I just want to Broadcast UDP packets out on a local network, what destination address do I use
You could use the limited broadcast address 255.255.255.255, however it is best to use the correct IP broadcast address of your local network segment (more successful in my own experience). You can calculate the correct broadcast address, see here.
Which kind of device are you communicating with ? USB doesn't work like a serial port: you don't have access directly to the port but instead you get the handle of a driver. This driver is shipped with the device you want to communicate with and manages all the communication with the device.
To get the handle of the driver, simply call CreateFile supplying the correct driver name, then you should be able to use ReadFile and WriteFile. You can also do some more specific stuff by calling DeviceIOControl (in which you can pass some specific IO code which is dependent of your driver).
So, if you want more help, you'll need to give a lot more information (which device do you try to access, if you have documentation with it, ...).
don't tell me that you don't find the way to implement the secant-method or bisection method!
You have only to implement the algorithm:
ask for a function f(x) and for the borders x1 and x2.
check that sign(f(x1)) != sign(f(x2)) .
Then compute x3 inside the interval (x1, x2). This according on the algorithm, in bisection case x3=(x1+x2)/2,....in secant method it's only the point where the line from (x1,f(x1)) to (x2,f(x2)) intercept the x-axe.
then choose the new interval (or x1-x3 or x3-x2) according on where is the root.
Then start again on the new interval.
Do this 10000...000 times and stop it. Or stop when the interval is "too small".
i have worked very enough with serial port(RS 232).
but never heard of the cts pin and dcb.
atleast for my information please educate me regarding those.
then i will try to solve if it in my perview.
I use PCOMM library for sending and receiving data using serial port.
functions are like
sio_ioctl(); to define the port settings.
soi_iqueue();to find weather any data is there in the port.
may be i can help you if you are also using these libraries and functions.