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May 01 2012

New 3DR Radio Telemetry System

http://api.ning.com/files/NC4Rs-RhY6b4ikH5XnjJn9bh*76ndPaxz5IYUQccm2kH9KynI2rt3PDhou4Rt7a56oSW-jaq32tx8avBNPOvuQ__/3DRradiokitdip.jpg

The 3DR radio telemetry system looks very promising!  It is intended to be an improved replacement for xBee radios.  We ordered a set as soon as we heard about them.  With improved performance specs and compatibility with Ardupilot, these radios look like they'll be flying on the next generation of Ecosynth aircraft.

In addition to these radios being specced better than the xBees, we'll be using them with directional antennas (the one on the ground station will point towards the sky; the one on the aircraft will be pointed down towards the earth).  We've always had trouble with xBee communication; even during standard flights the xBees are spotty at best once the kopter is up in the air.  These radios should be a welcome improvement. 

Update: 3DR Radios have come in, and they have been successful in connecting the arducopter to the ground station in the lab.  A flight test will follow soon.

Oct 25 2011

WiFi 1.5-mile range: never lose signal in the forest again?

WiFi for Ecosynth?  Amped Wireless Unveils Its Professional Series High Power Repeater and Access Point with Wi-Fi Coverage Range of Up to 1.5 Miles

Amped Wireless unveils its professional long-range Wi-Fi Access Point and Repeater that provide Wi-Fi coverage for large homes, offices, building-to-building applications, open outdoor areas, boats, marinas, RVs and parks.

CHINO HILLS, Calif., Oct. 24, 2011 /PRNewswire/ -- Amped Wireless, the leading manufacturer of high-power, long-range wireless products for the home and office, adds to its successful line of Professional Series High Power Wi-Fi Solutions for indoor and outdoor applications. All Amped Wireless Professional Series High Power Wi-Fi Solutions feature a weatherproof enclosure for indoor and outdoor use, an advanced 600mW amplifier for professional Wi-Fi range, and a high-gain directional antenna to achieve strong, wireless connections up to 1.5 miles. Amped Wireless Professional Series

Jul 18 2011

XBees Again

I think I have fixed the XBees, again, maybe…

I wanted to get our tablet laptop up and running again as a Hexakopter flying machine for the field – especially since I got the new Pentax WG-1 GPS camera in the mail today (I’ll post on that soon).  This laptop had already been running Mikrokopter-Tool v1.74a, allowing us to do 3D waypoint runs, but the XBees were not functioning at all.  I also had it in my head to install a SSD hard drive in this old laptop to give it a new lease on life – what better opportunity to try a fresh setup! 

A quick note to anyone that has found their way here with their own XBee woes, we are using XBee Pro DigiMesh 900 modules.  This post discusses the (hopefully) successful configuration of a pair of XBee Pro 900’s each mounted on an Xbee Explorer USB.  In a previous post, Xbee Solutions?, I suggested that it is necessary to have an Xbee Explorer Regulated on the MK end, but it seems that may not be necessary based on the results described below.

I got all the standard drivers and software installed and running (XCTU and  UART drivers) and plugged in the suspect Xbees.  Windows 7 said it correctly installed the new hardware, but when I opened up MikroKopter Tool I could not get any XBee communication. AAAAAAAH!

Back to the internet, I found this long thread about Xbee problems that offered promise: http://forum.mikrokopter.de/topic-21969.html

Taking from the thread, I set up two XBees on the same machine in two instances of XCTU to be able to effectively range test and compare parameters. Why had I never thought of that!? I read the modem configurations from each unit – mostly noting anything that was other than the default and confirming the baud rates were set correctly.  I quickly noted that the Modem VID numbers were different and read from the help dialog: “Only radio modems with matching VIDs can communicate with each other.”  One XBee was set to the default and another was set to a specific number.  I didn’t remember making this change but decided to set them both to the same number.  The range test was now working perfectly (see post picture).  Back in Mikrokopter Tool I was back in business with wireless telemetry, but I still couldn’t transfer waypoints.  I kept getting that ‘Communication Timeout’ error.

