sending serial data-am i missing something?

ok, so i have a C# program (can be converted to C++ if needed) and i have this:

struct RoboInfo
            public Double Speed; //-100 to +100
            public Double SteeringDirection; //-5 to +5
            public Double Tilt;//0 to 20
            public Double Pan;//-5 to 5
            public bool Shoot;//true or false

i want to send that to the arduino, i know i can do this:
SerialPort.Write(byte[], 0, 5); (not acutla code, but you get the point...

but the arduino gets the ASCII values, is there any EASY was to just read the data i send into a byte array?????

I can't help with your specific question but I can provide some general guidance...

  • Byte ordering will very likely be different. A Double in C# is probably stored "backwards" from the way it's stored in the Arduino. You will probably have to swap the bytes for each Double.
  • Byte alignment is probably different. In C# the elements are very likely 8-byte aligned while in the Arduino the elements are not aligned (byte aligned). Shoot is the element most likely to be a problem. You may have to pad the structure on the Arduino side (or make the structure "packed" on the C# side).

well, i can make them all ints, or bytes, thats not an issue, if i had like

byte[] Data=new byte[5];
Data[0]=100;//speed, 0=full reverse, 100=stop, 200=fulll forward
Data[1]=5; //0 is full left, 5 is center, 10 is full right
Data[2]=0; //0 is level, 20 is full up
Data[3]=5; //0 is full left, 5 is center, 10 is full right
Data[4]=0; //0 is not shooting, 1 is shooting

is there a way to send that to the arduino, into another byte array?

See what you can do with this. It’s quick and dirty, but it looks like you know what you’re doing, maybe it’ll give you some ideas. In particular notice what the integer value does as you write to the high and low bytes.

The BitConverter class may be useful if you need to send multi-byte values. You can find EndianBitConverter implementations that can make things a bit easier.

Arduino Sketch:

struct Info
  byte byteVal1;
  byte byteVal2;
  boolean boolVal;
  int intVal;
} info;

byte* infop = (byte*)&info;

void setup()
  // start serial port at 9600 bps:
  establishContact();  // send a byte to establish contact until receiver responds 

void loop()
  if (Serial.available() > 0) {
    // Get the input
    byte inByte =;
    // check for special value
    if (inByte == 'r')
      // reset the input pointer
      infop = (byte*)&info;
      // store the input and advance the pointer
      *(infop++) = inByte;

    // Print the current state of the structure

void showStruct()
    Serial.println(info.byteVal1, DEC);    
    Serial.println(info.byteVal2, DEC);    

    Serial.println(info.boolVal, DEC);    

    Serial.println(info.intVal, DEC);    

void establishContact() {
  while (Serial.available() <= 0) {
    Serial.print('A', BYTE);   // send a capital A

C# app

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO.Ports;

namespace ConsoleApplication2
    class Program
        static void Main(string[] args)
            SerialPort port = new SerialPort("COM5");
            port.BaudRate = 9600;

            Console.WriteLine("type 'x' to exit.");

            while (true)
                if (port.BytesToRead > 0)
                    Console.Write( (char)port.ReadByte());

                if (Console.KeyAvailable)
                    ConsoleKeyInfo key = Console.ReadKey(true);
                    // use 'x' to close port and exit
                    if (key.KeyChar == 'x')
                        Console.WriteLine(string.Format("<-{0}({1})", (byte)key.KeyChar, key.KeyChar));