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Pn532 compatibility with Raspberry Pi 3 / zero with I2C?
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Pn532 compatibility with Raspberry Pi 3 / zero with I2C?

by gust0208 on Tue Jul 27, 2021 6:11 pm

Hello,

I have had success with using the SPI bus to communicate with the PN532 and my raspberry pi 3 and zero. My question is in the documentation for the PN532 it states that the I2C bus is not reliable for use on the Raspberry Pi [https://learn.adafruit.com/adafruit-pn532-rfid-nfc/python-circuitpython].

My question is if this is still true? It seems surprising given the Stemma QT hat for the raspberry pi using the I2C bus exists. I love the ease of use with the Stemma QT connection, but didn't want to proceed with my project if it would lead to instability or weird errors down the road.

Thanks,
Tom

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Re: Pn532 compatibility with Raspberry Pi 3 / zero with I2C?

by dastels on Tue Jul 27, 2021 7:38 pm

It's not ALL I2C devices, but this one in particular. It's not really surprising as the Pi isn't as microcontroller board. It's not designed for hard real-time projects and sometimes low level hardware interfaces don't work so well. SPI does work well for this breakout so why not just use SPI?

Dave

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Re: Pn532 compatibility with Raspberry Pi 3 / zero with I2C?

by gust0208 on Wed Jul 28, 2021 2:54 pm

dastels wrote:It's not ALL I2C devices, but this one in particular. It's not really surprising as the Pi isn't as microcontroller board. It's not designed for hard real-time projects and sometimes low level hardware interfaces don't work so well. SPI does work well for this breakout so why not just use SPI?

Dave


Thanks for the reply. The documentation was not clear that the I2C concern was specifically for the PN532. As I put in my post, the reason I was asking is that I like the ease of the Stemma QT connections and just overall simplicity for wiring. But, as you said, the SPI works, so I will go ahead with it.

gust0208
 
Posts: 22
Joined: Wed Oct 14, 2015 11:37 pm

Please be positive and constructive with your questions and comments.