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1  Community / Bar Sport / Re: The perfect arduino murder! on: April 14, 2014, 12:06:49 am
Similar plot in the movie "Shooter", except they went a step further and blamed it on someone else.

You want to take all suspicions away when you shoot someone, wait till he's standing next to the President.
2  Using Arduino / Project Guidance / Re: Alarm panel communication options on: April 12, 2014, 08:29:27 pm
For a school I would think it would have to be differential RS485 (CAN BUS or MOD BUS)
CANBUS is 1000 meters (3280 feet @ 50kbit/sec  
MODBUS about 1200m for speeds less than 100kbit/s,17118.0.html  

Here's a tutorial example for RS-485  


The  120 ohm resistor is called a Termination resistor. There needs to be one of these at the two extreme ends of the bus.
The 470 ohm resistors are biasing resistors to keep the signal centered in the 0 to 5V range
RS485 will not work without the termination resistors to prevent reflected wave.

The alarm panels are fairly dumb devices. They just need to transmit 7 digit codes when they are armed/disarmed, and receive 10 character names when a zone is faulted. I think anything over 1kbit/s would be sufficient.

EDIT: you added some more since I originally read the post.

The termination resistors for r485 were what were worrying me, since this use case wont match that model. There will be many  (say, up to 5) devices that all connect back to a central point over varying distances. I was thinking that some type of rs485 hub would work.
3  Using Arduino / Project Guidance / Alarm panel communication options on: April 12, 2014, 07:41:15 pm
I'm attempting to rebuild a security system for a school department, and i'm stuck trying to find the best way for the main controller to communicate with the alarm panels (the panels with keypads and LCDs that are used to arm/disarm the system) that will be by each entrance. I will be replacing everything except the sensors (which are simple NC devices that open when tripped). I'm thinking the rs485  protocol may be the best, but i'm still looking for options. I'd like to reuse the existing wiring if possible. The existing wiring is 4 wires in a twisted pair format. On the old controller they are labeled +, -, RX, and TX, so I assume they are using some form of serial.

The primary concern is range. For the first installation there is only one remote alarm panel and its only 5 feet away from the main controller. For the other installations, the panels may be as far away as 600'. Does anyone know what method these alarm systems usually use to communicate over these distances? I imagine the manufacturer must use something that works in a wide variety of distances.

I also plan to use a Rasberry Pi running Apache as the main controller, so anything that can interface with the Pi directly would be great. If not, it would not be a problem if I have to put an arduino in the middle to facilitate communication.
4  Community / Bar Sport / Re: Lighting up my fume extractor on: April 07, 2014, 06:52:40 pm
Yes the resistors are on the strip and they are connected one resistor for 3 LEDs' so you can power it from a lower supply if you like.
Yes, you cut where the +  -   marks are so that you get the grouping right.

I use mine as a strip light over my work bench.

Tom........ smiley

I use these over my bench as well. The 300+ point sources of light are fantastic for taking pictures. My webcam picture now looks like i'm using professional studio lighting.

They also make nice battery powered emergency lighting.
5  Community / Bar Sport / Re: Things to be missed 10 years from now... on: April 02, 2014, 04:05:28 pm
So why do they not put them on aircraft

Government Logic: "Because they are for ships"
6  Using Arduino / Project Guidance / Re: long range wireless link to arduino on: March 26, 2014, 01:37:22 pm
Powerline ethernet is one option, but you may have issues with the range and noise generated by the pump. Ubiquiti wireless radios could probably make it. Put a 2.4ghz Nanostation Loco M2 on each side. Theres no way to judge a NLOS link without testing it.
7  Community / Bar Sport / Re: [HELP] Helping a friend winning a contest on: March 24, 2014, 11:38:00 pm
How advanced is the robot head? Does the head have enough intelligence not to spam random forums with Facebook competitions?

This could just be an SEO bot, the link should probably be removed by a moderator.
8  Community / Bar Sport / Re: Any method to restore win vista backup files (not system image) to win 8.1? on: March 24, 2014, 12:41:19 am
Thanks. I'm also thinking 120GB min. I will have a slimmed down OS or even dual win/Linux. My win 8 laptop with SSHD boots up in just a few seconds, fast enough. What the SSHD people argue about 8GB is that most boot files and apps won't take up 8GB. I hope their "research" is right. My new laptop has no mSATA slot. It's a dell inspiron 14r. My older laptop is a core-2-due so it's 5 years old. Definitely no mSATA. I'll see what SATA it takes.

Do you know if the SATA drives are backward compatible?

SATA drives are backwards compatible. A SATA3 drive will work in a SATA2 port, just slower. mSATA became a standard in 2009, so its possible theres a slot in there. mSATA is entirely different from SATA, its usually in a small 1" x 2" bay somewhere on the bottom of the laptop.

I'm not really a fan of SSHDs, the performance benefit is not worth the price. The SSD portion doesn't really store any files, its just used as a temporary cache. My Lenovo did come configured with some sort of Intel "RapidDrive" software that did what you are thinking though. It watched for the programs and files that I used regularly, and moved them to the 60GB SSD, replacing the originals with symbolic links.

