Tutorial 12 for Arduino: RFID Card Reading

[rodrigoolguinc]

How can you use more RFID antennas (with Softwareseral?). Thanks

[whilmer27]

where can i find the COM4 to see if my program is correct., or it is automatically pop out??? 

[whilmer27]

HI SIR!!!

Can you make a tutorials about FINGER PRINT SCANNER with adruino.., thanks in advance

[Sacmanis]

You do a byte by byte comparison of the Tag ID. I need to use an SD card to store and RFID tag ID along with a corresponding Xbee 'MY' number in a lookup table so that I can transmit data back to a given remote based on that combo. I assume it's possible to concatenate the bytes into a string and do a string compare?

[fede142857]

I'm the 100th like!

[TT1TTOne]

Great tutorial, thanks for your effort!

[MyOverflow]

I have to do it.

Obligatory XKCD for the comment for the line 21 in the read_rfid.pde file.

xkcd [dot] com/859/

In case you don't have that line numbered, it's this line:

Serial.print(0x87,BYTE); //Command (0x87 sets auto mode behavior

[sciguy14]

@MyOverflow That explains why I've been feeling uneasy ever since releasing this tutorial...

[jaysenstudios]

Could I use an ultrasonic sensor instead of a button to activate the rfid sensor?

[sciguy14]

@jaysenstudios Yes, but I wouldn't use it as a means to control current flow directly. Hook it up to the Arduino as an analog input, measure the value is software, and then use a wire to connect a digital out from the arduino into the enable pin of the RFID chip.

[l0rtto]

This might be a stupid question so hello and sorry!

When you're checking the byte in for loop, for example in this case something like this:

j_card=true;

for (i=0; i<5; i++) { if (data[i] !=jeremy[i]) j_card = false;

}

if (j_card==true) serial.println("All array elements are the same in data[i] and jeremy[i]")

Doesn't the j_card boolean always forget the previous value when executing the for loop again? So you're going to get "everything's correct" every time the last value is correct.

[sciguy14]

@l0rtto No it's correct. The j_card value is initially set to true, but the if statement can only possibly make it false. So once the one of the if statements in the for loops evaluates to false, it cannot be made true again on another run through the for loop.

[l0rtto]

@sciguy14 "So once the one of the if statements in the for loops evaluates to false, it cannot be made true again on another run through the for loop." That's pretty unambiguous. Thanks.

[sciguy14]

@l0rtto I can't tell if you're being sarcastic or not. I apologize if it was a poor explanation. To put it in other words, j_card=true appears only once in the code, before the for loop. Hence, once in the for loop, the j_card=false statement can set j_card to false, but there is no scenario that could set it back to true once it has already been made false, because j_card=true never appears in the for loop.

[punkdane]

hey, jeremy, how about making it a stand-alone project? add some LCD for the display,, will you help me doing it?

[sciguy14]

@punkdane I'm working on an LCD tutorial now - it will be easy to combine the two.

[lebeyes]

You are using Serial to talk to both the RFID reader and the computer. What I don't understand in the code is how you specify which you are talking to.

[sciguy14]

@lebeyes Sorry for not clarifying that. The jumpers on the Xbee only change where the Arduino RECEIVES data from. So, the arduino receives data from just the RFID card reader. But, when it sends data, it sends it to anything that happens to be connected to it's serial port's TX line. So, the computer, and the RFID card chip receive everything it sends. Conveniently, the RFID chip will just ignore any commands that it does not understand.

[XDark97]

Will you make a fun 16x2 LCD tutorial, becouse i want to build one and i dont know how. :(

Please Help Me.

[sciguy14]

@XDark97 Yes, I literally got one in the mail today.

[raghunitin]

Thanks Jeremy, thank you so much.... That was such an amazing tutorial.... I was just working on similar secret vault system, the only difference being I used a numpad keyboard and an LCD screen from which I read the password.... Thanks to you, now I'll use both of this in combination to create a super safe vault....

