Henry Fletcher
  • Male
  • Oxford
  • United Kingdom

Henry Fletcher's Friends

  • Ozan Eren Yüceol
  • Yuan Gao
  • Anish
  • Doug Weibel

Henry Fletcher's Discussions

Overly Complex?

Started this discussion. Last reply by Chris Anderson May 18, 2010. 6 Replies

Hello all,I'm thinking of using the following for an autopilot:Arduino Mega connected to:9 Degrees of Freedom - Razor IMU - AHRS compatibleSerial Servo Controller -> connected to at least 3 micro…Continue


Henry Fletcher's Page

Profile Information

About Me:
Co-Founder Mavrx and Universal Air (UAir)
Cambridge University (UK) Engineering Graduate
Please tell us a bit about your UAV interest
General...been into RC aircraft for a while now, and want the ability to go out of visual contact ( even if I can't on account of legislature!)
Oxford UK

Henry Fletcher's Blog

Switching from DCM to Quaternion

Posted on January 6, 2012 at 9:24am 35 Comments

We've recently made the move from the old clunky DCM implementation to a new Quaternion approach, and it seems to perform better, or at least the code is much smaller and takes almost no time at all to execute on our 72MHz 32-bit flight controller. I'll be writing an article on the Quaternion method as part of our series on Engineering Insights.

We've also added MAVLink support, and full integration with QGroundControl GCS.  This helps greatly with debugging, and of course enables…


'Engineering Insights - Lesson 2: Testing and Tuning Always takes Ages!

Posted on December 27, 2011 at 8:00am 3 Comments

Video of ROFL Tuning Session with spectacular crash when we deliberately detune one of the PID values! No quadcopters harmed (much) in the making of this video.  Video of stable flight below.

By the way, the ROFL quadcopter kit is still on sale on my website:…


Engineering Insights - Lesson 1: Problems with Prototypes!

Posted on December 10, 2011 at 6:30pm 5 Comments

Seraphim is our sensor board for the quadcopter, it includes accelerometer, gyroscope, magnetometer, barometer, GPS and micro-SD card slot.  With the exception of the GPS unit, all of these components are a complete pain in the backside to solder properly, and there are some consequences of not…


UAir: Integrated Wireless Comms - Making life soo much easier!

Posted on September 11, 2011 at 3:03pm 3 Comments

Here you can see the little guy we have just begun to use and will be releasing for sale in early October. The black Forebrain board is what was running the autopilot code in ROFL up till now, 72MHz ARM Cortex-M3 microcontroller, measures 66mm*23mm.  The longer Hivebrain board is what we will switch to and will…


Comment Wall

  • No comments yet!

You need to be a member of DIY Drones to add comments!

Join DIY Drones


© 2018   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service