Windows 8 boot times are mostly great due to the fact that it almost never turns your computer all the way off. Even the "shutdown" option just puts it to sleep.
9  Community / Bar Sport / Re: Any method to restore win vista backup files (not system image) to win 8.1? on: March 23, 2014, 08:54:21 pm
I only have laptops so no way to benefit from having two physical drives and upgrading to SSD+HDD. I have an SSHD with 8GB NAND flash and 1TB spinning hard disk. Hope it becomes fast after a week of usage.

How big SSD did you get and how do you like it? I'm now with an older laptop. I'm thinking about getting an SSD for it but need some advice.

SSD prices just fell through the floor, so now is the time to buy:

I have a 120gb SSD and a 60gb SSD in my gaming desktop, along with a 7500 rpm 500GB drive. I have a 60GB SSD and a 750gb HDD in my laptop. I'm thinking about swapping the 120gb in my gaming desktop for that 250GB that I linked you do, and putting the 120gb in my laptop.

What model laptop do you have? Most of them have a space mSATA slot that you can stick an SSD in. Mine has two mSATA slots, along with a standard 2.5" SATA bay.

I recently had to switch back to using the 750GB HDD as my boot drive on my laptop. The amount of suffering that the switch caused is not something that I can describe over the internet. Putting an SSD in your computer is the single largest performance boost that you will see.

I wouldn't go with anything lower than a 120GB SSD. You can get away with a 60GB sometimes, but Windows likes to make random 10GB files that drain your available space rapidly.

There is also a company now that is making a real hybrid SSHDD. It is a 120gb SSD and a 1TB HDD in a 2.5" formfactor. You install the OS to the 120GB SSD, then install a driver that makes the HDD available.
10  Community / Bar Sport / Re: Any method to restore win vista backup files (not system image) to win 8.1? on: March 23, 2014, 04:55:11 pm
This is why I have always used separate drives for files and for the OS. I can do whatever I want to the OS drive, format it, replace it with Linux, whatever, and my files remain accessible and untouched on the second drive. It also made the transition to SSD much easier, since my OS drive was never very large to begin with.
11  Community / Bar Sport / Re: Any method to restore win vista backup files (not system image) to win 8.1? on: March 23, 2014, 11:59:55 am
Have a look at Todo backup a free and (for me) a better product than Arcronis true image.

I don't think a disk imager will work, since he's going from Vista to 8.1. He needs something that only copies files.
12  Community / Bar Sport / Re: Any method to restore win vista backup files (not system image) to win 8.1? on: March 23, 2014, 03:33:50 am
Don't worry, I didn't wipe my vista machine. I can turn it on and painstakingly copying all folders to an external drive.

On the other hand, I have a complete file backup on my external drive. From what I read on msft forum, the win 7 file backup restore tool has been removed in win 8.1. I have 8.1, so I can't find a way to restore my vista files to my new machine. Mind you I have near 1 million files. I won't be opening each zip file and try to unzip and or stitch files.

Are these all just regular user files? Not installed programs?

The free version of Crashplan would probably work. You install it on both machines, have the old machine back up to the new machine, then once its done you go onto the new machine and do a local restore.

If your USB drive is faster than your network, you could have crashplan back the files up to your USB drive instead and move them that way.
13  Community / Bar Sport / Re: Marketing? on: March 23, 2014, 03:28:33 am
Seems I usually end up throwing out the TV before I have to change the battery in the remote control.

Seems like there's something wrong right there. How long does a TV set last these days before it gets thrown out?

2 - 4 years, unfortunately.
14  Community / Bar Sport / Re: Somebody please explain this incredibly interesting eBay scam to me. on: March 22, 2014, 07:23:39 pm

I'm going with money launderer.

I've always wondered how much money laundering and criminal activity happens on ebay. I sell a lot of random things, like small PCBs from old TVs. Occasionally i'll see a item that several sellers are failing to sell for $5 with free shipping, yet theres one or two auctions that went for $5,000+, with good feedback.

It'd be a good way to hide illegal sales, since you would have to look up a 10+ digit part number to even figure out what the sale was for, and most of these parts are so obscure it would be difficult to confirm that it wasn't a legitimate sale. A laptop selling for $15,000 would be easy to flag on a ledger, a $15,000 50PC3D ZSUS Board 6871QZH044C? Not so much.
15  Using Arduino / Project Guidance / Re: 4X3 keypad access code sketch on: March 21, 2014, 11:26:27 am
When I try to upload the above code, It gives me the following errors:

keypad:2: error: stray '#' in program
keypad:5: error: variable or field 'keypadEvent' declared void
keypad:5: error: 'KeypadEvent' was not declared in this scope
keypad:2: error: expected unqualified-id before '/' token
keypad:23: error: 'Keypad' does not name a type
keypad.ino: In function 'void setup()':
keypad:31: error: 'keypad' was not declared in this scope
keypad:31: error: 'keypadEvent' was not declared in this scope
keypad.ino: In function 'void loop()':
keypad:36: error: 'keypad' was not declared in this scope
keypad.ino: At global scope:
keypad:40: error: variable or field 'keypadEvent' declared void
keypad:40: error: 'KeypadEvent' was not declared in this scope

Is this a typo, or is it actually like this in your code?
/#include <Password.h>
Because there should not be a '/' there.
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