Wikipedia:Reference desk/Archives/Computing/2016 February 14

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February 14

Wireless webcam for Skype?

I've tried to find a true wireless webcam on www.amazon.com and could not see one. I would like to walk around the house having this webcam on my forehead like a headlamp and talk into a built-in microphone hoping that the images and the sound will be input into the Skype application in my desktop. Is it possible? Thanks, --AboutFace 22 (talk) 02:06, 14 February 2016 (UTC)

Pretty much all smartphones could do this directly without needing a desktop, if you can improvise a head mounting. If you want a separate camera, I think most Go Pro style cameras could do this as well. There's probably a cheaper non-branded alternative to those. Fgf10 (talk) 02:48, 14 February 2016 (UTC)

How do I set up automatic buying on eBay?

I am not sure where to post this, so I settled on the Computer Help Desk, here. I was reading a Wikipedia article (Auction sniping). In the article, way at the bottom under the "Buy It Now" section, it states: Many of these buyers use custom software to search eBay frequently via eBay's API and RSS feeds in order to see newly listed BIN items before "regular" users have a chance on the standard eBay.com website. These users are actively waiting for new items to be posted and make quick purchasing decisions as these deals usually sell within the first minutes or even seconds. What the heck does that mean, exactly? I am not that familiar with computers and technology, which is why I probably don't understand what it's saying. I also have no idea what all those acronyms mean (API, RSS, etc.). Please advise. In other words, if I want to do this (i.e., find these items before the "regular" users have a chance to), what exactly is it that I need to do? Thanks. Joseph A. Spadaro (talk) 06:13, 14 February 2016 (UTC)

@Joseph A. Spadaro: Become a computer nerd. Nerds rule the world. Basically these people are using software to check for recently added ads.

eBay's API allows someone who writes a computer program to make the program interact with eBay (see Application programming interface).

An RSS feed is a list of stuff, in this case a list of items on eBay.

There is loads of software like this, both paid and free (if you Google "ebay sniper" you will find stuff like jbidwatcher), but it is better to write it yourself.

It is, for example, possible to write software that asks eBay every five seconds: "Do you have an advertisement that mentions the word uranium?".

When eBay API answers that there is an advertisement that contains the word uranium you can make the software warn you (e.g. by sending an email), or you can even make the software buy it without requiring any human input.

Of course this is a silly example, but you get the idea.

If you really want to do this then the first step is to learn a programming language (or to convince a nerd to help you). Most of the people who are doing this kinda stuff professionally have their own custommade software, and they aren't sharing it for obvious reasons. The Quixotic Potato (talk) 06:40, 14 February 2016 (UTC)

Thanks. I am still unclear, but it's starting to make a little bit of sense. So, assuming that I do not use the "automatic purchasing method", doesn't that mean that I would have to be on constant vigil, watching the computer (or my email or whatever), waiting for these "warning" messages? I would have to be staring at my email inbox 24/7, no? Joseph A. Spadaro (talk) 06:58, 14 February 2016 (UTC)

@Joseph A. Spadaro: Nope. Most smartphones have the ability to regularly check your inbox, and warn you whenever you have a new message. You can use a browser plugin (like Checker Plus for Gmail) that warns you whenever you receive an email. It can check your inbox every 30 seconds and you can configure it to shout: "You've got mail!". And of course using email isn't required, it would also be possible to write software that sends a text message every time an eBay ad for uranium appears (but it is 2016 and no one uses text messages anymore). The Quixotic Potato (talk) 08:03, 14 February 2016 (UTC)

Screenshot. The Quixotic Potato (talk) 08:16, 14 February 2016 (UTC)

That's my point. I have to be on constant vigil with my email or text messages or whatever warning system I have. Whether I get a "you've got mail" prompt or not, I have to always be keeping vigil with my emails and texts. Right? Joseph A. Spadaro (talk) 08:19, 14 February 2016 (UTC)

@Joseph A. Spadaro: Well, to me keeping vigil sounds like you actually have to pay a lot of attention (non native speaker here, please correct me if I am wrong). Many people have an smartphone on them 24/7, and you can configure the smartphone to start buzzing or ringing when you receive an incoming text message. And many people spent most of their time within earshot of a computer with speakers attached, and you can configure the computer to start making sounds when you receive an email. So you don't have to sit somewhere staring at your inbox 24/7, you can just live your life normally, and when the phone rings/buzzes or the computer starts making noise then you'll know that you can buy more uranium (purely for non-nefarious reasons of course). The Quixotic Potato (talk) 08:25, 14 February 2016 (UTC)

