Andras,
Couldnt a simple RS-232 to USB chip (ex.
Most PICs, AVR, etc have the RS232 built in, and you dont need an external bus or any additional I/Os.
Im not sure about the "host" thing.
Ben
The reason I went for fpga was to have wireless networking (802.11)
> Actually, the sensors are 3-4 miles apart, I need the data until a
> base station from where I will transfer the data to the internet.
> the base station is located in the filed and will be 1-2 miles distant
> from each sensor. So how do I transfer (in realtime) the data until the
> base station from the sensor. Is it possible with PCI micro.
> Please suggest me if there is a better solution other than fpga cpu
> for doing this (wireless networking).
Doing wireless with FPGA is not easier (nor harder) than with CPUs or MCUs. You probably will end up using some kind of off-the-selves wireless card and connect it to your custom application. Of what I understand of your application probably a wireless USB card would be the best for your application. Processing power is not an issue in your case. In that case you need to choose (or implement) a USB host controller but for control even an
8-bit CPU (PIC or AVR or whatever) should be adequate. I don't know of any
8-bit micro that has an USB host (not function!) controller, but there's a USB interface IC from Cypress, the SL811HS, that can be used as both a host and a slave controller. So, my suggestion would be:
- Use an 8-bit microcontroller with an external bus (68HC11 from Motorola) or one with enough of I/O pins (ATmega from Atmel) and probably a with built-in A/D for the pressure sensors.
- Use the SL811HS from Cypress to implement the USB host controller
- Stick a wireless USB adapter to the unit to implement wireless
- For 1-2 miles you probably need high-gain, directed antennas so choose an adapter that has external antenna connectivity.
Regards, Andras Tantos