Tuesday, December 20, 2016

Popcorn

I really like popcorn.  I often find myself watching TV just as an excuse to eat popcorn.  I've gone months where I had it every night.  A while ago I decided to buy an air popper.  I've built up quite a recipe around the air popper, and I'd like to outline it here.

Why an air popper?
Air poppers are like $20 and the popcorn is much cheaper than the microwave bags.  They are a bit faster than a microwave, and you can never burn it.  There is nothing to clean because you only put dry popcorn in them, the oil is added afterwards.

Air Popper
I did a fair bit of research into air poppers, as I tend to do before buying anything.  Long story short, they're all the same, and you should get a cheap one.  This one is about $20.  It has a built in measuring cup, you dump the dry kernels in the top, and plug it in.  Set a large bowl next to it, and wait a few minutes.  The last 10 or so kernels never pop, so give up on them.  Unplug and that's it.

Kernels
A few people recommended Orville Redenbacher for air poppers.  I started out buying at the grocery store, but you can get a giant jug on Amazon for cheap

Bowl
It sounds silly, but you do need a large bowl.  I always ate popcorn straight from the bag, so I didn't have one.  I just got a 7 L one from Walmart.  Make sure it's at least 6 liters.

Salt
You can just use regular salt, but finer salt will stick better.  Generally you'll waste tons of salt no matter what.  After much research I found this movie theater style salt which is great, and will last like 30 or so bowls.

Salt Shaker
You can just use any regular shaker.  But I'm generally looking for one that has a few, well-separated, smaller holes.  The popcorn salt is much finer, so it comes out very fast of normal sized holes.  This is the best I've found so far, it works, but the holes could be a bit smaller.

Oil
You need oil, basically to make the salt stick.  I've just been buying this generic popcorn oil.  Don't expect much flavor from the oil, it's basically just soybean oil.  I've heard coconut oil is the best flavor, but it's difficult to spray on.

Sprayer
It's basically impossible to drizzle oil evenly.  I bought this spray bottle, which is crazy expensive, but is designed for oil.  There are cheaper oil sprayers but the reviews say they clogged, whereas I've been using this one for months and it's fine.  A word of warning, they spray in a flat fan pattern, which means you have to move the sprayer as you spray.


Saturday, October 1, 2016

Body Cameras Are Betraying Their Promise

http://www.theatlantic.com/technology/archive/2016/09/body-cameras-are-just-making-police-departments-more-powerful/502421/
In case after case, police departments say officers did not have their body cameras activated when it counted. It can seem as though incidents where body-cam footage helped secure an indictment—such as in Marksville, Louisiana, last November, or as in Cincinnati last July—are more rare than the cases where they don’t.

These are breaches of protocol—incidents where events didn’t happen as the law would require. Often, these violations are never significantly punished. This is the second major threat to body-camera accountability: If there’s not significant discipline for officers who fail to follow local policies—as the officers failed in D.C., Chicago, and Charlotte—then it doesn’t matter what’s in the policy.

Will Raccoons Trump Rats as the Ultimate Urban Mammal?

http://www.slate.com/articles/health_and_science/science/2016/09/raccoons_are_taking_over_urban_environments.html
And I heard from a friend who works in the State Department about a raccoon that snuck into her building while it was under construction, and then walked across ceiling tiles until it got to her office and hung out above her desk, visible through the mesh-type ceiling panels, perhaps attracted by the scent of her sandwich.

Saturday, September 3, 2016

Replacing a modded Xbox with a Raspberry Pi, as a classic game emulation station

As you're likely aware, I'm a big fan of using orginal Xboxes modded to allow playing various NES and SNES (and sometimes N64) games.  Xboxes are cheap, and the software that runs on them has a pretty good UX.  That being said, they are getting pretty long in the tooth, and while the finished product is pretty slick, the process of modding them is annoying enough that I pretty much refuse to actually do it.  They are also rather huge and unwieldy in the age of tiny single board computers that are more powerful and draw far less power.

I have a few Pi 3s so I'd figured I give RetroPie a shot.  This will be less of a how to, and more of a review/comparison to modded Xboxes.


What you need

This is probably the biggest draw back of the Pi vs Xbox.  An Xbox can be had for $40 pretty reliably, or probably free from somewhere.  They generally come with everything you need to play, including at least one controller.

