Tutorial 8 - how to enable Serial Communication

Using Ubutnu Hevelopment Host:

  1. minicom is the popular program to talk to the external RS-232 devices. Please enter the following command to install it

    $ sudo apt-get install minicom

  2. After installed, please execute this command to open this program

$ sudo minicom -s
  1. Set up the serial port connection( The default baud rate for serial port connections is 115200 ) and save it.

![Getting Started With Minicom - Getting Started With Minicom](Tutorial 8 how to enable Serial Communication.assets/Minicomserialport.png)

Using Windows Development Host

Please download puTTY (The default baud rate for serial port connections is 115200)


Serial port Connections

image-20201102154524948

There are four wires: red-power, black-ground, white-RX into USB port, and green-TX out of the USB port

Note: The red wire is not connected to the voltage as I-Pi is already connected with the power source.


PL2303HX Debug Port serial cable

image-20201102153022896

  • Single-chip USB to Serial (RS232/RS422/RS485) asynchronous serial data transfer interface
  • Fully Compliant with USB Specification v2.0 (Full-Speed)
  • USB-IF Logo Compliant with TID 40000100
  • UHCI/OHCI (USB1.1), EHCI (USB 2.0), xHCI (USB 3.0) Host Controller Compatible
  • Integrated USB 1.1 Transceiver and 5V to 3.3V Regulator
  • Integrated 96MHz clock generator (No external crystal required)
  • Integrated OTPROM (One-Time Programming ROM) – no external EEPROM required.
  • Supports USB to RS232 Serial UART Interface
  • Full-duplex transmitter and receiver (TXD and RXD).
  • Supports RS-422/RS-485 like serial interface (TXD, DTR_N, and RTS_N pins should be externally pulled-up to 5V)
  • Extensive Flow Control Mechanism
  • Adjustable high/low watermark level
  • Automatic hardware flow control with CTS/RTS or DSR/DTR
  • Automatic software flow control with XON/XOFF
  • Inbound data buffer overflow detection
  • Configurable 512-byte bi-directional data buffer
  • 256-byte outbound buffer and 256-byte inbound buffer
  • 128-byte outbound buffer and 384-byte inbound buffer
  • Supports Remote Wake-up from RS232 input pin signals (RI, RXD, DSR, DCD, CTS)
  • Four (4) General Purpose I/O (GP0, GP1, GP2, & GP3) pins and Four (4) Auxiliary General Purpose I/O (RI_N, DSR_N, DCD_N, & CTS_N) pins.
  • Supports Windows Selective Suspend by OTPROM configuration (Enable Remote Wakeup)
  • Suspends power of chip when idle (COM port is closed)
  • Provides royalty-free USB to Virtual COM Port drivers for Windows, Mac, Linux, Android
  • -40 C to 85s degrees C Operating Temperature
  • Small footprint 28-pin SSOP or 32-pin QFN IC packages (RoHS compliant and Pb-free Green Compound
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