This is a great piece of code and hookup diagram for the ID-20 and ID-12. The reader is great, one known issue is that the serial line (D0, pin 9) needs to be disconnected from Arduino RX in order to upload a new sketch to the board or else the upload will fail.
Reader has a range of about 8cm using the ID cards sparkfun sells. The thicker plastic key fobs are reading at about 6cm. With a case on this it should still have a great read range.
If you tie the Reset line to 5v+ as the datasheet says you will have to wait a maybe a second after moving the card out of range to read the same card again. If you connect the Reset line to a digital pin on an arduino you can bring the pin HIGH, read the card, then bring it LOW after a successful read. Looping this will let you continually scan cards in range and/or scan cards faster.
Make sure to use a transistor or a resistor on the LED/BZ output so you dont kill the pin.

Are EM4102 cards compatible with EM4001? Will this reader read an EM4102 tag?

Please I need a reader which has external antenna port

I just bought three more and they say ID-20LA. What is the LA?

My ID-20 is reporting {FF} over and over continuously, with, or without a tag being nearby. It also does not acknowledge any tag, it just streams {FF} at me. I think it's swearing at me. Did I do something wrong?

read range 200mm? The guy in your own tutorial says, and I quote, "3 inches, definately not 7 inches". That was in perfect ideal conditions. Weird specsheet.

Is ID-20 compatible with TI's MSP430 G2553?

Hello! I want to implement a solution for access control car to my building using RFID. It's possible to do with Arduino? What would I need more? Reader, writer, antenna, adhesive tags? Here circulating approx. 1000 vehicles per day. Thanks!

I am having read issues with the ID-20's serial starting with LV160912----

If it's on Arduino with breakout; I can't upload the code, I need to take the ID-20 out, upload the code then put it on.

If it's on Sparkfun RFID USB Reader; some readings stuck in loop and it tries to read after and after which brings out weird buzz and led light. Especially if you need to leave the rfid card on the reader for a bit.

I have four ID-20's bought last year which they have serial number as only numbers they work really fine with both breakout and rfid usb reader.

Does any have this kind of issue? I am getting so untrusty with ID-20's :/ or is there a production line issue with this last batch?

i'm having a hard time finding typical detect times. I am looking for a reader that can detect a tag that will pass by quickly. The detection window( when the tag will be within 2") will be 500ms or less. I can get the tag within a cm of the reader... Anyone with one of these willing to experiment or already have the anwser? Also, as an added challenge, i may end up having to attach the tag to the outside of a thin sheet of aluminum, about the same thickness as a pop can. How badly is that going to ding my detection range/ read time?

hello is there any password protected RFID tags out there? I need to protect my ID tages from copying.... thank you

I have two ID-12s. I have written extensive code to use the ID-12 for a door lock application. I have no problems there. However, when trying to modify my code to operate two separate doors with two separate ID-12s (one for each door), the code will not work. The idea is to only open the associated door, so I have to make the code tell me which ID-12 is reading the card. I have them as NewSoftSerials, but I am guessing my problem lies in that I am using two serials and I did not code it properly. They won't even return that they are available(). Can anyone direct me to example where more than one ID-12 is used within the same sketch?

This seams great. Small question where can I buy RFID cards? I want to use this for a door lock system so I need maybe 100 cards with unique ID?

I have recently purchased an ID-20 RFID reader with the Sparkfun tags and I am using it with an ATmega128 AVR. I am using interrupts on the USART line to detect when a tag is being inputted, but the interrupts are being triggered far too many times, even after the tag string has finished. Does anyone know why this could be happening?

