HSerGetNum myNum    ‘Gets a multi digit number  from USART 1
  HSerGetNum myNum,1  ‘Get a multi digit number from USART 1
  HSerGetNum myNum,2  ‘Get a multi digit number from USART 2
When the variable type is a word the number range is 0 to 65535
When the variable type is a long the number range is 0 to 99999

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.


This command will read a multi digit number received as ascii chars followed by a CR from an external serial source using a hardware serial module. The command checks that only numbers are input disregarding other characters while waiting for the ending <CR>. It can be used only as a subroutine.


  'This program receives a number and CR from a PC terminal and sends it back on both usarts
  #chip 18f26k22, 16

  'Set the pin directions
  #define USART_BAUD_RATE 9600
  #define USART2_BAUD_RATE 9600

  'Init pins
  #define SerInPort PORTc.7    'usart1 in
  #define SerOutPort PORTc.6    'usart2 out
    'Set pin directions
    Dir SerOutPort Out
    Dir SerInPort In
    Dir PORTB.6 Out            'USART2 out
    Dir PORTB.7 In            'USArt2 in
    Dir PORTB.0 Out            'leds for testing
    Dir PORTB.1 Out            'leds for testing
    Wait 100 Ms

  Dim myNum as Word
  'Main body of program commences here.
  'Message after reset
  HSerPrint "18F26k22"

  'Main routine
  Do forever
    'wait for char from UART
    'HSerReceive InChar
    HSerGetNum myNum,2    'from usart 2
    HSerPrint myNum,1            ' send out usart 1
    HSerPrint myNum,2        'send out usart 2
    HSerPrintCRLF 1,2        'send one CRLF out usart 2
    HserPrintCRLF 1,1        ‘send one CRLF out usart 1

Example: This program receives number on serial port 1 and displays. This example shows using a Long as the input variable.

Therefore, the result is in the range of 0-99999. The example also shows how to detect a buffer overrun by testing the HSerInByte variable.

    #chip mega328p, 16

    #define USART_BAUD_RATE 9600
    #define USART_BLOCKING

    Dim myNum as Long  ' range 0 to 99999
    HSerPrint "Restarted"

      HSerGetNum myNum
      HSerPrint myNum

      if HSerInByte <> 13 then
          HSerSend 9
          HSerPrint "Error buffer overrun"  'You should handle error appropiately
      End if

See also HSerReceive and HSerGetString