Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror

Comment: Re:Seriously? (Score 0) 110

"I am a fixed-wing pilot, anything that can fly through my window at 140MPH pisses me off. Birds are bad enough, but at least they're not metal."

  How often do you fly in uncontrolled airspace at less than 800' agl without major focus on your field of travel? Because if something "flies through your window at 140mph" in uncontrolled airspace, I would have to blame that on pilot error. And, surely that something could not be a DJI Quadcopter because their flight control systems won't allow function in ANY airports controlled airspace (much less approach path). In addition, within a 5 mile ring they limit altitude to 500" agl http://www.dji.com/fly-safe/ca....

Comment: What they really want. Just annother Clipper... (Score 1) 241

by fred911 (#49644749) Attached to: James Comey: the Man Who Wants To Outlaw Encryption

" They only want backdoorsâ"to break encryption, but just for the good guys."

And

"âoeThe FBI makes this proposal to look like theyâ(TM)re looking for a simple law to add a simple feature,â says Robert Graham, CEO at Errata Security. âoeBut when you look into it, what theyâ(TM)re really asking for is dramatic, itâ(TM)s a huge thing. Theyâ(TM)d need to outlaw certain kinds of code. Possessing crypto code would become illegal.â

  But that boat has sailed, just ask Zimmerman.

Comment: Why are they asking the exchange to halt trading? (Score 1) 185

by fred911 (#49581313) Attached to: How One Tweet Wiped $8bn Off Twitter's Value

When listed securities are traded with one specialist who has the ability to halt trading in order to match buyers and sellers and maintain an orderly market. Specialists don't have to ask to stop the market, they halt it until they can figure out what the market is pricing it at (keeping it orderly and making the spread).

Comment: CAN vs SPI (Score 1) 20

by fred911 (#49498023) Attached to: John Hawley Talks About UAV Controls (Video)

A significant part of the video is dedicated to an opinion that using UARTS for peripheral communication is best. The reasoning for this contention is:

#1 It's been around forever
#2 It uses plain text to transfer information
#3 Everyone understands it
#4 It's been around forever

  Correct me if I'm wrong, but a SPI generally only defines the transmission of a byte, whereas CAN defines the packets. Isn't another disadvantage of using a serial bus in this type of application the fact that basically we're looking at a "master/slave" relationship?

  If I want to drop in a telemetry stream to my video down-link, isn't it significantly more effective to use CAN? With the vast amount of peripheral devices, servos, video, barometers, magnetometers, GPS and who knows what else (not necessarily needed for flight control), why is it better to use the controller for handling communication timing and then figuring out how to talk, when CAN does it so effectively?

  I'm seriously soliciting more in-depth reasoning for preferring a SPI (using a UART) than what's been mentioned on the video.

Never buy what you do not want because it is cheap; it will be dear to you. -- Thomas Jefferson

Working...