C# console application talking to Arduino via Bluetooth -

not whole lot here other doesn't work, , have no idea why.

the serial output on arduino nothing. output on c# code goes down waiting response , nothing.

the bluetooth card led on arduino goes green when start c# program there connection being made. nothing else.

arduino code

#include <softwareserial.h> //software serial port #define rxd 8 // pin bluetooth (bt_tx) transmit arduino (rxd) #define txd 7 // pin bluetooth (bt_rx) receive arduino (txd)  softwareserial bluetoothserial(rxd,txd); boolean light = false; void setup(){   serial.begin(9600); // allow serial communication via usb cable computer (if required)   pinmode(rxd, input); // setup arduino receive input bluetooth shield on digital pin 6   pinmode(txd, output); // setup arduino send data (output) bluetooth shield on digital pin 7   pinmode(13,output); // use onboard led if required. }  void loop(){    delay(1000);    if(light){       light = false;       digitalwrite(13,low);    }    else{      light = true;      digitalwrite(13,high);    }    //serial.println(bluetoothserial.available());    bluetoothserial.write("im alive");    if(bluetoothserial.read()>0){      serial.write(bluetoothserial.read());    } } 

core c# code

static void main(string[] args)         {         byte[] command = encoding.ascii.getbytes("it works");//{0x00,0x01,0x88};          serialport bluetoothconnection = new serialport();         bluetoothconnection.baudrate = (9600);          bluetoothconnection.portname = "com4";         bluetoothconnection.open();         if (bluetoothconnection.isopen)         {              bluetoothconnection.errorreceived += new serialerrorreceivedeventhandler(bluetoothconnection_errorreceived);              // declare 2 bytes vector store message length header             byte[] messagelength = { 0x00, 0x00 };              //set lsb length of message             messagelength[0] = (byte)command.length;               //send 2 bytes header             bluetoothconnection.write(messagelength, 0, messagelength.length);              // send message              system.threading.thread.sleep(2000);             bluetoothconnection.write(command, 0, command.length);              messages(5, ""); //this last thing prints before waits response.              int length = bluetoothconnection.readbyte();             messages(6, "");             // retrieve reply data             (int = 0; < length; i++)             {                 messages(7, (bluetoothconnection.readbyte().tostring()));             }         }     } 

okay there few issues hard see above attempt explain.

first, rx , tx on bluetooth card not go equals on arduino. go opposites.

example:

bluetooth card rx -> tx on arduino

bluetooth card tx -> rx on arduino

so if in photo of arduino above should painfully obvious pins 7 , 8 incorrect placement.

the next issue having poor connectivity.

the power , ground seem fine in above configuration. however, rx , tx connections need soldered in. otherwise poor connection.

once made changes above code worked flawlessly.

hope helps else having these issues!!