octopus_reader

Read Octopus Balance with Arduino Nano + PN532 NFC RFID module

Connection Diagram:

  Nano             PN532 b
+------+          +------+
+  +5V +----------+ VCC  +
+  GND +----------+ GND  +  
+   A5 +----------+ SCL  +  
+   A4 +----------+ SDA  +
+------+          +------+

Description

The software initiate a InListPassiveTarget command to poll for an octopus card, then it send a "Read Without Encryption" command to the card with service code 0x117 to read 16 bytes from the card. The first 4 bytes (big endian) contain the adjusted balance.

The balance can be calculated by

(adjusted balance - 350)/10

Dependence

https://github.com/elechouse/PN532 Folder NDEF, PN532, PN532_I2C should be copied to libraries folder of Arduino

Note

1. I have to modify the buffer size of "Wire.h" and "twi.h" from 32 to 64, in order to make the program work
2. I tested with several octopus cards and octopus watches, but the program unable read some of them.