The Pi costs $40 by itself.  You then need a power adapter, a HDMI cable, a case, and an SD card.  Then you'll need controllers, 2 SNES knock offs will cost $30, or you can use XBOX360 ones if you want wireless and joysticks, but that'll bump the cost up $70 more.


Name Cost Link
Pi 3 $36 https://smile.amazon.com/dp/B01CD5VC92/
Power $10 https://smile.amazon.com/dp/B00MARDJZ4/
Case $8 https://smile.amazon.com/dp/B01F1PSFY6/
SD Card $10 https://smile.amazon.com/dp/B010Q57T02/
2 Controllers $25 https://smile.amazon.com/dp/B002B9XB0E/
HDMI $6 https://smile.amazon.com/dp/B014I8SSD0/



Total $95

You might have some of this stuff, but I don't think it's fair to assume you do for the price calculations.  So the cost is at least double an Xbox, probably more if you want joysticks.


Install

I won't give a full install guide here, you can follow the official guide easily enough.  However, I will say the install is far easier than an Xbox.  Download the image, write it to the SD card, pop the card in the Pi, attach controllers, and power it on.  It autodetects the controllers, and lets you configure them.  FTP in (u: pi, p: raspberry) and put roms in the ~/RetroPie/roms/* folders.  Restart and the systems where it finds roms will show up in the list.


Config

There isn't much to config, you can pretty much just play out of the box, however, there were some things I wanted to change.  For example, I found the layout of NES buttons to be annoying.  A bit of research told me that while the initial global controller set up is easy, there is no way to edit per system controls without editing the cfg files.  For NES the file is at /opt/retropie/configs/nes/retroarch.cfg

You can SSH into the Pi with ssh pi@192.168.1.125 (change the IP to yours), then cd to there, and use nano to edit that file.  Alternatively, you can FTP the file back and forth. The config is very confusing due to the fact that you have the labels on the controller and in the file which may not match.  The numbers refer to the position of the physical button on your controller.  The letters refer to what that button should do.  For the Buffalo SNES knock offs this was my config for NES:

input_player1_b_btn = 3
input_player1_a_btn = 1
input_player1_y_btn = 2
input_player1_x_btn = 0


Thoughts

I think it works pretty well.  There are some rough edges, but I guess those are mainly a concern for someone like me that wants to configure everything.  All the games I tested work well.  The one exception was N64, where they stuttered quite a bit.  The Xbox was never great at N64 either, but it feels like it did better than the Pi.  Perhaps that's just the few random games I tested, or maybe because the Pi doesn't actually have a video card.

Also there is no easy way to turn the Pi on and off, you just unplug it.  For what it's worth, I measured the Pi as using about 2 watts (compared to the Xbox at about 50 w), so leaving it turned on 24/7 isn't a bad idea.

I was kind of disappointed at how poor N64 performance was.  If that were better I'd spend the money for a set of wireless controllers and be quite happy.  Each release of the Pi see a pretty significant speed bump, but at the same time I don't know if that is going to actually help, I think it's more the software and lack of video card.

Wednesday, August 31, 2016

Saturday, June 18, 2016

Flash the BIOS

Prelude

Some years ago-never mind how long precisely-having little money in my purse, and nothing particular to interest me on shore, I thought I would set about to fix a friend's computer.  I can't recall what was actually wrong with it, but at some point, I figured I might try to flash the BIOS for no real reason.  The long story short is I used the wrong BIOS file and ruined the computer.

Since then "Flashing the BIOS" has become an inside joke.  That being said, I've learned a lot of lessons over the years, and would not make the same mistakes today.  As an example, let me regale you with this tale:

A New Router


I recently moved, and my best internet option here was xfinitywifi which is broadcast in the area.  However, I needed to be able to connect any device to that without going through their web portal, and be able to hook up wired devices.  Simple enough, I bought a router, and installed DD-WRT on it.  There was the potential for bricking the router, but I did my research and found a version of DD-WRT with numerous confirmed successful installs on the internet.

The install went fine, and as an added bonus, the antennas on my router picked up the xfinitywifi signal much better than my laptop.