Yes, I see. But, your assumptions are inaccurate. I have a computer, but I don't sit at my PC 24/7, obviously. I have a cell phone, but I don't carry it with me 24/7. It might sit on my desk, while I go on about my day. I am not "attached at the hip" with my cell phone and/or computer. So, if I wanted to make sure that I hear these beeps and buzzes and messages, etc., I'd have to keep a vigil on my computer and/or cell phone. Which I would otherwise not do. In other words, me and my cell phone (or me and my PC) could be "separated" for hours at a time (or even days at a time). I know this is not the norm with the younger generation. But, it's quite the norm for us "older" folks. And I am not even that "old". Joseph A. Spadaro (talk) 09:07, 14 February 2016 (UTC)

@Joseph A. Spadaro: If you do not sit at a PC 24/7 then you must be very very old. The question "how to relay a message to someone who is walking around outside and doesn't have a mobile phone/laptop with him/her?" is difficult to answer. Walkie-talkies are basically mobile phones, that's too easy. You can use messenger pigeons for fixed locations or maybe a robot (or well-trained dog, or child) or something like that for when you are on the move. Personally I would recommend using something similar to the Bat-Signal, but I don't think that'll work in bright daylight. Maybe you can use a smoke signal during the day. But if you don't bring a smartphone/tablet or computer with you when you go outside then it is probably pointless to relay a message to you that requires the use of one of these devices to act on it. The Quixotic Potato (talk) 09:33, 14 February 2016 (UTC)

OK, thanks. Joseph A. Spadaro (talk) 10:17, 14 February 2016 (UTC)

Not sure if this would work, but if you are interested in specific items that there isn't a huge demand for, you might still get them before they are posted if you check your e-mail once/twice a day. It would depend on how many other people are using software to search for those items, and how long the delay is between your software finding the item, and it actually being posted. Another option would be to have the software make the purchase for you (similar to algorithmic trading, with all the attendant methods and pitfalls). OldTimeNESter (talk) 13:05, 14 February 2016 (UTC)

Of course none of the people who use this kind of software are able to use a computer/smartphone 100% of the time, which means that they may miss out on certain deals while they are sleeping (for example), but in some cases auction sniping can be lucrative, even if you do it for only a couple of hours per day. The Quixotic Potato (talk) 16:49, 14 February 2016 (UTC)

Note that the option to have the computer buy things for you automatically that match a certain criteria is a very dangerous one:

1) You have to limit the numbers, or you could find you bought a thousand items overnight.

2) You would have to pay attention to total cost, as sometimes an item is listed for $0.01, with all the profit coming from the high shipping costs.

3) It would be difficult to buy the precise item you want. For example, you tell it to buy any "TV sized 42 inches or greater, for sale for under $100", and you may find it selects old analog TVs, as well as remote controls, stands, mounts, and instruction manuals for such TVs. So, you could end up spending lots of money and not actually getting a TV you can use.

4) Another program might figure out what your program is doing, and tailor the descriptions of whatever they are selling to match the description you are looking for: "Pet rock for sale that's great to play with while watching your 42 inch TV". :-) StuRat (talk) 17:20, 14 February 2016 (UTC)

You certainly have to be very alert for those things - when a new game console comes out and is in short supply, you'll see a rash of people offering to sell the box that the game console came in for roughly the price of the game console itself. It's inconceivable that someone would spend several hundred dollars on an empty box - so it's clear that these people are trying to catch out the unwary buyer...and an automatic, software-based buyer would be about as unwary as you could possibly imagine! SteveBaker (talk) 16:53, 15 February 2016 (UTC)

Pets and toddlers often show more interest in the box than the toy that came in it, so they must be the ones bidding. :-) StuRat (talk) 17:28, 15 February 2016 (UTC)

Not just boxes, but also pictures. However eBay has not taken too kindly to listings which appear to be intend to mislead in the past, even if a careful reading shows the truth [1] [2] [3]. Obviously people may really want to buy boxes and I guess rocks, so there's no clear line. Still even if title says rock (or box or photo), it would probably be smart to at least contact the buyer and make sure they realise what they are getting. If you try to sell your rock for $200 BIN and put it in the TV category (or whatever), I wouldn't give you good chances if the buyer complains regardless of how many times you specified rock in the title or listing. Also, unless you're super effective at sending your rock, the buyer may check and complain before you've sent the item, in which case I suspect you'll have even less chance of surviving a complaint. There are still risks with completely automatic buying, for more subtle problems (intentional or not) perhaps including faulty items and also real working items which aren't supposed to be what your program is buying. But given all I've heard about eBay I don't think it's that extreme. However if you do keep accidentally buying items then complaining or asking for your purchase to be cancelled because you didn't misread the description, it possible eBay will suspend or cancel your account. Nil Einne (talk) 20:38, 15 February 2016 (UTC)

Thanks, all. Joseph A. Spadaro (talk) 21:12, 18 February 2016 (UTC)

Google apps and passwords

The Google system from my point of view consists of platforms (my phone and computer) and their applications which I use (gmail, Google+, Chrome,etc.). Google requires passwords for some of these (gmail) but not those in the public domain, like Chrome.

