GCBASIC documentation
RS232 (hardware)

Syntax:

    HSerPrint user_value [,1|2|3|4]  'Choose comport with optional parameter
                                       'Default comport is 1

    'Send a series of ASCII characters using the buffer called SerialPacket
    Dim SerialPacket as Alloc
    SerialPacket = 66, 105, 108, 108, 38, 69, 118, 97, 110, 13, 10
    HserPrint ( SerialPacket, 1 )  ’explicit to comport 1
    SerialPacket = 66,44,73,44,82,13,10
    HserPrint ( SerialPacket )  ’defaults to comport 1

Command Availability:

Available on all microcontrollers with a USART or UART module.

Microchip PIC supports USART1 and 2.
Atmel AVR supports USART 1,2,3 and 4.

Enabling Constants:

To enable the use of the USART these are the enabling constants.   These constants are required.  You can change the USART_BAUD_RATE and to meet your needs.  For addition USART ports use #define USARTn_BAUD_RATE 9600 where n` is the required port number.

    'USART settings for USART1
    #define USART_BAUD_RATE 9600
    #define USART_TX_BLOCKING
    #define USART_DELAY OFF

Explanation:

HSerPrint is used to send a value over the serial connection. user_value can be a string, integer, long, word or byte. HSerPrint is very similar to Print. The data will be sent out the hardware serial module.

HSerPrint will not send any new line characters. If the chip is sending to a terminal, these commands should follow every HSerPrint :

  HSerPrint 13
  HSerPrint 10

Example:

  'This program will display any values received over the serial
  'connection. If "pot" is received, the value of the analog sensor
  'will be sent.
  'Note: This has been adapted from the SerPrint example.

  'Chip settings
  #chip 18F2525, 8

  'LCD settings
  #define LCD_IO 4
  #define LCD_WIDTH 20                ;specified lcd width for clarity only.  20 is the default width
  #define LCD_RS PORTC.7
  #define LCD_RW PORTC.6
  #define LCD_Enable PORTC.5
  #define LCD_DB4 PORTC.4
  #define LCD_DB5 PORTC.3
  #define LCD_DB6 PORTC.2
  #define LCD_DB7 PORTC.1

  'USART settings
  #define USART_BAUD_RATE 9600
  #define USART_TX_BLOCKING
  #define USART_DELAY OFF

  'Potentiometer
  #define POT_PORT PORTA.0
  #define POT_AN AN0

  'Set pin directions
  Dir POT_PORT In

  'Create buffer variables to store received messages
  Dim Buffer As String
  Dim OldBuffer As String
  BufferSize = 0

  'Show test messages
  Print "Serial Tester"
  Wait 1 s
  HSerPrint "GCBASIC RS232 Test"
  HSerSend 13
  HSerSend 10
  Wait 1 s

  'Main loop
  Do
    'Get a byte from the terminal
    HSerReceive Temp

    'If Enter key was pressed, deal with buffer contents
    If Temp = 13 Then
      Buffer(0) = BufferSize

      'Try to execute commands in buffer
      If Not ExecCommand (Buffer) Then
        'Show message on bottom line, last message on top.
        CLS
        Print OldBuffer
        Locate 1, 0
        Print Buffer
        'Store the message for next time
        OldBuffer = Buffer
      End If

      BufferSize = 0
    End If
    'Backspace code, delete last character in buffer
    If Temp = 8 Then
      If BufferSize > 0 Then BufferSize -= 1
    End If
    'Received ASCII code between 32 and 127, add to buffer
    If Temp >= 32 And Temp <= 127 Then
      BufferSize += 1
      Buffer(BufferSize) = Temp
    End If
  Loop

  'Takes a sensor reading and sends it to terminal
  Sub SendSensorReading
    HSerPrint "Sensor Reading: "
    HSerPrint ReadAD10(POT_AN)
    HSerSend 13
    HSerSend 10
  End Sub

  'Will check the buffer for a command
  'If command found, run it and return true
  'If not, return false
  Function ExecCommand (CmdIn As String)
    ExecCommand = False
    'If received command is "pot", show potentiometer value
    If CmdIn = "pot" Then
      SendSensorReading
      ExecCommand = True
    End If
  End Function

For more help, see also HserPrintByteCRLF, HserPrintStringCRLF and HserPrintCRLF