Premonitions


All was well in the world.  But then my internet started going down.  It turns out my router would lock up and crash, and need to be restarted.  This seemed to be happening with increasing frequency.  The solution seemed obvious.  I bought a 120 V relay and wired it to a Raspberry Pi.  I then wrote some code to ping some sites to see if the internet was still up, and if not, to restart the router.  This was an iterative process, as I discovered the router would sometimes allow pings to IPs (like google's DNS 8.8.8.8), even in its frozen state.  I also noted that pings to the router would occasionally still work, even when the router refused to serve the status page.  So I changed the script to check the status page via wget.

This worked pretty well.  I set it up to run every 30 seconds, and to restart the router as soon as it couldn't get the status page.

Discontentment


Searching online though, it seemed like no one else was having this problem.  I figured this may just be because I was using the less common repeater mode, but it may have also been because I was using an older release of DD-WRT, since I wanted to find one with plenty of confirmation it wouldn't brick the router.  I found one or two people who said they were running the latest version on that router so I decided to upgrade the firmware to the newest version.

I carefully found the correct file, and plugged directly into the network so there was no chance of being disconnected during the update.  When I figured I was ready, I hit upgrade.  As soon as I clicked the button I realized my mistake.  My router was still hooked up to my crazy Raspberry Pi contraption.  Within the next 30 seconds the Pi would try to get the router status page, fail, and then cut the power to the router.

There was nothing I could do.  Pulling the plug on the Pi would cut the power to the relay and cause it to open.  My only chance was to SSH into the Pi and kill the process.  That, of course, relied on the network being up.  As soon I hit enter on the SSH command I heard the click of the relay turning off.

And with that, my router was bricked.

I tried a few recovery methods I found online, but it didn't matter.  My router had a half installed firmware, there was no way for it to boot, so it looped endlessly.

Excursion


While connecting directly to xfinitywifi gave me some internet, it was unreliable and I wanted to get this resolved.  I convinced myself just to get a new router, one that would hopefully not have the freezing problem.  Walmart was the only place that was open so I found that they carried the Netgear Nighthawk router and set off to buy it.  I arrived at 12:01 am to discover that the Walmart I was at closed at midnight.  I drove to another Walmart to discover they didn't have any in stock (despite their site claiming they did).  I bought a lesser router, figuring it might be better than nothing.

A New Hope


When I got home I thought more about what to do with the broken router.  I, of course, considered switching out the guts, but I didn't have any of the packaging, and knew I couldn't just put the old router in a new box since the serials wouldn't match.

I did more research and discovered two more advanced recovery methods.   The first involved setting up a TFTP server, and connecting directly to the router, with a static IP that it would check for a certain file and then flash itself with.  I set this all up, and as luck would have it, it got the file from my computer and started to flash itself.  Then it rebooted, and rebooted.  I guess it didn't have enough firmware written to get through the firmware update steps before it rebooted.

A New Hope, Part 2


The more involved method, as these things so often do, required opening the router and soldering some pins onto the board.  While my new apartment is pretty barren, one thing it does not have a dearth of is random electrical components.  I had pin headers, male to female jumpers, even a USB to UART breakout board.  It was about 3 am at this point, which seemed like the ideal time to begin the next phase of this project.

I opened the router, found the through-holes, broke off three headers and placed them in the correct holes.  Hooked up Rx, Tx, and Ground to my UART, plugged that into my laptop, and attempted to connect via PuTTY, and got nothing.  It was pretty odd as I was sure the connections were right.  I have done USB serial communication stuff before though, and I know it's very easy to get the connection details wrong.  That being said, usually that would result in gibberish, not nothing.  After much experimentation I noted I could sometimes get gibberish if I moved the connections around.  This led me to believe perhaps the connections actually needed to be soldered, and not just placed there.

At this point, I feel it's worth noting that while I have a nice large table in my living room, I only get internet via my laptop in my bedroom.  I did buy a large corner desk for my room, but have yet to assemble yet, despite sitting around in my apartment every day with nothing to do.  As such, all this work was being done with me in bed with the parts in bed with me.


Dawn


It was about 4am when I turned on the soldering iron (which I did do in the living room, not in bed).  I soldered the headers on, and as is tradition, discovered I soldered it wrong, so had to unsolder everything and redo it.  I hooked everything up, and still got nothing.  I suspected my router had so little firmware on it, that it couldn't even communicate over serial.  I checked and rechecked the connections, but there were only 3 wires.  Ground to ground, Rx to Rx, and Tx to Tx.  Then I realized, how could Rx connect to Rx?  Both sides can't be receiving.  Sure enough, the directions I was following clearly stated Rx to Tx.  At 4:45 am I fliped the Tx and Rx wires and immediately got communication.  As I said, I've done this USB serial communication before, and I made this same exact mistake before.