I have a password on my PC which gives me access to everything Google there. However, I find out, on my phone and any other devices I need a different password.

So I follow the process to get one. I am at the screen on my phone where they want a username and password. I have no password, but I notice that "Need Help" is displayed. I click through the screens to the end. There, they say: "[If you} are trying to sign in to your Google account through a device, mobile app or desktop app, you'll need to enter an app password."

I follow the link which explains in detail what passwords are all about and so on, but it doesn't tell me what I need to know: How do I get a password for this device?

The page helpfully tells me I should go to a certain web site, enter my username and password and type the letters on the screen. Then I am to go back to the application and enter my app password.

There is no contact information given.I would try to contact Google, but I believe that information does not exist anywhere.

I"m serious. This is what happened.

Can you help?

Sorry, I meant to let you know who I am. --Halcatalyst (talk) 20:14, 14 February 2016 (UTC)

@Halcatalyst: An App password is a 16-digit passcode that gives an app or device permission to access your Google Account. If you use 2-Step-Verification and are seeing a “password incorrect” error when trying to access your Google Account, an App password may solve the problem. Most of the time, you’ll only have to enter an App password once per app or device, so don’t worry about memorizing it. Visit your App passwords page. You may be asked to sign in to your Google Account. At the bottom, click Select app and choose the app you’re using. Click Select device and choose the device you’re using. Select Generate. Follow the instructions to enter the App password (the 16 character code in the yellow bar) on your device. Select Done. The Quixotic Potato (talk) 22:08, 14 February 2016 (UTC)

I know. I saw all that information on my phone. You didn't leave anything out; if fact I believe what you wrote is exactly what I saw on my phone. But I still don't know to get out of the endless loop I described above. --Halcatalyst (talk) 23:39, 14 February 2016 (UTC)

Where is the process failing? Can you get to the App Passwords page? What happens when you enter your username and password? Tevildo (talk) 16:49, 15 February 2016 (UTC)

Just to clarify, the password you need on the App Passwords page is the password you use to access your Gmail account, not the app password (which hasn't been generated yet). Tevildo (talk) 18:25, 15 February 2016 (UTC)

Battery behaviour/usage Log software

Any idea where I could find a good software that logs the battery usage/dealings physically? --Apostle (talk) 21:06, 14 February 2016 (UTC)

@Russell.mo: BatteryMon (screenshot) & BatteryInfoView The Quixotic Potato (talk) 22:28, 14 February 2016 (UTC)

The Quixotic Potato: Hello, is there a software that displays the full battery charging/discharging history? Since day one...? -- Apostle (talk) 18:36, 15 February 2016 (UTC)

Maybe. I don't work for the company that manufactured the battery. Maybe they have software like that. But I doubt that they'll give it to their customers. The Quixotic Potato (talk) 22:48, 15 February 2016 (UTC)

Thank you, that will be easy for me to follow up on.

I understand. Thank you -- Apostle (talk) 18:50, 16 February 2016 (UTC)

@Russell.mo: SteveBaker wrote: "the battery microcontroller is logging your charging and discharging behavior". That may be true, depending which battery it is, but it is wrong to assume that this data is accessible to customers. There is no universal piece of software to display this information because there isn't one universal way to store this information, it depends on the manufacturer. So some of the manufacturers probably have software that can read the battery log, but you cannot afaik. The Quixotic Potato (talk) 20:25, 16 February 2016 (UTC)

Noted! -- Apostle (talk) 05:26, 17 February 2016 (UTC)

How to assess the CAPEX of U-TUBE heat exchanger?

Dear sirs, my name is Saade Haddad, Manager of Zouk power plant in Lebanon. we intend to purchase 3 U-TUBE heat exchangers. I shall be very grateful If you could provide me with a practical procedure that would allow to assess the CAPEX of each heat exchanger, or inform me about references that can help us for this purpose.

Regards

Saade Haddad — Preceding unsigned comment added by 178.135.82.98 (talk) 21:11, 14 February 2016 (UTC)

I assume that by CAPEX you mean "capital expenditure"? If so, I'm afraid we can't give financial advice on the Reference Desks. If, however, you're referring to a performance characteristic of a heat exchanger, we may be able to help, but you'll need to clarify what you mean. Tevildo (talk) 22:36, 14 February 2016 (UTC)