Larry Grater
  • Male
  • Fort Worth, TX
  • United States
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Larry Grater's Groups

Larry Grater's Discussions

Auxilary TM Output Using UART2/Serial2

Started this discussion. Last reply by Dan Ho Feb 8, 2013. 15 Replies

I'll preface by saying that I'm not a C++ developer.  There are multiple references to APM2/2.5 support for UART2 on the forum.  Most references don't seem to come to conclusion.  I think we have…Continue

NMEA Lat/Long Parser Error for Arduplane 2.40 and Subsequent

Started this discussion. Last reply by Randy Aug 15, 2012. 1 Reply

If you are not using NMEA disregard.I recently discovered what I think is a parsing error for the NMEA lat/long decimal minutes in the latest version(s) of the GPS library.  I found this when doing…Continue

Compilation Issues with Arduino 022 or 023?

Started this discussion. Last reply by Larry Grater Feb 7, 2012. 1 Reply

I wanted to make a minor change to uncomment WITH_NMEA_MODE, run a GPS test in Mission Planner for Venus GPS (didn't get that far).  I got compiler warnings with both 2.27 and 2.28 using both 022 and…Continue

ArduIMU V2 + HMC5883L

Started Sep 30, 2011 0 Replies

I'm currently flying the ArduIMU with DragonOSD in an Eraser XE high performance glider.  This is working well and I realize that I don't need accurate yaw (using v. 1.6f). I am looking forward to…Continue

 

Larry Grater's Page

Latest Activity

Larry Grater commented on Andrew Rabbitt's blog post APM-guided High Altitude Glider Drop Simulation in X-plane
"Link Paul, I don't really want to hijack the thread too much but you might want to look at the link above.  I did end up using FG for my HIL simulations.  With new versions of the code the SIL route might be best since you get better…"
Mar 22
Larry Grater replied to Max Messinger's discussion Enabling and using analog inputs
"Max, I was hoping someone else would respond since I'm not sure I did things right.  But, it worked.  In v 2.65 I followed suit in sensors.pde, modeled after the way the voltage pins are handled.  Then I had to extend the…"
Mar 10
Larry Grater replied to Ralph Wu's discussion Sending APM to near space and return?
"My release was servo activated and the servo was inside the insulated airframe (as was my elevator servo).  The servo was controlled with APM based on altitude, longitude, freefall and time constraints.  Some of that is probably not…"
Jan 1
Larry Grater replied to Ralph Wu's discussion Sending APM to near space and return?
"North Texas Near Space 4 I had lost that link, thanks for posting.  It was interesting to review.   This was posted elsewhere, but thought you might like to see APM at altitude.  Minor SW issues have been corrected for a re-try…"
Jan 1
Carl La France left a comment for Larry Grater
"Hi Larry I finally got a chance to view your video of the 101k today I liked the release it dropped clean then spun down to the thicker air around 57k got control and started hunting for the way points. When I first seen it pull it's nose up…"
Dec 16, 2013
Dennis Okeefe left a comment for Larry Grater
"do you know what the max dynamic pressure you saw during your 101K flight?  do you have velocity vs altitude data that is available to look at? dennis "
Nov 23, 2013
Larry Grater commented on Chris Anderson's blog post APM-powered space plane has successful autonomous return from 100,000 ft
"Andrew,  I'm looking forward to 2.76 for the reasons you mentioned.  The current code writes a bunch of multi-rate data to an external SD card by way of UART2 and slows the fast loop to 38 Hz.  This is just barely enough but does…"
Nov 20, 2013
Larry Grater commented on Chris Anderson's blog post APM-powered space plane has successful autonomous return from 100,000 ft
"Thanks for the kind words guys.  Over the next few weeks I'll post my mods to the stock Arduplane code.  Actually the roll rate feedback issue that resulted in the initial dive is fixed in 2.76.  The vehicle wanders about after…"
Nov 19, 2013
Larry Grater replied to Andrew Tridgell's discussion APM:Plane 2.76 released
"Bravo to Andrew and the team on the DCM fix.   I'm positive that you've found the issue that eventually caused my 1st high alttiude return attempt (NTNS-2) to lose attitude reference (Link).  This flight experienced 2-3 Hz…"
Nov 5, 2013
Larry Grater replied to Monroe Lee King Jr.'s discussion Resources for model making in the group Model making for FlightGear and X-Plane (HIL)
"Monroe, I did the stinger manually. This is really similar to other aero models we used to do before the cad tools got involved with cfd mesh generation. Pretty easy. The aero data looks reasonable. The DATCOM preprocessor generates the geometry…"
Jun 27, 2013
Larry Grater replied to Monroe Lee King Jr.'s discussion Resources for model making in the group Model making for FlightGear and X-Plane (HIL)
"Andreas, instructions for simple model synthesis are on the on the FG website. I went as far as creating a DATCOM model of a Stinger 64 (my airframe) and creating a flight dynamics model. The FG geometry was auto-generated. Unfortunately the FD…"
Jun 27, 2013
Larry Grater replied to A. Fleyfel's discussion Setting up stabilise mode to damp rotation but not auto-level
"This is fairly easy, but you will have to do some modifications to software to accomplish what you want.  The standard controller doesn't actually use the rate process variable but uses a standard PID.  The guys can correct me if…"
Apr 18, 2013
Larry Grater replied to Ralph Wu's discussion Sending APM to near space and return?
"The video below link below is interesting because the RC Explorer guys talk about how hard this is and that it took 4 tries to get satisfactory results.  Well, they didn't even scratch the surface.  Here's a link to the post…"
Apr 15, 2013
Larry Grater replied to paul riseborough's discussion A batch of faulty Pitot/Static probes - how to detect and fix in the group ArduPlane User Group
"Great write-up; and complete with a fix!  I found that all 3 of my probes leaked somewhat.  This one thing that may have contributed to measuring only about 1/2 of the dynamic pressure on my North Texas Near Space 2 flight.  My fix…"
Apr 6, 2013
Larry Grater replied to Ralph Wu's discussion Sending APM to near space and return?
"Last weekend NTNS-3 hit its target LZ at 9k AGL from a drop at 48k.  Video to follow."
Mar 22, 2013
Larry Grater replied to Rick Stewart's discussion Connecting an APM 2.0 to other devices.
"Rick, Did you get this working using the GPIO pins or did you go a different direction?  My application (an ACS) would need 6 channels. Thanks, Larry D. Grater"
Mar 10, 2013

