memory and timer questions for pic18f4550, inputs from GUI

hi everyone,

can someone please guide me on my project.

the scenario is this,

i will be having a GUI(Visual C++), that will prompt the user to enter the time/date that he wants to on/off a certain device via USB. since my protocol will be USB,so the data entered by the user will be passed on the pic microcontroller(PIC18f4550) via USB and the pic will be responsible to decrementing the time that the user input on the GUI. and the module can stand alone even if the GUI is not present as it was an independent device outputting on/off depending on the timer. its like your burning on the data to the pic18f4550 and setting that data as a count down/timer to on/off a certain device.

for example, ill input to on a certain device for 8 hours,and after pressing the start, the data from the GUI which is 8 hours, will be passed on the pic and the pic itself will execute/ decrement the 8 hours until it will become 0.

so,my problem is how to passed on the data from the GUI to pic18f4550 that will end up as a count down and if its 0, it will on/off a certain device.

ill be using mplab c18 as the compiler.

thanks for the advance replies

hi dabby21
connect to usb port have some problem ( for this you need know basic of usb Protocol and ... )
so , i offer USB TO RS232 Converter chip like ft232 (FT232R datasheet)
by this chip you can write your GUI program for COM port (serial port in visual c++)
in pic18f4550 program you can get Transmit variable from COM port and use that for on/off a certain device (MPLAB C18 & USART / SERIAL PORT EXAMPLE)

hi 1nafar,

thank you for replying, regarding how to connect the usb port and GUI, ive already successfully done it, and made a program that turn on the LED and get the status of a switch if its turn on or off. what my problem is how to pass on the data on the GUI that the user input to the USB module,which the pic microcontroller(PIC18F4550) located. my assumption are timer and memory allocation for pic is necessary regarding my problem but im not sure if im correct and honestly, i dont know how timer and memory works for microcontroller. i mean, its easy how to manipulate and there are many examples on timers with pic, but mine is passing the data which coming from GUI, to the PIC. thats the idea but i dont know how it will be done.

---------- Post added at 01:14 ---------- Previous post was at 01:07 ----------

Programmable digital timer switch using a PIC Microcontroller :Embedded Lab

above is a good example but the input itself is on the module.

so basically, this is how it works, but the input is coming from the GUI, passed the data to the pic and same function. the pic execute the desired time that the user wants which input it from the GUI.