jma89

Member Since: November 26, 2010

Country: United States

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Spoken Languages

English

Programming Languages

HTML/CSS, PHP, MySQL, BASIC (For what it’s worth)

Universities

Davenport University

  • From what I’ve read it was actually due to a mistake/gerber file error in their first large batch of boards.

    See post 4 on this Arduino Forum thread

    Also reference from the Electronics StackExchange

  • Flexible filament also works well for printing designs on fabric that don’t necessarily require lots of height. Simon (from the RCLifeOn YouTube channel) did a few tests with 3D printing directly on t-shirts and had good success with flexible filaments.

    Here’s one of the videos where he shows everything after going through a couple different approaches: https://www.youtube.com/watch?v=YUW8G4vXZfg

  • There is an easy way to do programmatically simple “encryption” that’s uncrackable: A one-time pad, or OTP.

    Basic gist: Have a single-use random string that’s the same length as (or longer than) the message you wish to send. Take your original message, add the OTP to it (per-character), and then MOD 26 the result (again, per-character. The Wiki page has a great example section for this.)

    Only downside is that the security of a OTP comes from the secret never crossing an insecure channel. You could preload the entirety of spare flash with a massive (or several smaller) pads, then mark in EEPROM when they get used. (The base station would similarly keep track of this.)

    Once all the pads are used up you’d have to re-compile (with new pads) and flash your transmitter again. Bonus points for just using a “small” (~8 GB) SD card instead and filling it with pads. Even if you did use them all it’s just a matter of swapping in a freshly filled card.

  • They do support booting from the network without an SD card on some hardware: https://www.raspberrypi.org/blog/pi-3-booting-part-ii-ethernet-all-the-awesome/

  • With Shawn’s work on the Laugh-inator complete, Nick has to work furiously to add a Self-Destruct button before he passes out.

  • Ugh So much metric. I’ve converted units for those (like me) who can’t relate to metric measurements that easily:

    Fully fueled, it weighs [almost] [3.1 million pounds]. It will be capable of putting [142,000 pounds] into Low-Earth Orbit (for reference, the entire ISS weighs [about] [882,000 pounds]), [59,500 pounds] into Geosynchronous-Transfer Orbit, [37,500 pounds] into Mars-Transfer Orbit — or sending [7700 pounds] to Pluto (seven times the mass of the New Horizons spacecraft). It has a total of 27 first-stage engines generating over 5 million pounds of thrust at liftoff.

  • As cool as those outlets (and their supporting infrastructure) are, I do wonder what the ROI is on them, both from a monetary standpoint and an environmental standpoint. (All the extra support material has impact too.)

  • Could 3D print a case to hold the LEDs (and diffuse the light), and use said case as a sly way to slip a 90 degree USB OTG adapter in to talk with a cheap micro that could drive the LEDs.

    Only thing left to manage is auto-launching a full-screen app, and locking it down so folks don’t poke around and break stuff. (The commercial offering we use also supports finding another open room based on what building/location you are in, and also provides a mechanism to report a device or hardware failure in the room, such as a bad Ethernet drop, misbehaving TV, or dead remote batteries.)

  • We run one of the more commercial solutions, and one of the nice features these units have is a nice red or green rear illumination (to the wall): If there’s a meeting going on, it’s red, otherwise green. Wouldn’t be too crazy to make it go yellow ~10-15 minutes before the next meeting if you were to roll your own though.

  • This whole money-first attitude isn’t helped by organizations that are publicly held either: Suddenly you have thousands of other people who now own a (typically tiny) piece of your organization, and the only thing they are interested in is getting more money back.