Multiple serial port configuration

Conventional projects only support one serial port by default. If you want to use dual serial ports or even multiple serial ports, please download DoubleUartDemo sample, In this example, part of the serial port code is modified in the conventional project to support multiple serial ports.


The changes are described below.

  • Some codes of uart have been modified, so the serial port configuration in the project properties is invalid.
  • Please refer to the init() function in the jni/uart/UartContext.cpp file to modify the serial port number and baud rate.

    void UartContext::init() {
        uart0 = new UartContext(UART_TTYS0);
        uart0->openUart("/dev/ttyS0", B9600);
        uart1 = new UartContext(UART_TTYS1);
        uart1->openUart("/dev/ttyS1", B9600);
  • Send data to the designated serial port

      unsigned char buf[2] = {1, 1};
      sendProtocolTo(UART_TTYS1, 1, buf, 2); //Send to TTYS1 serial port
      unsigned char buf[2] = {0};
      sendProtocolTo(UART_TTYS0, 1, buf, 2);//Send to TTYS0 serial port
  • The way of receiving serial port data is the same as that of regular projects
    If you need to distinguish which serial port the data comes from, it is recommended to add a field to the SProtocolData structure to identify which serial port the frame comes from.

    modify uart/ProtocolData.h

    typedef struct {
          BYTE power;
          int uart_from; //From which serial port
    } SProtocolData;

    modify uart/ProtocolParser.cpp

       * Analyze each frame of data
      static void procParse(int uart, const BYTE *pData, UINT len) {
          // CmdID
          switch (MAKEWORD(pData[3], pData[2])) {
          case CMDID_POWER:
              sProtocolData.power = pData[5];
          sProtocolData.uart_from = uart; //Identify which serial port the frame comes from
          // Notify protocol data update

    Then in, you can use the uart_from field to determine which serial port the data comes from.

    static void onProtocolDataUpdate(const SProtocolData &data) {
        LOGD("onProtocol %d", data.uart_from);
        char buf[128] = {0};
        snprintf(buf, sizeof(buf), "Received serial port %d data", data.uart_from);

Sample code

For the complete code, see the DoubleUartDemo project in Sample Code

powered by Gitbooklast modified: 2021-05-28 12:00:31

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