Profile Information

About Me:
Aerospace Engineer with 27 or so years experience in aerodynamics and flight control.
Please tell us a bit about your UAV interest
I've been in RC for years, interested in autonomous flight DIY.
Hometown:
DFW

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Larry Grater's Blog

NTNS-2 Flies to 88k ft with Stinger 64 Airframe (partial success)

Posted on August 24, 2012 at 4:00pm 23 Comments

On 5/18/12 North Texas Near Space (NTNS-2) achieved a maximum altitude of 87959 ft over a sparsely populated section of North Texas. The flight was…

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Stinger 64 HAB Early Integration Pictures with APM2

Posted on July 17, 2012 at 9:30pm 8 Comments

I've just finished the build and will begin early full up integration testing in the next day or so on NTNS-2.  This is a highly modified Stinger 64 with APM2.  There are really 2 airframes.  One is for flight testing, gain tuning, learning a little about APM2.  I have to admit that there have been several issues. …

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APM-1 Ride-Along HAB Flight to 86688 ft (Dual Launch, also from Albuquerque)

Posted on May 29, 2012 at 8:30pm 5 Comments

On 5/20/12 North Texas Near Space (NTNS) and Project Soar collaborated on a dual launch during the annular eclipse. Albuquerque was directly in path of the eclipse. The NTNS payload had most of the electronics that I had intended for a guided flight. That airframe is no more, but I have some data that I'd like to share with the group as a result. The dual launch was a great target of opportunity…

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Comment Wall (2 comments)

At 1:52pm on November 19, 2013, Dennis Okeefe said…

do you know what the max dynamic pressure you saw during your 101K flight?  do you have velocity vs altitude data that is available to look at?

dennis

At 2:49pm on December 15, 2013, Carl La France said…

Hi Larry I finally got a chance to view your video of the 101k today I liked the release it dropped clean then spun down to the thicker air around 57k got control and started hunting for the way points. When I first seen it pull it's nose up and the sun come into view I knew the flight would be a success the further  it descended the more solid it became right down the groove..It must have been quite a scramble to get from the launch to the landing area. you could poke around and maby get a grant to collect upper atmosphere air samples to look for various levels of ozone and such.Congradulations on the flight thanks for sharing it with me  I will study it again in detail and see if any thing extra ordinary stands out Have a good Day! Carl

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