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Cheap yet relative accurate signal sensors

Thanks for visiting the nuthouse!
Anyhow, I'm trying to figure out a relatively cheap, yet accurate, distance-sensative sensor.

So, the end question is, does anyone know of a sensor type that can be mounted on an arm,
that moves from 0 degrees to 180, 6 inches apart, to detect my location by something I'm carrying?

-From what I've read, the standard RFID chips don't usually even cover 5 feet.
-I've tried bluetooth, but the sensor strength fluctuates too much for a clear reading,

A particular sensor

Hello. So I reread the rules and am going to pose my dillema as specifically as I can. I've been researching it for a couple weeks and am still stumped, so please bear with me...I'm just a beginner.


Here is the problem I am trying to solve, posed metaphorically.

What sensor exists, that would allow you to detect a particular tennis ball being dropped into a bucket, only that tennis ball, and no others? What would I have to attach to the bucket AND that one tennis ball that could detect and alert me it just passed into the bucket?

Read RFID tags from the Parallax RFID reader on the Raspi
How to connect the Parallax RFID Serial Reader to the Raspberry Pi safely. Using a Logic Level Converter from SparkFun to step down the 5V serial from the reader … Read more

RFID antenna

So I have this OMNIKEY 5534 MultiTag Reader, and according to the manual a test-antenna can be made with a coil of 70 turns with a 0.22mm magnet wire around 36mm spool.
That works great, but I need the spool to be 80mm in diameter, -so the question is, how many turns should I use with a MW30 (0.25mm) wire?


Hello LMR! This is sort-of a Two in one question. I need some assistance figuring how to hook up and program the following: 1. RFID - I've been eying this for a while now: http://www.sparkfun.com/products/8419. I understand that pin 5 will tell you when a card is present, and 8 & 9 look like i2c, but what is pin 7 (format selector)? What sort of object (propeller) would I use to drive it, i2c? What about the cp pin? 2. RTC - I've also wanted to do some experiments with this cool little chip: http://www.sparkfun.com/products/10160.
Read RFID tags and Smart Cards with this handheld device
A Basic Stamp 2px powered handheld device that can read RFID tags and Smart Cards then displays the data on an LCD screen. Future upgrades will include the ability … Read more

RFID Keylock - RBBB Propeller

Continued......... Video explains the details ....including the painstaking job of finding the right house wires....ekkk

Removed the "Elfish PC" as its needed on another project.........

..... Replaced with a super cool RBBB Propeller board M44D40 found on the parallax forum, for 20 dollars.

I choose this board because of its size and simplicity (it has to fit inside my RFID box) .

Serial RFID reader troubles

I recently purchased the seeedstudio serial RFID reader for 125khz tags, but I cant really understand the datasheet. I am having trouble figuring out how I am supposed to interface it with my picaxe. 

Here is the product:


And her is the datasheet:


Who wants to buy an RFID IC that is actually well made?

Oi all it's Tgeahre, your friendly neighborhood RFID Proponent.

I have good news, I found my RFID reading IC and want help getting it. To start, if you didn't read it before, take a look at my component report in node 1417. For those of you excited about RFID, this report will please you.

At the end I have a wonderful little bit about how to purchase it.

Price: $4.5 USD
There are a few models of this but the SM125-IC is an RFID Interigator with read/write capabilities and I2C connection capabilities. I have been looking for a chip … Read more

Has anyone worked with RFID


While I am waiting for my Picaxe28x1 to arive I have been looking at a few ideas that I want to play with. one of which is a device that regularly pings RFID tags to see if they are within the given area and warns the user if they aren't. basically this is used by a forgetful person like a friend of mine in long beach who leaves his swords everywhere when he drinks (which is pretty much always). I know that this whould be easilly done but I cant find any tutorials online dealing with RFID tags besides the ones telling buisness owners how to upgrade their invintory managment.