Cable for RFID Mifare RC522

Need Help With My Project
1

Hello (sorry for my english)
I’m starting to make a small alarm system for my home I thought to activate both Blynk and even an RFID 522 and up there all right.
I have a problem I do not know how to solve, I can not approach to RFID that Arduino Mega and located about 20 meters, I have basically connected to the RFID mega with 20 mt of you cat5 network cable but does not work …

someone has already made some tests with these RFID?
what is the maximum cable distance?
what is the best way to correct this problem?
thank you all

2

Sorry, this topic is completely not related to Blynk.
Maybe, some community member can answer.

3

We have used RFID with Mega’s and Nano’s and they were fine but we never tried with 20m of cable. I would try with 20cm first to be sure you have everything wired up ok.

4

thanks for answers, obviously with cable 20cm okay.
Alternatively with Blynk I can manage the RFID attached to a Arduino Nano and then serial 485 connected to mega? example:
Arduino Nano (slave) with RFID
20 meters serial cable
Arduino Mega (server)

This solution is correct? You can manage with Blynk?

http://yourduino.com/sunshop2/index.php?l=product_detail&p=323

5

I will say yes but what part is Blynk going to play in your project?

If you want to wave a Mifare card at your Blynk app in New York it’s not going to open the door to your London pad :slight_smile:

6

I understand you do not have to open the door … use already Blynk for other little things in the house and I also wanted to incorporate an alarm system for the house, alarm acensione with both RFID and even blink (because then with Blynk wanted to handle such Men night alarm that disables PIR sensors and maintain only the magnetic contacts of the windows) the rFID suits me because position it outside the house etc etc …

So in general although every project is different, what is the solution used in thousands of home automation / Alarm projects to connect various sensors eg: RFID-ULTRASOUND-PIR-TEMPERATURE SENSORS, since the cables these can not stretch to several meters?

thank you and excuse my English Costas (google translated)

7

@Tino the alarm systems I have seen using RFID and Arduinos have all the main pieces of hardware together with the required power supply so they don’t require long cables between the RFID and Arduino.

Perhaps if you gave a few more details we could advise how you might overcome some of the issues you have.

8

I think an NRF204 network would be quite handy to solve the problem of the long cables. Arduino nano + reader + NRF network and a central Mega or RasPi to manage it all.

9

Thanks for the kind advice hello

10

I use something similar in my Lego trains where the Arduino’s act as decoders and they transmit/receive their commands via NRF. I think I posted it on Instructables. It probably can be applied to this without too much hassle.

11

Thank you Lichtsignaal
because I have to go outside of the house with the ultrasonic sensor and different temperature of sensoni preferred to use a cable connection and no wi-fi.
Anyway, thank you have been very kind