs), but I am working to improve it. I also have lot of problems with the magnetometer. All the computation are done on the drone. I just use Matlab for visualization.

The drone is still manually piloted.

My intention is to make my drone navigate autonomously in a simple indoor environment.

A short demo video is above:


A quick description of my drone:

http://www.diydrones.com/forum/topics/bob4-indoor-autonomous

Leon - french hobbyist

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How to setup an Overo to work with your AP -- This is just a quick run down even though a long post

Posted by Jeremy on August 28, 2010 at 3:00am

The gumstix overo is literally the size of a stick of gum.

This will show BASIC functionality of how to get the UAV DevBoard and the ArduPilot working. The rest is up to your imagination and the recipes you come up with and the add ons you want as well. I am sure there may be cleaner and better ways to interface the two but this was the easiest for me to be able to get the functions on board the plane i needed.

I will be showing you the ways I was able to use my gumstix overo fire and summit expansion board with my AP's. Tested with both the UDB V2 and ardupilot with v2 shield and xyz sensors

First and foremost you will want to make sure you have properly built and setup your build environment for the gumstix overo. You will also want to make sure you have setup your user.collection section properly and copy over the entire linux folder from the OpenEmbedded recipe selections. This way once you setup the kernel config your defconfig file will always stay the way you set it up. I will only discuss changes I made that pertain to getting the AP and the overo setup. A tip on everything from here on out is to make sure your build environment is setup and WORKING properly. This was not simple for me and took a long time to fine tune, and the build chain breaks all the time. Also my other tip is once you have a version of the branch your on you like make sure you make a branch from that config in case your next git pull breaks something. Which trust me happens way more than you want.

Once you have that all done and setup you will first want to just build a basic image:
bitbake omap3-console-image
By doing this you build everything you will need and the kernel will get built. Grab a drink or go do something else it will take a long time even with a fast internet connection the first time.
There are many kernels to chose from depending on what you want to do with your setup and to set the preferred kernel version in your overo.conf file you will want to add this line to the file:
PREFERRED_PROVIDER_linux_omap3 = "2.6.32"
Now if you want to choose a different kernel make sure you change accordingly.

Once you have built the kernel you will want to go in and customize it. The way you want to do that is through bitbake:
bitbake -c menuconfig linux_omap3_2.6.32 * I am currently running the psp kernel
Technically you do not need to reconfigure the kernel but I went in and added all i2c debugging and options that there were so as to make sure my kernel had anything it would need while working on this. I would recommend you do the same as well just so you can make sure as you go and add things on you have any functionality you need. Or say if you know future needs you want to add in you might as well set them up now so you have less chance of reconfiguring the kernel again later, other things to keep in mind are if you want to use a USB camera you will need to make sure you configure the kernel to use that as well (this is a not difficult process and if needed can post the way to get the camera and drivers and modules if your camera can work in linux should be fine). I also made sure to setup iptables properly. Also you might want to do any security configurations at this time as well. I will not go into any of that as its way out of the scope for here.

Honestly there is a ton of different things for the kernel to keep in mind and this only BRIEFLY touches what you should do. And as this is going to be long as it is, I am trying to keep this slim in case there is not really much interest.

Now you will want to take your image you made and install it either on the nand or sd card. The first time you boot your image it can take anywhere from 10 to at the longest its taken for me was 75 min for the first boot, this is first boot only. For the sd card use at least a 8gb and if you want more room for HD space you can use a thumb drive your size of choice. 60 GB for me :)
Now if you want to change an the clock you will need to get into uboot you will want to reboot your system now and once it reboots hit enter in the 5 seconds you have. Now enter the following commands:
printenv ( This will show you your current environment variables you can take note for safety sake)
setnenv (Your new boot args or so on)
saveenv
restart

For both applications you will need a SparkFun logic level converter. Was the cheapest and most recommended to me for this. You need this because the header on the overo is 1.8v

I also chose to run an XBee and this setup to transmit my telemetry info back, basically a failsafe telemetry. So to do this I made basically a y harness. So that way you can connect the overo and XBee together.



