How can I connect Puck2.js to PN532 NFC/RFID ?

[espruino-discuss]

Posted at 2020-07-24 by user67655

Hi,
I have a PuckJS 2 with 2v06 and a PN532 NFC v3 module from Elechouse, connected as follows:

Puck.js_D28 to PN532_SCL,
Puck.js_D29 to PN532_SDA,
Puck.js_3V to PN532_VCC,
Puck.js_GND to PN532_GND,

Puck.js works fine and the red LED on the PN532 is also active.
Actually I use the Espruino Web Ide Tool, so:

1. I wrote the require("PN532"); on the right side;
2. sent with "Send to Espruino button" - the loading was OK (screen refreshed);
3. I tried to run it as described in the example for PN532 ( scl:B6 and sda:B6 changed to D28 and D29 );

I see now the following on the web console:
...
...
2v06 (c) 2019 G.Williams

I2C1.setup({scl:28, sda:29});
=undefined
var nfc = require("PN532").connect(I2C1);
={
i2c: I2C1
}
print(nfc.getVersion());
Uncaught InternalError: I2C Write Error 33281
at line 1 col 172
...sh(0);this.i2c.writeTo(36,b);b=this.i2c.readFrom(36,6);b[4]&...
^
in function "cmd" called from line 1 col 22
var a=this.cmd([2],12);return{chip:"PN5"+a[2].toString(16),f...
^
in function "getVersion" called from line 1 col 22
print(nfc.getVersion());
^

...
...

Can somebody help me, what could be the problem?
Thank you!

---

Attachments:

• 2020-07-24 16_56_48-PN532 NFC_RFID module - Espruino.png
  
• 2020-07-24 16_57_19-Espruino Web IDE.png

[gfwilliams]

Posted at 2020-07-24 by @gfwilliams

What you're doing sounds good. You could try software I2C just in case?

var i2c = new I2C();
i2c.setup({scl:D28, sda:D29});
var nfc = require("PN532").connect(i2c);

That'll be able to use the internal pullup resistors which may work if the PN532 doesn't have any.

Another issue could be the voltage. IIRC the PN532 needs quite a bit of power to get its coils working - it's possible that the 3v CR2032 doesn't supply enough power.

In that case, you'd just have to:

• Leave the VCCs connected
• remove the CR2032
• add an external 3.3v supply to VCC

[espruino-discuss]

Posted at 2020-07-24 by user67655

OK,thank you!