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Get individual characters from integer value — Parallax Forums

Get individual characters from integer value

Hello everyone. I feel like this should be simple, but I do not know how to do this in spin.

A value is being sent via a serial port in the following format: "B12345," (I'm using the Extended fullduplex serial so , is the delimiter.)

I am then taking everything after the first character and converting it to an integer. So the integer will equal 12345. I need to split this integer into 5 different variables equaling 1, 2, 3, 4, & 5. How do I go about this?

Here's my code:
PUB readSerial | type, content, contentAdr, value, b

  repeat

    readBuffer := "0"
    serial.rxflush
  
    repeat until readBuffer <> "0"
      serial.RxStr(@readBuffer)

    type := readBuffer 'Take first character of string sent from computer to see type
    content := readBuffer[1] 'Take everything after the first character to get content
    contentAdr := @readBuffer[1]

    if type == "A"
      if content == "1"
        winValue := 1
      elseif content == "2"
        winValue := 2
    
    if type == "B"

      value := 0                                                    ' reset value                                                   

        repeat
          b := byte[contentAdr++]                                           ' get digit from string
          if ((b => "0") and (b =< "9"))                              ' if digit
            value := value * 10 + (b - "0")                           '  update value
          else
            quit

      testVar := value
      
      if testVar == 12345
        serial.str(string("matches/"))
      else
        serial.str(string("not a match/"))

      update(@digit1, @digit2, @digit3, @digit4, @dp)

testVar is equaling 12345 so I know the conversion is working properly. I just need to get digit1, digit2, etc to equal 1, 2, 3, etc.

Thank you in advance.

Comments

  • yetiyeti Posts: 818
    edited 2018-12-17 12:03
    You get a string like "31415", convert it by summing it digitwise times 10^n to an integer and then want to process individual digits?

    Why not just subtract "0" (= 48) from all nonzero bytes in the string to get a string of 5 values of 0 to 9 and pass these bytes to your update function?
  • Here's a little method that will convert a decimal string to a value. You need to capture your input and then pass a pointer (the address of using @) to the first digit in the string to this method. It will return when it hits a non-digit in the string (any delimiter).
    pub dec_value(p_str) : value | c
    
      repeat
        c := byte[p_str++]
        if ((c => "0") and (c =< "9"))
          value *= 10
          value += (c - "0")
        else
          quit
    
  • begin loop
    i=1
    digit = string-48
    value = 10*value + digit
    loop until your at the last character of string[]






  • AribaAriba Posts: 2,690
    Either you extract the digits from the received string:
      testVar := value
    
      digit1 := byte[contentAdr - 6] - "0"
      digit2 := byte[contentAdr - 5] - "0"
      digit3 := byte[contentAdr - 4] - "0"
      digit4 := byte[contentAdr - 3] - "0"
      digit5 := byte[contentAdr - 2] - "0"
    
    or you calculate the digits from the decimal value, this is more universally usable:
      testVar := value
    
      digit1 := value / 10000 // 10
      digit2 := value / 1000 // 10
      digit3 := value / 100 // 10
      digit4 := value / 10 // 10
      digit5 := value / 1 // 10
    

    Andy
  • Andy,

    Thank you so much.. This worked great.
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