> perhaps 800+ is not so many?
800 is not bad, but that is spread across RPi and BeagleBone Black, I estimate nearer 450 backers were Pi owners.
This is from a total potential market of 2 million Pi's shipped, so 0.0225%? It's ok for a product like this.
I think $69 for a Spartan 6 is a great deal, I think they are planning to ship regular orders at $99 which is still ok but quite a lot compared to the basic cost of a Pi, IMHO. By contrast, you can build a Guzunty for under $20, if you want to try out HDL. While the CPLD in the Guzunty can't provide much heavy lifting for a machine vision project, it can be useful in other ways as Meltwater mentioned.
> is there something similar for the GPU?
Similar to what? The machine vision filters? Probably not, the code in the Pi GPU is closed source.
If the GPU were open source, I daresay those filters might be possible. The GPU source is closed because there are MPEG and other licensed codecs in there. Maybe the RPi Foundation could split the source and allow us to bind with a binary blob that contains the licensed code?
That would be cool. How about it RPiF?
Guzunty: A fully programmable peripheral you build yourself! https://github.com/Guzunty/Pi/wiki