Hackaday Links: September 3, 2017

The TI-83, TI-84, and TI-86 have been the standard graphing calculators in classrooms for two decades. This is the subject of an xkcd. Now, hopefully, there’s a contender for the throne. Numworks is a graphing calculator that looks like it was designed in at least 2006 (so very modern), and apparently, there’s a huge community behind it.

Juicero is shutting down. No one could have seen this one coming. The Juicero was a $700 press that turned proprietary, DRM’ed juice packs into juice and garbage. It was exquisitely engineered, but it turns out very few people want to spend thousands of dollars per year on DRM’ed juice. Oh, since the Juicero phones home, those $700 presses probably won’t work in the future.

Are you in the Bay area? Do you need test equipment? There’s a gigantic auction happening somewhere around San Jose. [Dave] tipped everyone off to this one, and this auction is pretty freakin’ spectacular. Spectrum analyzers, signal gens, a ‘mega zoom’ oscilloscope, and 4-channel, 500 MHz scopes for $50. There are a thousand lots in this auction. It’s nuts.

Everybody loves PCB art, and [Uri] has a guide for designing custom, functional electronic circuit boards. The toolchain used in this guide is Inkscape and KiCad, with blinky hearts, blinky pandas, and other blinky PCBs.

This one is a little out there even for us. Here’s how you build your own AA batteries. It’s a dozen #10 copper washers, a dozen or so #10 zinc washers, some cardboard, vinegar, salt, and some heat shrink tubing. The assembly of this battery is exactly what you would expect, and yes, it does work. Here’s the thing, though: The very crude tests suggest these batteries have a capacity of about 800-1000 mAh, which is far more than we would expect. Who has a programmable load and wants to do a few experiments? Also, these batteries are ‘rechargeable’ by taking them apart, sanding the crud off each washer, and adding new electrolyte.

[Jan] has made a name for himself stuffing synthesizers into tiny little microcontrollers. The latest project is the Infinity37, a polyphonic synth with MIDI, envelopes, and a whole bunch of cool stuff. Check out the video.

[rctestflight] is building a solar powered aircraft. It’s has a beautiful wing studded with solar panels. The latest flight was four hours, long enough to make piloting a plane through some FatSharks extremely tedious. Future developments will probably include a MPPT charging solution, and probably an autopilot.

35 thoughts on “Hackaday Links: September 3, 2017

    1. “What Numworks seems to be missing is RPN entry”

      Yup, from what I can see from a cursory look at the product, there’s no RPN support. This is an epic FAIL in my opinion. If you REALLY learn how to use a handheld instant-on RPN calculator device, everything else is just a Toy in comparison.

  1. I would question the value of any dedicated calculator in an era of pocket sized supercomputers (smart phones) with a plethora of free maths learning tools available for them. You can get far more for $99 if spent on a phone and I do get the bit about the calculator being used for exams, even then the security of that approach is questionable if you can bring your own, potentially hacked, calculator rather than have one assigned to you in the exam room.

      1. This is exactly why TI-89s are great. Simple, old school, no funny business. They do what they’re supposed to do without a bunch of distracting extras and they have a long battery life.

      2. Stating your level of ignorance is not proof that your claim is relevant or correct. You could shoehorn an ESP8266 into a lot of calculators if you were as skilled as many of the people featured on this site. Would you even notice if a TI-89 or whatever was 2 or 3 mm thicker than spec?

        Did you deliberately ignore “bring your own, potentially hacked, calculator ” and are trolling, or are you simply an idiot? Honestly I can’t tell.

        1. Do you really think every grade school kid is going to “shoehorn” anything into a calculator? And then hook it up to power? And then hook it up to the school wi-fi? And then hope to find the exact answer to the test question? Wouldn’t it just be way easier to study? And they already aren’t studying… Honestly, if they make these Numworks as open as possible, lots would be able to spot a cheater a mile away.

          1. Their phone outside the room or wherever is the AP for the ESP8266 and yes, all it takes is one kid to do it and then they would sell the mods to all their friends, as per the distribution for all other cheating methods that can be duplicated in some way. You’d be surprised what some rich but stupid kids will pay to avoid failure. It is only a matter of time before calculators will need to be supplied per exam session to ensure they don’t contain a hack. Welcome to the 21st century.

          2. In high school kids offered to pay me once to program equation solvers into their calculators before a test. I said no because I’m not a cheater, but it occured to me I could have made a LOT of money.

        2. Wow, rude. Did you deliberately ignore that there’s an actual person writing these comments and are trolling, or are you this mean in person too? Honestly I can’t tell.

          I think you could tell if a TI-89 was 2 or 3 mm too thick because the cover wouldn’t fit (at least, it would be tight as all get out). And as asperw says, how many high school kids would be able to do that, really? We’re the exceptions on this site, mind you.

        1. Dan, calling other people ignorant or idiots is not proof your claim is relevant or correct, nor does it make you look smart. Arguments will need to back your claim up, not bravado or spite. Be nice.

    1. I have 2 dedicated calculators because while smartphone calculators are better than nothing if I have to do complex maths ‘out in the wild’, if I’m sat at my desk and trying to work out something, I’d much rather have tactile keys and be able to focus purely on the calculator properly. Even computer calculator apps don’t come close to the workflow of a good calculator at that time.

      (The 2 calcs are a casio and a TI-84+, the TI-84+ is nice for many things, but it’s big, bulky (a lot of this is the 4*AAA), and lacks a reasonable base-n mode, the casio is dual-power (solar+button cell), thin/light and has a nice base-n mode)

      1. This. I have tried multiple calculators on my smartphone, but I far prefer a real one. Especially when I was doing exams – in fact, I preferred my basic scientific calculator except when the graphics calculator was actually needed.

    1. I feel if I was designing a calculator I’d use something like the NH10WM/NH14WM form-factor battery, there’s plenty of 3rd party support (especially since some vaping companies piled on it) and it’s something that you can ‘just use’

  2. I suspect many of these exams where you can use a calculator explicitly list the approved calculators by name and aren’t likely to list this new one (when I was in school, they had a very specific list of approved calculators including some TI models, some Casio models like the one my school had standardized on and I think some HP models)

    1. Equipnet handled the aution of gear from broadcom Oulu unit here and tons of people bought stuff from it. Some for fairly decent prices.
      If you want good prices you need to buy something older and more obscure.
      GSM testers went for under 50eur while LTE capable devices went for 5000-50000eur for example.

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