slewis

At Google my colleague developed a simple test that made vibration effects very obvious (this was in 2008). In a server with a bunch of disks, do random reads or writes on all but one disk. On the final disk, do sequential reads. Back then you could get on the order of 100MB/s sequential read speed on the outer edge of a hard drive in ideal conditions. Under this test performance would dive to something like 10MB/s or worse. All of the seeking would cause vibration, which caused misreads on the disk under test. When a bad read happens a hard drive has to wait until the next rotation to try again. We eventually fixed this with better damping.

There were expensive bikes back then too. There are cheap bikes now. It depends where you look.

Who gets to decide which laws are ok to break? What do you think of medical marijuana users in the US (still 100% illegal at the federal level)?

Would you mind explaining the shift change in more detail? Did the employer hire more in order to lower everyone's hours below the overtime limit?

There are some very thoughtful comments in response to the parent, and I'm not degrading them. I just want to say in addition to an upvote that yours is more than just thoughtful. Thank you.

The article says over and over again it's a toy.

Young people, 14-25 are going to buy these and make them cool. Not the 35 year old engineers who bought Google Glass.

Google has never made something cool. Snapchat was cool out of the gate.

You just laid out YOUR version of a perfect company. There are, of course, plenty of people who disagree with you.

Yes, so if you have a uniform distribution of nodes and gateways over space, a node's nearest gateway gets closer as network density increases.

Shawn from Beep here. It's definitely an interesting area for us. We've created a tracker demo but don't have any information on our site about it yet.

I love the idea of inductively charging the dog tracker when the dog is in bed (though we're unlikely to pull that off anytime soon given the state of wireless charging).

You can do a lot with battery life if you only turn the GPS radio on when the user wants to locate the item. This type of product requires really good network coverage. We could make one last for 4-5 months on a single AAA battery.

If you want it to check in every 10 minutes with GPS data it would only last for 3.5 days. If you get smart with an accelerometer you can push that out to 1-4 weeks or more depending on how much the thing you're tracking moves around.

It's a fun product area with lots of parameters to tweak!

Ah you mean on the topo map, not the Google map at the top. Thanks.

Thanks!

You mean in 9 months? We're hoping to do one earlier than that :). Hit me up: shawn at beepnetworks dot com

It's a great point. A smart network needs to scale down the transmit power of its nodes and gateways as the network density increases.

LoRaWAN requires AES128: https://www.lora-alliance.org/portals/0/documents/whitepaper...

The radio chip itself doesn't perform the encryption though, it's done on the host microcontroller.

What kind of things are you monitoring?

I believe Microchip licensed the IP from Semtech and has made their own chips: http://www.microchip.com/design-centers/wireless-connectivit...

Shawn from Beep here. These use-cases sound really interesting. Send me an email? shawn at beepnetworks dot com

Yes -137dBm sensitivity: http://www.semtech.com/wireless-rf/rf-transceivers/sx1272/

In the blog post we were using 27dBm transmissions. At that level the radio and power amplifier draw about 1.5W. If a transmission takes .3seconds that's .5Watt-seconds. So with a single AA battery (about 5Wh) you can do 40000 transmissions.

Transmissions can be much shorter in time depending on radio parameters, by a factor of 32 at most, but range can be affected.

Shawn from Beep here. Are you referring to LoRaWAN networks specifically? I'm always down to talk wireless schemes. Hit me up (email in my profile).

We go beyond LoRaWAN with our own protocol for some use cases.

For those following along: LoRa is a wireless encoding technique (PHY layer), LoRaWAN is a protocol for how a large group of devices should structure their packets (MAC layer).

Shawn from Beep here. We use the 902-928MHz band in the US.

Try Redis: https://github.com/antirez/redis

Or Lua: https://github.com/LuaDist/lua

The DAC in the iPhone is as good as any external DAC you can buy, when it comes to human perceivable sound quality. Any other claims are audiophile BS and placebo.

There are valid product reasons for moving away from the 3.5mm jack though, like adding a power line that allows you to make active noise-canceling headphones that don't require their own battery, or outputting to more than two (stereo) speakers over a single cable.

There was one on Mission St in San Francisco until last year. Expensive but worked in a pinch for basics (through-hole capacitor kits for example).

Thanks. I'd poked through the howitworks. What threw me off was the reference to Etherpad, which made me think apps could somehow run on SandStorm unmodified. Makes sense now!

Can you explain the "Fine-grained Object Containers" concept a little more?

For example, how is this enforced: "JavaScript running in the user’s browser can talk only to the document container for which it was loaded, no others."

Do apps need to be SandStorm aware? Thanks!

Couldn't browsers keep a map of js-file-hash to cached AST?

You have the correct mental model, but does the next person who modifies your code?

That's not what I said. I took issue with tptacek's statement that there was only one bug.

Everyone is either saying go to a big corp or go to a startup as your first job.

What I usually tell new grads is: Get offers from both, and take the job that has the best potential person or people that you'll be able to learn from. There are a bunch of ways you can research this. Try asking people on the team to tell you who they've learned the most from in their career.

Do not take a job where you'll be a lone wolf. As a new grad your goal should be to find great people to work with and learn from them.

If you want to have a balanced career you should try both big corps and startups, but ordering doesn't matter.

Why wouldn't it be considered a bug that accessing one low-permission S3 bucket allowed him to access all the other buckets, including user data and keys?

Counter argument. Usability does not have to be number one. There are lots of programming languages out there. What if one had a unique take on a website? It's healthy for people to try new takes on things.

I laud the approach. I think it looks cool and on first glance makes me think, "wow, this doesn't look like it was made by engineers who only think practically, maybe I'll go further to see if there are some unique ideas in the language itself".

In other words, don't speak like there is only one true way to do things, especially when you're critiquing someone else's work. (this last statement is slightly in jest as I'm doing the same to you!)

I haven't seen anything using MIMO yet. Not sure how that would affect power usage. The closest thing now is that a key aspect of Ingenu's solution is receive diversity. All of their client radios require two antennas.