I tried another suggestion from this  post  in the same thread and manually adjusted the Destination Addressing fields on each unit.  I noted the high and low serial numbers for each unit (SL and SH) and manually configured the  high and low destination addresses to point at each other: XBee1 DL = XBee2SL, XBee1DH = XBee2SH, and vice-versa.

I flashed these settings, booted up MikroKopter Tool and was wirelessly transferring waypoints and receiving telemetry with no problems.

Of course, now we just have to see if it’s actually going to work in the field!

Next up: playing with the GPS camera!

Jul 15 2011

First Altitude Controlled Hexakopter Flight!!!

 

This past week I've been working on flashing the new firmware to fly altitude controlled waypoints. As it turns out there was no need for the newest hardware to use the latest firmware (FC 2.1ME, BL 2.0 required). After working out some compatibility issues with the old version of MKtools, I finally was able to connect to the Hexakopter. Today we were able to do a flight test, check out the video for yourself (best in full screen hd).

Next week I plan to flash the new firmware on to the other 2 remaining Hexakopters.

 

                                                                                        Why are you reading this watch the video!

Mar 05 2011

Field Day with the 485 Class

We had a great field day with the GES 485 class on Saturday flying the Hexakopter at the Herbert Run site and developing field work and 'ground-synthing' techniques.

The weather was actually quite good for a data collection.  The sky was overcast and there was no wind, meaning that the Hexakopter was able to stay on track and the light was relatively diffuse so there are few shadows in the images.  I gave a large set of about 2000 photos to Photoscan for processing on Saturday afternoon and it is still running.  This is a great software, but I don't yet have enough of my own benchmarking data with large sets to really test out how it is going to work. I hope the point cloud looks good!

Regarding our Xbee testing, I used the MKUSB to upload waypoints, but then discovered that when I power down and then power back up to swap out the battery and plug in the wireless Xbee module I cannot read waypoints from the MK, or they are not stored on board.  But, I was able to upload waypoints wirelessly with the new Xbee configuration and the real-time telemetry communication during the flight was OK.  At least the current setup is no worse than what we had before.  More to come.

Mar 02 2011

Xbee Solutions?

Is the solution to our Xbee problems to not use them at all?

You may recall several posts and rants about our problems with Xbees, http://ecotope.org/ecosynth/blog/?tag=/XBee, and we have been actively looking for a solution.  The picture at left shows a potential new system for transferring data from the field computer to the Hexakopter on the ground and then in the air.  In this picture is the Mikrokopter MKUSB module that is used for hard-wired USB data communication between the Hexakopter and the Mikrokopter tool software; a new Sparkfun USB Explorer Regulated board; 2 Digikey Xbee Pro 900 modules; and a Sparkfun Xbee Explorer USB module.

The plan is to use the MKUSB module to upload waypoints and control settings to the Hexa prior to flight, then pop on the Xbee wireless configuration for spotty telemetry during flight.

Our problem for months now has been very unpredictable performance with the Xbees for wireless telemetry communication.  The set up was: 2 Xbee Pro 900’s both mounted to Sparkfun Xbee Explorer USB modules.  One Explorer USB was set up for USB communication with the laptop (the module shown at right in the image) and one Explorer USB had a ribbon cable soldered to it for plugging into the Hexa (image not shown).  At first, this seemed to work OK, but for some very odd reason, this set up started failing, to the point where it was impossible to wirelessly upload waypoints to the Hexa from the laptop within just a few feet of the unit.  I do not want to think about the countless hours wasted on this.

This new setup aims to 1) circumvent the need to us Xbees for mission critical steps (waypoint and configuration upload) and 2) use a different hardware configuration to attempt to re-establish successful wireless telemetry communication using Xbees during flight.

We will use the MKUSB in the field to transmit waypoints and configuration settings to the Hexa via wired communication and then use the Sparkfun / Digikey configuration shown above for getting what wireless telemetry data we can during flight (with the assumption that the Xbees will still fail or be spotty).  Sparkfun recommends this configuration over the use of 2 Explorer USB modules and we are not entirely sure why we have the configuration that we have been using.

