Hackaday Links: September 18, 2016

No Star Trek until May, 2017, at which time you’ll have to pay $5/month to watch it with ads. In the meantime, this is phenomenal and was shut down by Paramount and CBS last year ostensibly because Star Trek: Discovery will be based around the same events.

Tempest in a teacup. That’s how you cleverly introduce the world’s smallest MAME cabinet. This project on Adafruit features a Pi Zero, a 96×64 pixel color OLED display, a few buttons, a tiny joystick, and a frame made out of protoboard. It’s tiny — the height of this cabinet just under two wavelengths of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. Being based on the Pi Zero, it’s a capable arcade cabinet, although we would struggle to find a continuous rotation pot small enough to play Tempest the way it should be played. Check out the video.

[Graham] sent an interesting observation in on the tip line. It’s an election year in the US, and that can mean only one thing. It’s coroplast season. Coroplast is that strange material used for political signage, famous for its light weight, being waterproof, and reasonably strong, depending on how you bend it. There is a severe lack of coroplast builds, but if you have some be sure to send them in.

The ESP32, the followup to the hugely popular ESP8266 , is shipping. [Elliot] got his hands on one and found it to be a very promising chip, but the ESP3212 modules I bought from Seeed haven’t arrived yet. That hasn’t stopped [Ptwdd] from making a breakout board for the ESP3212, though. We don’t know if it works, but it’s just a breakout board, anyway.

The usual arguments for drones involve remote sensing, inspection, and generally flying around for a very long time. Quadcopters don’t do this, but fixed wings can. Over on DIYDrones, [moglos] just flew 425km on a single charge. The airframe is a 3 meter Vigilant C1 V tail, using the stock 300kV motor. The battery is a bunch of Panasonic 18650 cells arranged in 6S 9P configuration for 30600mAh. The all-up weight is 5.7kg. This is significant, and we’re seeing the first glimmer of useful tasks like pipeline monitoring, search and rescue, and mapping being done with drones. It is, however, less than half the range a C172 can fly, but batteries are always getting better. Gas goes further because it gets lighter as you fly.

25 thoughts on “Hackaday Links: September 18, 2016

  1. Could someone explain the “300kV motor” stuff? Every time I look up RC tech I roll my eyes at the stats; it’s a foreign language to me.

    The mini/micro/nano MAME cabinet is really cool! :D

    1. Kv is a motor constant. Specifically the velocity constant. (Kt is the torque constant).
      It is expressed as rpm/volt. E.g. a 300Kv motor with a 6S Lithium battery pack (nominally 22.2V) will give you an unloaded RPM of 6660

      Kv not kV (which is kiloVolt)

  2. I’ve seen some mention that DSC is supposed to air on Crackle in addition to CBS all access here in the USA but info on that is a bit scarce…. regardless I’m not inclined to pay $60-120 a year just for Star Trek Discovery. Not that I wouldn’t pay… but I’d rather not pay that much.

      1. If I am going to pay to see ads, I’m going to look elsewhere. It’s stuff like this that contributes to piracy. No one wants to see ads on paid content and it’s bad enough I have to spend 20 minutes of unskippable BD content to watch the actual movie that I paid $20.

        1. You are right I hear in the US you have two ad breaks in a 1/2 hour period here in the UK we have one every 1/2 hour on TV. I really think that ad to content ratio is crazy and I could never imagine watching tv with that many. Paid Tv should be banned from running ads during content before and after not so bad but I hate it when a show breaks off at the good parts for an ad.

          1. It is very frequent, or something pops up at the bottom of the screen. Two per half-hour seems like an understatement, though I’ve never kept track.
            At least certain on-demand channels you can fast-forward through some ads. It almost always goes into a LOUD advertisement for something (i h8 gìeço) during the suspenseful parts, or they cut out during an important conversation. I usually tend the dishes or flop laundry when the ads start; I’m not going to drink soda or change my insurance because a commercial interupted a good show.

  3. “cells arranged in 6S 9P configuration for 30600mAh” Is not a very useful metric — it doesn’t state how much energy is actually stored, since it doesn’t state the voltage. Much more informative to say it’s a 22.2V, 30.6 Ah (680 Wh) pack.

    And “Gas goes further because it gets lighter as you fly.” Yeah, sure, just like the rocket equation. But not relevant here. You’re skipping over the much more important fact that gasoline has more than SIXTY times the energy density of a battery. After the engine efficiency, you can go 20x farther on gasoline than on the same mass of lithium-ion batteries. The 680 Wh contained in that huge lithium pack would require just a coffee cup full (0.2 kg) of gasoline to go the same distance. Liquid fuels still rule for this application.

  4. Periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom were used to define the second, as you may know it is a unit of time, not weight.

  5. I was unaware that batteries are always getting better.

    Over the last twenty years advances have appeared insignificant.

    Cost has fallen as production investments have been recouped, so that’s good.

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