DougieLawson wrote:I can't see it being a substitute for the PiCamera. It's an ideal camera for things like Arduinos that don't have a GPU.
The interface for the pixy is serial (or USB) so you instantly lose the PiCamera's direct connection to the GPU and at the same sort of price as a PiCamera the choice of which one to use with a Raspberry Pi is a "no-brainer" (as our American cousins would say).
That's technically accurate, but the point of the Pixy is that it has on board processing, so in a sense it has it's own 'GPU'.
Pixy addresses these problems by pairing a powerful dedicated processor with the image sensor. Pixy processes images from the image sensor and only sends the useful information (e.g. purple dinosaur detected at x=54, y=103) to your microcontroller. And it does this at frame rate (50 Hz).
It's a vision sensor rather than a camera. If you want images use a camera, if you want to sense things using vision a Pixy might be a good option.
I think Pi could probably match the 640 x 480 colour blob detection at 50 frames per second that Pixy claims.
Watch out for latency.
Pi possibly has a faster processor - 700+MHz Arm6 + VC4 GPU vs NXP LPC4330, 204 MHz, dual core.
Pixy come ready to go as a vision sensor, and is programmable. You have a bit more work to do on Pi.
Pixy has better interfaces for use as a microcontroller peripheral (Pi doesn't support i2c or SPI slave/device modes.
Given the prices - £50 Pixy (PiHut) vs Pi A + PiCam £30 I think Pi has a clear edge as a general purpose vision sensor. If Pixy does enough for your application out of the box it's worth considering..