ESP32 SPI

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Introduction to Serial Peripheral Interface.

SPI (Serial peripheral interface)

Introduction to SPI Interface
4-wire SPI devices have four signals:

  • CS : Chip select
  • SCLK: SPI Clock
  • MOSI: Master out, slave in
  • MISO: Master in, slave out

SPI Mode 0, CPOL = 0, CPHA = 0: CLK idle state = low, data sampled on rising edge and shifted on falling edge.

SPI Mode 1, CPOL = 0, CPHA = 1: CLK idle state = low, data sampled on the falling edge and shifted on the rising edge.

SPI Mode 2, CPOL = 1, CPHA = 1: CLK idle state = high, data sampled on the falling edge and shifted on the rising edge.

SPI Mode 3, CPOL = 1, CPHA = 0: CLK idle state = high, data sampled on the rising edge and shifted on the falling edge.

Multislave Configuration

Daisy-Chain Configuration

Examples of Serial Peripheral Interface

RC522 RFID Reader

Key Features:Datasheet

  • Supports ISO/IEC 14443 A/MIFARE and NTAG
  • Typical operating distance in Read/Write mode up to 50 mm depending on the antenna size and tuning
  • Supports MF1xxS20, MF1xxS70 and MF1xxS50 encryption in Read/Write mode
  • Supports ISO/IEC 14443 A higher transfer speed communication up to 848 kBd
  • Supports MFIN/MFOUT
  • Additional internal power supply to the smart card IC connected via MFIN/MFOUT
  • Supported host interfaces
    • SPI up to 10 Mbit/s
    • I2C-bus interface up to 400 kBd in Fast mode, up to 3400 kBd in High-speed mode
    • RS232 Serial UART up to 1228.8 kBd, with voltage levels dependant on pin
  • FIFO buffer handles 64 byte send and receive

Arduino Library: MFRC522

  • MFRC522.h
  • MFRC522.cpp
  • MFRC522Extended.h
  • MFRC522Extended.cpp

Examples>



This site was last updated June 18, 2023.