*char parameter problems

Projects Programming
1

Hello,
I have the code below in which function void PutStringValue(byte Param)
doesn't return "" value according to each case. from my obesrvations RetStr = ""; dosen't work all the times
Any idea why?
And another strange thig is that when i call the function eg. PutStringValue(10), the Param in the function parameter is 0010 or 010
so..any idea?

I'm using an arduino uno.

char *RetStr;
void DrawMenu()
{
  byte Len;
  if (CrtMenu.ID != pMenu.ID)
  {
    lcd.clear(BLACK);
    pMenu.ID = CrtMenu.ID;
    pMenu.Pos = 0;
    for(byte i=0; i < CrtMenu.Size; i++)
    {
      PutStringValue(CrtMenu.Item[i].fParam);
      Len = 16 + strlen(CrtMenu.Item[i].Label) * 8;
      if(i == CrtMenu.Pos)// If i is the current position, then write the string on white on black bg
      {
        lcd.drawText(CrtMenu.Item[i].X-8, CrtMenu.Item[i].Y, ">", 0, hText, txtBGColor);                        
        lcd.drawText(CrtMenu.Item[i].X, CrtMenu.Item[i].Y, CrtMenu.Item[i].Label, 0, hText, txtBGColor);
        lcd.drawText(CrtMenu.Item[i].X + Len, CrtMenu.Item[i].Y, RetStr, 0, hText, txtBGColor);
      }
      else
      {
        lcd.drawText(CrtMenu.Item[i].X, CrtMenu.Item[i].Y, CrtMenu.Item[i].Label, 0, nText, txtBGColor);
        lcd.drawText(CrtMenu.Item[i].X + Len, CrtMenu.Item[i].Y, RetStr, 0, nText, txtBGColor);
      }
    }
  }
  els
  {
    if(CrtMenu.Pos != pMenu.Pos)
    {

      Len = 16 + strlen(CrtMenu.Item[pMenu.Pos].Label) * 8;
      lcd.drawText(CrtMenu.Item[pMenu.Pos].X-8, CrtMenu.Item[pMenu.Pos].Y, ">", 0, txtBGColor, txtBGColor);
      lcd.drawText(CrtMenu.Item[pMenu.Pos].X, CrtMenu.Item[pMenu.Pos].Y, CrtMenu.Item[pMenu.Pos].Label, 0, nText, txtBGColor);
      PutStringValue(CrtMenu.Item[pMenu.Pos].fParam);
      lcd.drawText(CrtMenu.Item[pMenu.Pos].X + Len, CrtMenu.Item[pMenu.Pos].Y, RetStr, 0, nText, txtBGColor);

      Len = 16 + strlen(CrtMenu.Item[CrtMenu.Pos].Label) * 8;
      lcd.drawText(CrtMenu.Item[CrtMenu.Pos].X-8, CrtMenu.Item[CrtMenu.Pos].Y, ">", 0, hText, txtBGColor);                      
      lcd.drawText(CrtMenu.Item[CrtMenu.Pos].X, CrtMenu.Item[CrtMenu.Pos].Y, CrtMenu.Item[CrtMenu.Pos].Label, 0, hText, txtBGColor);
      PutStringValue(CrtMenu.Item[CrtMenu.Pos].fParam);
      lcd.drawText(CrtMenu.Item[CrtMenu.Pos].X + Len, CrtMenu.Item[CrtMenu.Pos].Y, RetStr, 0, hText, txtBGColor);
      pMenu.Pos = CrtMenu.Pos;
    }
  }
}
void PutStringValue(byte Param)
{
  RetStr = "";
  switch(Param)
  {
    case ROM_Sequence://Sequence Off=0/On=1
      if (ROM_VAL[Param].Value == 0)
       RetStr = "Off ";
      else
        RetStr = "On  ";
    break;
    case ROM_S1_TrigAt://Sensor1 triggerat0=Low/1=High Value
    case ROM_S2_TrigAt://Sensor2 trigger at 0=Low/1=HighValue
      if (ROM_VAL[Param].Value == 0)
        RetStr = "High";
      else
       RetStr = "Low ";  
    break;
    case ROM_D1_TrigBy://Device1 is triggered by 0=None/1=Sensor1/2=Sensor2
    case ROM_D2_TrigBy://Device2 is triggered by 0=None/1=Sensor1/2=Sensor2
      switch(ROM_VAL[Param].Value)
      {
        case 0:
          RetStr = "None";
        break;
        case 1:
          RetStr = "Sen1";
        break;
        case 2:
          RetStr = "Sen2";
        break;
      }
    break;
    case ROM_D2_Mode://Device2 0=None,1=Camera,2=Flash,3=Split
      switch(ROM_VAL[Param].Value)
      {
        case 0:
          RetStr = "None";
        break;
        case 1:
          RetStr = "Came";
        break;
        case 2:
          RetStr = "Flas";
        break;
        case 3:
          RetStr = "Spli";
        break;
      }
    break;
    case ROM_SDelay://Sequence Delay 0-9999[ms] between Shutter1 and Shutter2 if ROM_Sequence=1
    case ROM_Bulb://Exposure in Bulb Mode 0-3599[s]
      itoa(ROM_VAL[Param].Value, RetStr, 10);
      //sprintf(RetStr, "%d", ROM_VAL[Param].Value);
    break;
    default:
      RetStr = "";
  }
   RetStr = "";
 // Serial.print(" RetStr => ");Serial.print(RetStr);Serial.println();
}
.............................
2

The second argument of itoa needs to be a pointer to a buffer of sufficient size:

static char buf[6];
/* ... */
RetStr = itoa(ROM_VAL[Param].Value, buf, 10);

Oliver

3

I did try that but with a buffer[2]because may int value will be max 9999 value

RetStr = itoa(ROM_VAL[Param].Value, buf, 10);

4

The string "9999" will occupy 5 bytes (including '\0'). So, you need buffer[5].