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Home / 🗃️ unorganized / general notes / Serial Ports

Serial Ports

  • \(\text{SPI}\) (Serial Peripheral Interface)
  • \(\text{I}^2\text{C}\) (Inter-IC)
  • \(\text{I}^3\text{C}\) (Inter-Inter-IC)
  • \(\text{UART}\) (Universal Asynchronous Reception and Transmission)
    • Since it is asynchronous, no clock is needed
    • Just has RX and TX on both sides
  • \(\text{CAN}\) (Controller Area Network)
  • \(\text{USB}\) (Universal Serial Bus)
  • \(\text{RS-232}\) (Recommended Standard 232)

Serial Protocols

  • MAVLink

Notes

  • Older Raspberry Pi SoCs have 2 UARTs - a PL011 and a mini UART
  • On RPis with WiFi/BT Module, primary UART is mini UART
  • On RPis without WiFi/BT Module, primary UART is PL011
  • /dev/serial0 is a symlink to the primary UART
  • /dev/serial1 is a symlink to the secondary UART
  • /dev/ttyS0 refers to the mini UART
  • /dev/ttyAMA0 refers to the PL011
Note
  • On Raspberry Pi 4, they appear as ttyAMA0, ttyAMA1, ... , ttyAMA5, when enabled (0 is already enabled)
    dtoverlay=uart1 dtoverlay=uart2 dtoverlay=uart3 dtoverlay=uart4 dtoverlay=uart5
  • Serial Interaction Software (for Windows)
    • SSCOM
    • NetAssist (unknown origin)
    • HW-Group Hercules SETUP Utility
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