With a leaf-off flight planned for the UMBC Herbert Run site on Saturday, I hope to have some positive results to report next week!

Nov 19 2010

XBee Pro 900 & Brushless Controller 2.0 Incompatible?

XBee, why you no connect!This week I attempted to determine the reason behind the XBee connectivity problems. With Chris’ help we tested a few things we believed that could be the cause of the problem. First we tested if the field laptop was the issue behind the connectivity problems. Using another laptop we spaced the Hexakopter and the laptop about 70m apart and sent waypoints as well as running a motor test. We were surprised when the field laptop preformed at par with the other laptop and neither lost signal through the test. After ruling out the laptop, we decided to change the XBee’s and found that the Xbee’s performed consistently regardless of which pair was used. With both tests showing complete functionality between the XBee’s we decided to fly the Hexakopter outside.

During the first test flight we had no issues with the XBee’s losing signal with the laptop. However, after the flight was completed we started getting connection issues with the XBee’s. In a last ditch effort to find the issue we tried using another Hexakopter that ran on the Brushless Controller 1.0. After running both Hexakopters for about 5 minutes, we started noticing that the Hexakopter with the BL 2.0 was getting connection errors while the other Hexakopter (runnig on BL 1.0) had no connection issues. We also tested both Hexakopters on different laptops and XBee pairs and obtain similar results.

We concluded that the new brushless controller was the main cause behind the XBee’s failure to connect after a flight.

 

Edit: Today I found out that the Hexakopter using the BL 1.0 had similar connection issues outside – totally making our previous work null and void.

Oct 22 2010

Weekly Flight Progress (Week of 10/17/10)

This past week I got in 3 good flights at UMBC and New Jersey and learned a lot more about how to get things working well.

The first flight was at the pine barrens site in Pemberton, NJ.  I arrived at the site on Saturday to scout things out.  I met the local forest researcher Ken Clark and he showed me around the plot where I would be flying and we checked out the forest from atop a modular tower used for making meteorological measurements; I was not crazy about climbing the tower, but Ken had no problem.  I was up at 6am Sunday and at the site by 7:30.  By about 8am I had inflated all of my new huge 3' diameter balloons and set out to place these new aerial markers in the field.  This ended up working pretty well, although I think I put a tiny hole in one balloon and several balloons popped between the time I set them up and when I went to retrieve them.  It was gusting to about 13mph (according to the local met data, thanks Ken!) and the balloons blew around and into the trees throughout the morning.  Overall the flight went well, but I think that because of the gusty winds, the Hexa got blown of course several times and we may have issues with image overlap during the 3D reconstruction. Site prep took about 3 hours as it was more challenging to place the balloons in the field than when I am just using buckets on the ground.

The next flights were both on Thursday at the UMBC Herbert Run location.  I had everything set up by about 11am and then commenced with flight testing.  I think it is a good idea to use a spare battery for testing out the flying conditions on site prior to the actual image collection mission.  I found that the GPS and altitude were holding well, but that it was still quite windy.  At this site I use buckets instead of balloons as they are more stable and there are more open areas to place the buckets.  Things went well on the first flight, but the Xbee inexplicably cut out quite often.  I thought it was odd that the Xbee cut out so frequently because there was almost no data connection problem at the New Jersey site earlier in the week.  Also, it was apparent from the Garmin Astro track that the route was being affected by the wind.  I landed the unit after the flight and swapped in a new lipo, new camera battery and new camera memory card and proceeded with another flight at an altitude 40m above the first flight and along the same route.  The track of this flight showed a similar pattern as the previous one.  I posted more about the flight paths and looking at the tracks in an earlier post this week, here.  In all I got in two full flights in under an hour, by myself, with about one hour site prep. 

 

In summary, I had three good flights this week that I setup and flew on my own.  It looks like at each flight winds above 13 mph may have caused the Hexa to deviate from the flight path, hopefully not to the detriment of image overlap.  I think the procedure for preparing gear and setting up the site is finally getting honed down to a smooth operation.  And thank goodness for my station wagon!