Any chance certain cellphones might interfere with RF-ID readers? I have a continual serial read on an RF-ID reader hooked up to arduino ... I've had two cases where I was testing read values, and everything was working fine ... then someone stopped by in the vicinity, the the reading stopped (paused?) ... reading seemed to continue after they left the vicinity. Coincidence? or known problem? With mobile devices having all kinds of sensors, and the radios inside, I didn't want to rule out of the possibility. The strange thing is that I touched nothing ... the reader was working fine, then the person(s) showed up ... it stopped, they left, and it continued reading ... I work in my cube with a WP7 device on T-mobile, and I haven't had an issue ... Maybe these folks have a global Blackberry that emits a bunch of bad things? Not sure where 125kHz and cellphones fit in the spectrum ... guess I'll look that up to see if things make sense.

Hi, I have a question. What ID-20 pin must connect to the port RS232 of arduino directly?

PCB design, complete code and details of an electromechanical strikeplate for using one of these to control access to a home avialable at...
http://sheepdogguides.com/arduino/art3rfid1.htm
Does it work? I hope so... it is actually in use on my home. I get in just fine, and haven't had a burglar get in yet.

Beware of using this product with the 2mm standoffs that Sparkfun sells. I wanted to get the standoffs for this unit to be able to easily remove the module from the PCB, but I noticed that the pins do not fit snugly in the socket. As a result, the ID-20 slipped out of its mounts and then came back down into THE WRONG socket whilst handling! Doh! This smoked one of my ID-20's. It made a huge bubble on the top of the Id-20 that resembled a pimple. That one is dead, the day before a similar thing happened and quietly bricked that unit. I think I am going to forego the standoffs and solder these units directly to the board. So now, I am wondered if the company would make a SMD version. I am pissed that I did not take better care of those 2 ID-20 that I ruined. Lesson learned.

I bought 5 of these. I have them installed in a custom RFID card reader system. ID-20 -> PIC2455 -> Xbee Pro 60mW to a linux box running a custom daemon to reply back with an answer. The PIC then drops a relay to open a door. All was going great until last night we one of the readers just quit working. I am not sure why. It is the ID-20 module itself. It will not spit out anything. I am not sure how to troubleshoot the individual module since it is self-contained. I guess I just wasted $34.95. I hope the others do not just go bad. I am assuming that I misaligned the pins when plugging the unit back into the 2mm headers and I fried it. Anyone confirm my findings?

i think it is time to have in stock the RW RFID with the RW tags please.
We need them like hell!!!

Hello, I'm working with a ID-20 reader and the tags that you use in the "example video". No problems when I try to read one tag at a time. How you show in the same video, I can't read more than one tag in the same time. So, may have Sparkfun some solution to read more than one tag at the same time? Some tags or readers witch works with some anti collision protocol. I hope so, but if don't may you could help me to find some other place that I may can buy these solutions?
Thanks.

anyone know if this can read through a door?

why dont you have any ID-12RWs?

I have ID-20 I want to hookup this with PIC-18F4455. Have anybody tried something related with it ? I tried using RS232 communication protocol and used the getc() but not being able to get the right 12 bit data out of it.
Thanks in advance..

I work as a RFID technician at Avery Dennison.
We make these cards for Walmart and Dole for asset tracking, but at FCC 902 - 258 MHz.
Really doesn't seem to be hobbyist readers for HF tags yet, but I'd really like one.
Anyways has anyone verified the power output of this (dBm)?
Thinking of grabbing one of these little guys and boosting it.

i bought IR-20 with passive tag,when the reader get the information from the tag, i need to send the information to the the pic (dsPIC33FJ64GP802) by using SPI (Serial Peripheral Interface).
i really have no clue how to do that, email me at Khaled_alshaiji@yahoo.com, or answer me here, its my part of my project, please i need your help?

A guide, with code, to connecting this to an Arduino is available at...
http://sheepdogguides.com/arduino/art3rfid1.htm

Just curious, anyone use the sparkfun Project Case to house this reader? and if so how is the performance?
Thanks.

what type of ascii is the id20 reader reader using????

