Skip to content

Hardware Research

Gabriel Blomberg edited this page Aug 2, 2024 · 3 revisions

RFID

RFID (radio frequency identification) is a protocol used to store and read/write information in small microchips embedded in stickers, identification cards, scanner tags etc.

Tags

An RFID tag is a small chip embedded in a substrate with an antenna. Energy is harvested from the antenna on scanning that powers the chip during scanning operation. Each tag has memory in terms of blocks that are 32 bits wide. For example, the most stocked (approximately one million in stock) RFID tag chip on digikey is SL2ICS5301EW/V7.

Data are stored in a non-volatile memory (EEPROM). The EEPROM has a memory capacity of 2048 bit and is organized in 64 blocks consisting of 4 bytes each (1 block = 32 bits). The higher 40 blocks contain user data and the lowest 24 blocks contain the unique identifier, EPC Memory, security, the write access conditions and special data like AFI and DSFID

Readers

The most stocked RFID scanner in digikey is the M24LR04E-RMN6T/2 that is an 8 pin SOIC chip interactable with I2C. This chip supports an I2C reader operation termed a "Fast Read Single Block" that can read each of the tag blocks above.

Microcontroller

Requirements:

  • Highly supported
  • I2C (rfid)
  • SPI (display)
  • GPIO (led)

Options:

  • ATMEGA328 (arduino)
    • The I2C interface supports only 32 byte read/write transactions at a time, that is incompatible with RFID scanning.
  • ESP32
  • STM32
    • Don't need WIFI

Operating System

Options:

  • FreeRTOS

  • Zephyr

Display

Adafruit 2.7inch Tricolour Display - 32$