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jma89
Member Since: November 26, 2010
Country: United States
Profile
Spoken Languages
English
Programming Languages
HTML/CSS, PHP, MySQL, BASIC (For what it's worth)
Universities
Davenport University
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The ElectroDroid app on Android has a lot of calculators, LED resistor values being one of them. (Can't speak to the equivalent for iOS devices though.)
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Which peak is that in the background of your over-lake shot? (And would you happen to have a higher-resolution version of said picture?)
Re: GPS projects: I still have it on my (ever growing) list to create a simple heading-distance indicator to the nearest edge of a box bounded by three or more GPS points. I plan to use it for marking my property edges so we can create trails and such without inadvertently crossing onto the neighbor's land. I figure an RTK-enabled receiver ought to be plenty accurate for that sort of application. :-P
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You could also just flash the lights (or maybe one and then the other) to indicate a pending shutdown. I've seen several office lighting systems that do this and then wait 1 minute before shutting the lights off for the night. Anybody can then meander over and tap the light switch to cancel the shutoff.
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I'm not sure if this is the case, but it almost looks like there are a few isolated ground planes around the power supply region.
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ElectroBOOM just did a video on Ohm's law as well, and described the relationship between current, amps, coulombs, voltage, and resistance very well:
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The schematic is available on the GitHub page:
https://github.com/PiSupply/PiJuice/raw/master/Documentation/PiJuice_Schematic.PDF
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What technological improvement spurred on by AVC has impressed/inspired you the most? (Both in the maker community and commercially.)
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From what I've read it was actually due to a mistake/gerber file error in their first large batch of boards.
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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
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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.