Flashing the firmware was a few simple commands, it grabbed the file from my TFTP server, via ethernet, and rebooted.  It worked fine.  I figured I might as well reflash it with the DD-WRT firmware while it was in this disassembled state.  That was done in a few minutes, and the router was reassembled (with pin header conveniently left soldered on for future endeavors) by about 5:15 am.  Just in time to watch the sun rise while browsing reddit.

Monday, May 23, 2016

Monday, May 16, 2016

Dean Karnazes: the man who can run for ever

http://www.theguardian.com/lifeandstyle/the-running-blog/2013/aug/30/dean-karnazes-man-run-forever
When running, you break down glucose for energy, producing lactate as a byproduct and an additional source of fuel that can also be converted back into energy. However, when you exceed your lactate threshold, your body is no longer able to convert the lactate as rapidly as it is being produced, leading to a buildup of acidity in the muscles. It is your body's way of telling you when to stop – but Karnazes never receives such signals.

"To be honest, what eventually happens is that I get sleepy. I've run through three nights without sleep and the third night of sleepless running was a bit psychotic. I actually experienced bouts of 'sleep running', where I was falling asleep while in motion, and I just willed myself to keep going."

Monday, April 4, 2016

Will minimum wage hikes lead to a huge boost in automation? Only if we're lucky.

http://www.vox.com/2016/4/2/11348148/minimum-wage-robots
What about the workers thrown out of jobs by the new robo-waiters? Many would get new jobs, though the way this would work is often ignored.
  • Most restaurants would keep longer hours (they're paying for the rent and the robots anyway), meaning many workers would get a raise and change shifts.
  • The advanced robo-restaurant technology would itself be a valuable American export good, and people would be employed in designing and selling it.
  • Some low-wage work would be reallocated out of the relatively low-social-value restaurant sector and into things like child care and home health assistance, for which there is ample demand.
  • Since poor people are now making more money, there will be opportunities to sell them things — things like restaurant meals! — that they couldn't previously afford, which in turn creates demand for new jobs.

Thursday, March 31, 2016

I'm Speechless


Tuesday, March 15, 2016

Primitive Technology

This guy's videos are quite mesmerizing, and his descriptions are quite interesting to read.

Making Charcoal

Building a tiled roof hut

Sling

Sunday, March 6, 2016

When U.S. air force discovered the flaw of averages

https://www.thestar.com/news/insight/2016/01/16/when-us-air-force-discovered-the-flaw-of-averages.html
He decided to find out. Using the size data he had gathered from 4,063 pilots, Daniels calculated the average of the 10 physical dimensions believed to be most relevant for design, including height, chest circumference and sleeve length. These formed the dimensions of the “average pilot,” which Daniels generously defined as someone whose measurements were within the middle 30 per cent of the range of values for each dimension. So, for example, even though the precise average height from the data was five foot nine, he defined the height of the “average pilot” as ranging from five-seven to five-11. Next, Daniels compared each individual pilot, one by one, to the average pilot. 
Before he crunched his numbers, the consensus among his fellow air force researchers was that the vast majority of pilots would be within the average range on most dimensions. After all, these pilots had already been pre-selected because they appeared to be average sized. (If you were, say, six foot seven, you would never have been recruited in the first place.) The scientists also expected that a sizable number of pilots would be within the average range on all 10 dimensions. But even Daniels was stunned when he tabulated the actual number.

Zero.

Thursday, February 25, 2016

Sunday, February 21, 2016

The Secret Wizard of the Far Right

http://www.gq.com/story/rex-elsass-secret-wizard-of-the-far-right
While you've likely never heard of him, chances are good you know his clients. Name a conservative firebrand and Elsass has likely been on his or her payroll. Ted Cruz, Rand Paul, Michele Bachmann, Newt Gingrich—he's worked with all of them, as well as a slew of Republican agitators who aren't yet household names but are doing everything in their power to change that. Elsass now counts more than 60 members of Congress on his client roster, many of whom belong to the rebellious Freedom Caucus that last fall hounded the Speaker of the House, John Boehner, into early retirement. This year, while most eyes are fixed on the presidential race, he's quietly obsessing over the Republicans' control of Congress, guiding the fortunes of 15 first-time candidates whom he hopes will join his small army already wreaking havoc in Washington.

