2
\$\begingroup\$

I would like to set up communication between two Arduinos with a distance of 20 cm, but not more than 40 cm. I looked for an RFID solution, and I found a lot of PCBs which can be used to read and write to the RFID chip.

However I am wondering if it is possible to use such a PCB to exchange information. I need only up to 2 bytes/s transfer rate with a range of 20 cm. Can RFID be used for such communication?

\$\endgroup\$
3
  • \$\begingroup\$ Preventing it communicating for distances greater than 40 cm might be the biggest problem. \$\endgroup\$
    – Andy aka
    Jul 4, 2015 at 10:45
  • \$\begingroup\$ Ultrasound? It would be simple to send a small amount of information encoded as pulses of sound, and the range would be quite short. \$\endgroup\$
    – tomnexus
    Jul 5, 2015 at 9:28
  • \$\begingroup\$ This can be a nice solution as well, can you point out an out of the box solution, which can be used with arduino? Thank you. \$\endgroup\$
    – OHLÁLÁ
    Jul 6, 2015 at 12:51

2 Answers 2

5
\$\begingroup\$

The easiest way would be with the nRF24L01. These modules cost on ebay 1€. with these you can exchange data in higher speed and lower cost. You connect them via SPI, like with the RFID Module.

enter image description here

This is one of the most known designs out there. There are also many other designs with a PCB antenna or with an external one. Range with the Black one is about 60 Meters open Air with 8 bytes/s.

\$\endgroup\$
5
\$\begingroup\$

No. RFID is very much a master-slave relationship, in which the master (the RFID reader) supplies both power and timing to the slave (the RFID chip).

There's simply no way for two masters or two slaves to communicate directly with each other.

For such a short distance, optical communication would make the most sense. IR transceivers are commonly available and inexpensive, but I don't know if there are any Arduino-specific boards that incorporate them.

\$\endgroup\$
1
  • \$\begingroup\$ +1 for optical medium... I think we have enough RF noise without needing yet another device adding to it. \$\endgroup\$
    – user20088
    Jul 4, 2015 at 20:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.