ex_RS485Send.nxc

This is an example of how to use the RS485Control, RS485Disable, RS485Initialize, RS485Enable, UseRS485, RS485Uart, RS485Status, RS485Write, RS485SendingData, SendRS485String, SendRS485Bool, SendRS485Number, TextOut, and Wait functions.

// RS-485 sender program

inline void WaitForMessageToBeSent()
{
  while(RS485SendingData())
    Wait(MS_1);
}

task main()
{
  // configure the S4 port as RS485
  UseRS485(); 
  // make sure the RS485 system is turned on
  RS485Enable();
  // initialize the UART to default values
  // low level API function call (allows changing UART settings)
  RS485Uart(HS_BAUD_DEFAULT, HS_MODE_DEFAULT);
//  // hi level API function call
//  RS485Initialize();
  Wait(MS_1); // make sure everything gets turned on okay
  int i;
  byte buffer[];
  while (true) {
    string msg;
    msg = "goofy " + NumToStr(i);
    TextOut(0, LCD_LINE1, msg);
    
    // send the # of bytes (5 bytes)
    byte cnt = ArrayLen(msg);
    SendRS485Number(cnt);
    WaitForMessageToBeSent();

    // wait for ACK from recipient
    until(RS485DataAvailable());
    RS485Read(buffer);

    // now send the message
    SendRS485String(msg);
    WaitForMessageToBeSent();

    // wait for ACK from recipient
    until(RS485DataAvailable());
    RS485Read(buffer);

    i++;
  }
  // disable RS485 (not usually needed)
  RS485Disable();
}