[sciguy14]

@raghunitin Awesome! Send me a link to the project when it's done :)

[raghunitin]

@sciguy14 With pleasure

[raghunitin]

30:29 Why not attach a proximity sensor near the door to do the closing part?

[raghunitin]

Why not while((val=Serial.read()) !=0xff); at the beginning?

[francisroan]

hey how old are u????? and wen did ya start playin with arduinos

[sciguy14]

@francisroan 21, a few years ago.

[wicket007]

Are you going to make a tutorial on GPRS shields? That would be great.

[sciguy14]

@wicket007 Yes I am.

[HPHQ10]

Wait are you afraid of the Anti-Christ using this technology since this is wanted in all the people around the world to control everyone just wondering because I would like to know your view on this since you know about it.

[sciguy14]

@HPHQ10 Wait, what?

[HPHQ10]

@sciguy14 Well if you havent been told well basically Christians believe the Anti-Christ will come into power after the Rapture and will use this same technology to track and and have all your information on it and if you dont accept it and put it in your right hand they will kill you.

[sciguy14]

@HPHQ10 In the event of the rapture, I will use electromagnetic induction to destroy the antichrist. Problem solved. Yay Jeremy! ...Also, again, wtf.

[HPHQ10]

@sciguy14 Well actually its going to be seven years after the rapture happens that the Anti-Christ will rein here on earth so but the first half of the time it is supposed to be pretty good but then the rest is just you a pretty much a slave to him and then Judgement day and if you choose to talk the RFID chip in your right hand then you will be sent to hell because you choose Satan over God and not going to Him. Though lol only if it was that easy. To just kill the most liked man on earth.

[sciguy14]

@HPHQ10 Wait... so I still can't figure out if you're screwing with me, since emotion can be hard to portray in youtube comments. Do you actually believe the things you're typing?

[HPHQ10]

@sciguy14 Actually yes since in the book of Revelation it explains everything im saying and after that as well.

I'm trying to be as serious as I can be since its my duty for everyone to know that Jesus is coming but no ones except for the Lord and that you can have Salvation if you do accept Christ as your one and only Savior.

[sciguy14]

@HPHQ10 I don't think youtube is the ideal place for you to be preaching religion. Please don't waste the time of people watching this video with things that are irrelevant, and frankly, ridiculous.

[HPHQ10]

@sciguy14 Well I believe God is anywhere and I am sorry to here you dont think have a relationship with God is relevant. Like I said you still can be saved if you accept Jesus Christ as your one and only Savior. Sorry if I was a disturbance to you and all of you subscribers. Though I do want to be a computer hardware engineer so thats why i watch your videos because I am interested in technology. Well on another note I would like to know how should I prepare to be an engineer? 

[sciguy14]

@HPHQ10 You are welcome to have your own beliefs. All I ask is that you let me have mine as well. They are unrelated to engineering anyways. Prepare to be an engineer by making things. Experiment, and make projects with your hands. Watching videos is good, but it's more important that you apply that knowledge to real projects.

[HPHQ10]

@sciguy14 Thank you for the start since I have already built my computer and just wanted to know from your experience so one more thing as far a colleges how should choose one because are there like scams or anything I should watch out for?

[sciguy14]

@HPHQ10 Apply to one that does research you find interesting.

[HPHQ10]

@sciguy14 Alright then thank you for the advise :)

[Z80Fan]

David: Open the door, Arduino

Arduino: I'm sorry, David. I'm afraid I can't do that.

:)

[sciguy14]

@Z80Fan Possibly the best comment ever.

[Z80Fan]

@sciguy14 Thank you!

[tharshan09]

Great tutorial! Glad you are back, looking forward to the next tutorial!

[RavenRof]

sweet, i was waiting for this ;)

[francisroan]

u changed ur room

[sciguy14]

@francisroan That happens a lot it seems... I'm living in NY city for the summer.

[francisroan]

after a very very long time.........

[RichyBTheking]

welcome back sciguy14 :)