Now for connecting it:
From the summit board 40 pin header take pins 9 rx and pin 10 tx and put those on to the logic level converter on their corresponding pins on the LV side. Now you will want to run pin 26 your 1.8v and 25 ground to the LV side of the converter. Now from the HV side of the converter board you will want to run a power and ground to it, I just ran a Y cable from what would go to the XBee and hook up your power and ground to the HV side and connect the TX of your AP to the RX pin on the HV side of the converter. Bingo thats it.



There are a bunch of great pins you can access on there, I am using the serial port for the AP as well as using the i2c interface.

Now from your overo a simple connection to read the stream is as follows:
#!/usr/bin/python
import serial
import sys
import struct
if len(sys.argv) !=3:
print "Usage: UAVser.py <seria lport> <baud>
ser = serial.Serial (sys.argv[1], sys.argv[2], timeout=None)
try:
while True:
sys.stdout.write(ser.read())
sys.stdout.flush()
finally:
ser.Close()
print "Closed"

This is nothing more than a test program to make sure you can get the serial stream on your overo.


If there is enough interest I can post more information, programs and maybe other tutorials with what I have done with adding a full blown computer on board with our AP's. Though basically everything I have written are either bash scripts or C, python and perl programs and none are anything to fancy, most of what I do on board is just using existing linux programs. I log everything to a single file and that goes into a database on the overo. Then my on board programs read the data from there and fills it in appropriately to the programs, while also keeping an entire running log. I have one program that collects the info from the AP and sends it back on a dedicated wifi link to be displayed on the GS laptop. I am running a basic USB webcam running a program I wrote that uses ffmpeg for now to stream the video and I also have it place some of the telemetry stream on top as a dirty OSD type setup. The video and OSD are nothing fancy and were just because I had a camera laying around and got frustrated with some other stuff one night and got it to work "good enough" for now. I also have a 4-port powered USB hub and 2 ALFA USB wifi adapters on top of the on board wifi on the overo, as well as the on board bluetooth and a USB bluetooth adapter. Currently the CPU usage on my overo with the video and if I have everything running which is 35 separate scripts or programs wifi related and 10 bluetooth related, and the on board wifi and bluetooth both running, sqlite making its DB I have only hit a max of 67% cpu usage with the chipset running 720mhz. There are more functionalities I have added as well but most would be of no interest to people here.

You can also hook up both AP's by means of i2c but its more complex to configure and you need to add code to the AP your using if you want to get the fully functionality out of the connection and the time and hassle to do so. I have run both AP's connected in both manners (serial port & i2c). Though I am have more time with the UAV Dev Board V2 than my Ardu setup in both configurations. Also if they are wanted I can post pictures of the connections

Thanks to:
Everyone here on the site who listened to my ramblings and helped me with my problems, Chris and Morli especially! A big thanks to Bill P. for making the DevBoard and Jordi for the Ardu :) a huge special thanks goes out to my son!

Sorry for the bad pics, I dont have a good camera at this time to take pictures. I will also post more configuration pictures in a reply in a few days when the camera shows up.
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A minimum cable solution for UAV DevBoard

Posted by Riccardo Kuebler on August 27, 2010 at 2:00pm

I hate all those cables invading our little planes !
I like the german expression which describes this situation : "Kabelsalat".
I'm sorry that still no one uses PPM connections (yes, this receiver has a PPM out on channel 12).

This is then the best solution I found to minimize the amount of cables to connect the receiver to the UDB.
The connection includes 5 channels in (throttle, ailerons, elevator, rudder and autopilot mode), receiver feeding, a board to connect pan/tilt camera servos for autonomous targeting firmware, extra servos feeding.

Please note that the connections are on the bottom of the UDB board. I modified the pins to use the UDB with the Oilpan, but in this case I'm not using it (the Oilpan).

Here is the complete connection.


All the system is feeded by the throttle out / ESC BEC (already extensively tested on my Arcus, in the standard "Kabelsalat" layout).


It could be simpler but for the moment I'm using a board I already made.

I crimp all the cables myself. This way I can have the exact length I want, avoiding unuseful extra copper on board.


After that it remains to connect servos, eventually telemetry (another 3 poles cable to a logger or OSD or ...), eventually a magnetometer (4 poles cable).