I'm having a tough time reading this chip from an Arduino Duemilanove. I have it connected as the datasheet says (confirmed at this page) wired to the Rx pin (pin 0) of the Arduino. Yet when I run the simple relay code
if(Serial.available() > 0) {
val = Serial.read();
Serial.print(val, BYTE);
}
I get bupkis in the Serial Monitor, or I get a constant stream of a single character (I think it was 'ƥ' at 9600bps). The relay blinks when the card is held close by.
Does it sound like I somehow burned out the chip? Is there any good way to test?
Thank you,
/m

I have used this component previously and really like it a lot. In my current project, I'm trying to move to a lithium polymer battery, and would like to run at 3.3V. However, the reader requires 5V. Do I need to have a voltage amplifier in order to power this device from 3.3V? Or is there a simple strategy to do this?
I guess alternatively I could run 2 cells in series to run a 5V system overall, but this introduces challenges in recharging the cells it seems.
Thanks for any advice or recommendations!

I see these are back in stock, not sure why I did not get a notification as I had signed up to receive one? Come to think about it, I have never received any notifications for any of the products that I have requested. Is this feature working?

Do you know when are you going to have more of these in stock?

can anyone provide me the c programming coding to code the id20 reader to show the tag id using pic 16f877a??the tag id must be shown in computer screen..tx

Hi, I've written a simple software for testing with Innovations ID-12 and ID-20:
http://www.settorezero.com/wordpress/software/rfid-reader/
More info on the download page. Hope it's useful, leave me some comments if you use it.
Greetings,
Bernardo Giovanni

Hi, I'm wiring this to my uC with the RFID breakout board. What exactly do pins 8 and 9 go to? Since I'm using ASCII, the datasheet says CMOS and TTL (inverted), which doesn't really help me...

i've bought rfid id20 reader...i've tried to interface the id20 with pic16f877a to light up leds..the id20 interface was done by connecting pin 9(id20) with rx(pic)..bt when tag id was detected id20, the led not on..can anyone help us regarding this??iz there anything else need to be interfaced between id20 and pic??<br />

question!, is this RFID gives a TTL USART output??, can you read this with a simple 16F877 PIC Microcontroller??
i may buy this for industrial proyects

I watched the video, but, the range that the ID 20 has is not the same as in the datasheet.
What is the real range the ID-20 has?

I wrote up my Arduino interface, very similar to the earlier post (which i didn't see until i was done). However if it helps anyone get going, here it is:
http://siliconfishtech.blogspot.com/2010/10/arduino-rfid-tag-reader.html
I did find it didn't read my HID tag from work.

Is is possible to separate multiple cards in range? Say I bring one card into range, keep it there and then bring another one into range. Will the second card get identified?

Is this able to monitor students within a classroom? Say a student walks in, tags themselves in, stays in a classroom for an hour and then able to tag themselves out? I.e. Is the reader able to read cards multiple times without resetting?

Is it possible to read encrypted cards / anyone have any thoughts on how this reader could be made more secure for a front-door entry application eg: paired with keypad and pin?

is it possible to write a tag? i mean, can i write data to the tag with this?

Is it possible to hook up a self build antenna to this RFID module?

I'm looking for an RFID reader, and my choice is between the the ID20 and the Parallax serial rfid reader http://www.parallax.com/Store/Accessories/Communication/tabid/161/ProductID/114/Default.aspx?SortField=ProductName,ProductName I am looking for one that will read tags through a door, which is 2" solid wood, but with thinner inset panels that are about 3/4". I could definitely fit either reader over one of these panels. Is it feasible to have a keychain-type RFID tag be readable through the door, and which reader would be best suited for this application?
Thanks a lot!!

When using the Reset line to re-read a transponder, wait at least 200ms after bringing the reset line high, then read, and then bring it back low.

great sensor. I was able to read cards through a notebook and a stack of paper.

What happens if you leave a card within its proximity? Will it continuously trigger and send the ID? or do you need to prod the reader to read a tag (if one is avaliable)?
Is it ok to leave RFID tags "powered" for long periods of time?

Can anyone confirm if this will read HID Indala cards?