DATA AQUISITION SYSTEM USING USB PORT

I need some key informations :-
1. We are giving 8-digital inputs through the digital input pins (33-40) of pic 18f4550 but we are not getting 8-LEDs flash at the output pins (19-22 and 27-30) of it.Why?
We have connected circuit as shown in the figure.
2.Is it necessary to program pic 18f4550 before using it ? OR Is it programmed by default ?
plz , reply me as soon as possible.

Hi,

Afraid you are only giving half a story so can only give half an answer.

If you have bought a project in Kit form then the supplier may have programmed the chip for you - however it is normally made very clear if they do program it for you, either with a full working program or a bootloader.

Assuming its not a kit, and you have bough the chip from a shop etc, then you will have to program the code into it - again do not know if it is part of a bootloaded system or not - you may need a full programmer or just the usb/ serial port of a PC.

You say the leds do not flash but you have not shown how you have connected them to the pic, they should also have a serial resistor on each led.
Also there is no clue as to what the inputs are - switches ??


Post a bit more info about you project hardware, software and any notes and perhaps we can help you more.