Connecting to a computer...

[DigitalKnight]

For my cap-stone class my team is building a sensor system, and we would like to write the software in such a way so that we can up-load the data to a computer after a set time. My question is this: Would it be easier to use USB or the use a parallal port to comunicate with the PC?

Thanks for any input.

DK.

[Aedan]

Good question. How much data do you have to transfer? Does your sensor network have a dedicated controller of it's own?

If you're using Windows NT/2000/XP, then you're shielded from the hardware by the OS. You then have to place another layer of software (GiveIO for example) in the mix in order to be able to get at the port hardware. It's certainly doable however!

Alternatively, you could use the serial port, which is fairly easy to interface to, isn't that fast, but doesn't require special drivers.

For USB, there's a number of devices and ActiveX controls that can make your life much easier. USB also nets you reasonable speeds. There are some good USB to FIFO chips out there. FTDI do some nice components that shouldn't be too hard to get hold of. The FT232BM is pretty nice - see this page for more details on it.

[DigitalKnight]

I think that it'll be around 2 mb of data. The sensor is a VOM circuit that records a voltage and current reading every five seconds for a couple of days. Right now I am thinking of using a CPU, some flash memory chips, and VOM circuit, and maybe if need be a I/O controller. Given the small amount of data to be moved I don't think that the speed of a USB connection is needed, I'm just looking for the easiest connection option possable, as most of our time will be spend on the sensor package (I hope).

[Aedan]

If your controller has a UART, you can throw data out it's UART to the PC's serial port. If it doesn't, you can always bitbang the stuff up to the PC.