I bought some RFID readers and plan to experiment with them soon. Here are my notes.
RDM6300
- Working frequency: 125 KHz
- Reads EM4100 compatible tags
- Interface: UART, Baud rate 9600
- Read Range 20-50 mm
- Operating voltage: 5V DC
Arduino libraries:
RFID-RC522, Mini RFID-RC522
- Working frequency: 13.56 MHz, ISM Band
- ISO 14443A standard tags. Supports Mifare1 S50, Mifare1 S70, Mifare Light, Mifare UltraLight and Mifare Pro, Mifare Desfire.
- Interfaces: SPI 10Mbps, I2C, UART
- Operating voltage: 3.3 V (Logic pins are 5V tolerant)
- Read Range – 50 mm
Can be programmed to generate an interrupt (IRQ), allowing the module to alert us when a tag approaches it.
Arduino libraries:
Connecting Raspberry Pi Pico
| RS522 pin | Pi Pico pin |
| MISO | GPIO16 |
| SS | GPIO17 |
| SCK | GPIO18 |
| MOSI | GPIO19 |
| 3.3V | 3.3V |
| GND | GND |
Dump info examples:
NFC module V3 PN532
- 13.56 MHz
- Interfaces: I2C, SPI, HSU (High-Speed UART)
- Mifare cards 1k, 4k, Ultralight and DesFire ISO / IEC 14443-4 cards such as CD97BX, CD light, Desfire, P5CN072 (SMX) Innovision Jewel Cards as IRT5001 card. FeliCa cards such as RCS_860 and RCS_854. P2P communication with peers, NFC with Android phone
- On-board level shifter, Standard 5V TTL for I2C and UART, 3.3V TTL SPI
- Read Range 50-70 mm
Arduino libraries:
- https://github.com/adafruit/Adafruit-PN532
- https://github.com/DFRobot/DFRobot_PN532 I2C only
https://github.com/elechouse/PN532couldn’t get SPI to work!
MIFARE Classic 1K Memory Layout
The tag’s 1K memory is organized into 16 sectors (from 0 to 15).
Each sector is divided into 4 blocks (blocks 0 to 3).
Each block can store 16 bytes of data (from 0 to 15).
The last block of each sector is called a Sector Trailer. It contains information called Access Bits that provide read and write access to the remaining blocks in the sector. This means that only 3 blocks of each sector (Blocks #0, #1 and #2) are actually writable, in other words only 48 bytes per sector are available for use.
Block #0 of Sector #0 is called Manufacturer Block which contains IC Manufacturer data and a Unique Identifier (UID).
Tauno Erik 
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