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Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"In the blog post on the Convergence, I measured 168Hz for the FrSky converter.
That was independent of the value for parameter SERIAL_SBUS_RATE, which defaults to 50Hz.
If you have an oscilloscope or logic analyzer you should check what you're actua…"
Apr 11, 2018
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"That looks good, too. Beware that some sbus to pwm converters will output frame rates > 50Hz, which might be a problem with analog servos. If you're using ESCs or digital servos, that's OK."
Apr 10, 2018
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"Glad you like it. I just noticed that there's now a very tiny single channel converter from FrSky: https://alofthobbies.com/frsky-sd1-sbus-converter.html
Of course, without the pins and wrapper, the 4 channel one is also pretty small."
Apr 10, 2018
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"you could use Sbus and a PWM converter as described here: https://discuss.ardupilot.org/t/e-flite-convergence-with-pixracer-a...

Sbus supports up to 16 channels, and there are both 4 and 8 channel sbus to PWM converters on the market. So using one…"
Apr 9, 2018
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"The PixRacer does not have an analog input pin dedicated to airspeed input. I use the MS4525 and MS5525 digital sensors on I2C instead. Juan C Ricardo said:
Hi guys:

Anyone knows here if I can wire an analog speed sensor to pixracer ?
regards and…"
Dec 10, 2017
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
Dec 10, 2017
Mark Whitehorn replied to Mohammed A. Shakir's discussion HELP! analyse the reason behind crash
"If we rule out the power supply as the cause, that would indicate a random component failure on the Pixhawk.
Since you aren't using any non-3DR components, there would seem to be no other possible causes."
May 25, 2017
Mark Whitehorn replied to Mohammed A. Shakir's discussion HELP! analyse the reason behind crash
"My guess is that the safety coprocessor, or a related component has failed. I'd replace the Pixhawk and make sure that its power supply is reliable, since there's a chance the failure was caused by a spike on the power input. Are you using the servo…"
May 25, 2017
Mark Whitehorn replied to Mohammed A. Shakir's discussion HELP! analyse the reason behind crash
"Have you tried booting with the safety switch pressed?"
May 24, 2017
Mark Whitehorn replied to Mohammed A. Shakir's discussion HELP! analyse the reason behind crash
"That 72 second interval has no log entries; between log index 1527975 and 1527976, TimeUS jumps from 2070 seconds to 2141 seconds.  Andre K. said:
Like Graham already pointed out, there is no yaw tuning, and if you rolled plane enough, using rudder…"
May 22, 2017
Mark Whitehorn replied to William Premerlani's discussion Centrifugal compensation with only gyros and accelerometers
"Hi Bill, 
I finally got around to playing with this concept in multicopters, and it's looking very encouraging for estimating airspeed. Here's a plot from a quadcopter flight log where I flew circles in a "coordinated" way, and also with constant he…"
Jul 5, 2016
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"The RC input of Pixracer is 5V tolerant."
Jun 22, 2016
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"That is correct. The Pixracer's servo rail does not connect to its internal 3V3 regulator. That is powered only via the power module input and the USB port.
A "star" ground configuration will keep motor currents out of the ground connection for the…"
May 27, 2016
Mark Whitehorn replied to Randy's discussion PixRacer with Ardupilot
"nice job. Looks like a good candidate for 3D printing too."
May 25, 2016
Mark Whitehorn replied to William Premerlani's discussion Centrifugal compensation with only gyros and accelerometers
"Bill, I thought you might be interested in this paper which I turned up while refreshing my memory on coordinated turns: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810013509.pdf
73, Mark"
Jun 23, 2015
Mark Whitehorn replied to William Premerlani's discussion Centrifugal compensation with only gyros and accelerometers
"Hi Joe,
You definitely have more full-scale experience than I, all of my solo time was in a Cessna 150 :)
But I'm not sure what you mean by "you can place a multicopter in a turn and perform 360 yaw spins with no adverse effects".
Certainly a multic…"
Jun 23, 2015
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