Not surprisingly, Elsass's electoral success has made for a lucrative business, as the fleet of late-model Mercedes sitting outside his firm's headquarters attests. During the 2014 elections, the Strategy Group grossed more than $150 million—a figure that would be stunning even if the firm was located in the Beltway and not out among the mega-churches and big-box stores of exurban Columbus.

Tuesday, February 16, 2016

Kids, forget console gaming—play the FBI’s browser-based game instead

http://arstechnica.com/tech-policy/2016/02/kids-forget-console-gaming-play-the-fbis-browser-based-game-instead/
It basically looks like a prequel to the world's first-ever video game. The player uses the left- and right-arrow computer keys to move a running goat to avoid blocks. The blocks apparently represent violent extremists. Hit the block, and the goat explodes.

Saturday, February 6, 2016

Saturday, January 30, 2016

Why did crime plummet in the US?

http://www.vox.com/cards/crime-rate-drop/crime-rate

I thought this was a very good compilation of the various proposed reasons for the huge drop in crime in the 90s, and some debate for and against each.

Friday, January 29, 2016

Listen to Wikipedia

http://listen.hatnote.com/
Listen to the sound of Wikipedia's recent changes feed. Bells indicate additions and string plucks indicate subtractions. Pitch changes according to the size of the edit; the larger the edit, the deeper the note. Green circles show edits from unregistered contributors, and purple circles mark edits performed by automated bots. You may see announcements for new users as they join the site, punctuated by a string swell.

Sunday, January 10, 2016

Powerball Odds

So there is a lot of Powerball talk, and I am again intrigued by the possibility of a positive expected value for a lottery.  If you remember I wrote a post about Megamillions a few years ago, when the jackpot grew to $640 million.  The result, after taking into account both taxes and multiple winners, was that it still wasn't worth playing.  I decided to quickly do the same thing for this latest Powerball jackpot.

In a separate post, I made a model to predict the ticket sales based on jackpot amount.  This was quite a bit of work, so I'm not doing that here.  I'm just going to use the data for the latest drawing (Jan 9th, 2016) to see if that one drawing had a positive expected value in retrospect.

To begin, the expected value of the non jackpot prizes is $0.32, or about $0.28 if you include tax on the $50,000 and $1,000,000 prizes.  Note here, I'm ignoring the "Power Play" thing, which increases the payout for the nonjackpot prizes, but costs an extra $1.

Now we need to look at the jackpot.  The estimated upfront payout was $587,662,740.  After taxes that's $340,844,389.  The odds for Powerball recently got way harder, which is why this jackpot is so large.  This drawing had 440,321,172 tickets sold.  Doing the Poisson distribution we see the probability of various numbers of winners based on the odds and tickets sold:

0 22.1594%
1 33.3922%
2 25.1595%
3 12.6377%
4 4.7610%
5 1.4349%
6 0.3604%
7 0.0776%
8 0.0146%
9 0.0024%
10 0.0004%
11 0.0001%
12 0.0000%
13 0.0000%
14 0.0000%
15 0.0000%

The odds for no winners (which is what happened) was 22%.  This is due to the much lower odds of a jackpot in general.

Adding up the adjusted jackpot shares gives a total of $176,335,787.  This could be thought of as the true jackpot value after adjusting for taxes and the possibility of splitting the jackpot.  Multiplying by the odds of winning gives an expected value for the jackpot of $0.6035.  Adding the nonjackpot expected value gives a total Powerball expected value of $0.88.  The ticket costs $2, so it's not even half the value.

Some thoughts:  The odds were just increased in Oct 2015, and this is the first huge jackpot after that change.  More will follow, so it is possible that the expected value will improve as people get over the hype of a billion dollar jackpot.  However, it is worth noting that even if the jackpot doubled, and ticket sales remained constant the expected value would still be below the ticket price.


I haven't gone into details for the math here.  The calculations and commentaries are the same as the Megamillions post.  So please see that for more discussion.