Hope this will help some and stimulate some others ;)


Best regards,


Ric

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3D Robotics

Update on product availability and request for sourcing help

Posted by Chris Anderson on August 27, 2010 at 12:30pm

The effects of the recession on Asian electronics suppliers are being felt across the electronics industry, from cell phones to smaller firms like us and Sparkfun. This article explains what the root causes are, but the effect is that you're seeing more and more products going temporarily out of stock from many suppliers as we wait for components. In the case of ArduPilot Mega, which is currently out of stock, Sparkfun is waiting for a shipment of Atmega1280s to come in (ETA not currently known, but probably a matter of a couple weeks. UPDATE: Sparkfun says next week).


Our magnetometer board is also waiting for a shipment of new sensors, which will be arriving at the end of November (the good news is that we got a good deal on them by buying in massive quantities, so the price of the board will be going down).


Most other major products, such as the original ArduPilot board, the ArduPilot Mega IMU shield, ArduIMU and both the MediaTek and uBlox GPS modules are still in stock, albeit with limited inventories (act now!).


One of the components that we're having a lot of trouble sourcing is the 16MB dataflash chip that is used for on-board datalogging on the APM IMU shield. We've managed to find another 300, but at a very high price (around $15 each), so we may have to temporarily increase the price of the board by $10. Around the end of the year, we have been promised access to a larger supply, but at an even higher price!


We really don't want to pass these costs on to you and are looking for a cheaper source. Can anyone here help? The part number is AT45DB161D-SU. Does anyone know where we can get hundreds or more of them at a cost below $8 each? (We've considered other options, such as switching to micro-SD cards, but the production complexity and cost of that is no better. We are, however, willing to consider DIP chips and a socket rather than the current SMD chips)

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3D Robotics

Could this be a good UAV platform?

Posted by Chris Anderson on August 27, 2010 at 11:41am

Over at RCG, Gary, who makes these sweet birds in his workshop in Toronto, asks if if there would be interest in selling them for UAV use:

"The only electronics onboard are 3 gyros + 2 mixers. The first video is with one 4S 3000 battery, the second is with two. Payload capacity above and beyond the batteries is 2 lb. There's more info, including the 5-lb-payload eVader 750, at

http://www.gressaero.com

I think the main features of these aircraft are that they are quite robust, have lots of payload room between the props, and handle winds well.

As stated I currently make just the platforms, and have had some interest from APers. What I'd like to do is determine if they might be viable as UAVs and, if so, develop them for this segment. Specifically, I would need:
your feedback
--to determine if there is interest in the platform by itself for DIY UAVs
--info on a good autopilot for integrating in-house
--info on 3rd parties that could integrate and package
--good exposure for the end-product"
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Making of XBee-pro 868 based r/c controller

Posted by Janne Mäntyharju on August 27, 2010 at 5:30am
p1030255.jpg?w=300&h=200

I thought to gather few of my experiences while making my own
transmitter / receiver. The project started after I finally moved to 2.4
GHz technology by purchasing Hitec Aurora transmitter. One near crash
later I learned that 2.4 GHz controller and 2.4 GHz video transmitter
don’t play well together. Since here in Finland 2.4 GHz band is just
about the only band available for video without amateur radio license, I
thought to replace Aurora’s transmitter with something different.

The full story can be read here: http://antibore.wordpress.com/2010/08/27/making-of-xbee-pro-868-based-rc-controller/


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Moderator

Outback Challenge contestants

Posted by Gary Mortimer on August 27, 2010 at 3:50am
Beginning to get a fairly complete list of entrants and their D2 videos here. Am also getting more and more despondent that I did'nt go to a school like this, three entries in the contest and they all look good. These lads and lasses are the future of aviation. Best of luck to them and everybody else. Its no small task to enter a contest of this magnitude.

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In progress APM/UDB Mission Planner

Posted by Justin Wilson on August 26, 2010 at 5:00am

map3.jpg

Yet another mission planner in the works, i dont personally use either AP as i am creating my own.
As part of my dabblings i am creating an offline mapping tool etc for my GCS which i though might be useful to others. It's written in C# and leverages a fair few different map sources and caches the images to disk for offline use.

Needs .net 3.5 framework to run.

Right click to drag the map.

Grab it from here http://www.exsis.co.uk/MissionPlanner.zip

- and yes it is very much a work in progress (read full of bugs and missing fluff)

Cheers

Justin

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