Re: [Discuss-gnuradio] Low-cost hardware options

[Moeller]

On 15.01.2011 03:10, Marcus D. Leech wrote:
> I've posted my latest thoughts at:
> 
> http://www.sbrac.org/files/digital_receiver2.pdf
> 
> This version has some BOM cost estimates for most of the items, and 
> shows a new

I counted $75, let's say $100 (incl. voltage conrollers, R/C),
plus $50 for PCB (if we order more units). Is $150 a realistic value
for material and PCB?

Plus $150 to $250 for a cheap FPGA board, or even a cheaper USB board.
Not too much for a hobby instrument.

But I would suggest an option to switch to a second input,
directly into the ADC, to cover the range DC to 10 MHz, or to attach
an external RF, IF (e.g. from an amateur radio).
Or a second board without mixer, just replacing it on the FMC connector,
similar to the USRP daughterboard system.

>    ADC by a factor of 3, but it would eliminate the need for a FPGA on 
> the "host interface"
>    side of that FMC connector.  So, you're trading a more expensive 
> digital-receiver section
>    for a cheaper "host interface" section.  For example, by using an 
> AD6652, one could
>    easily conceive of nothing more than a cheap EZ-FX2 USB-2.0 
> implementation on
>    the host-interface side.

I looked at the CY7C68013 EZ-USB FX2 data sheet.
Is it true that we wouldn't need any FPGA glue logic to control
the receiver, for the frequency synthesizer, flow control etc. ?
There are lots of IO pins and busses on the FX2.
The embedded 8051 µC could be used to control the receiver.

> For at least USB-3.0 and 1GiGe, you pretty-much *need* an FPGA on the 
> host-interface board
>    to do all the relevant protocol goop anyway, so perhaps making that 
> FPGA large enough

I think for USB you don't have to deal with the protocol.
USB chips will handle this, similar to the EZ-USB.