[patrickg_zill]

If you ran a different OS on the Pi, would you get the consistency? For instance, FreeRTOS has been ported (unsure of quality) https://github.com/jameswalmsley/RaspberryPi-FreeRTOS .

[dragontamer]

You'd get more consistency for sure, but nothing that approaches the 75MHz (13 nanoseconds!!) needed to capture data from the GPIO pins.

From my understanding of the Raspberry Pi, the GPIO pins simply weren't designed for that level of speed. Which is fine, the Raspberry Pi was designed for other stuff. Its all about tradeoffs.

[snovv_crash]

Maybe not capture, but you can write to the pins at least that quickly. I've seen projects that use the gpio of a raspberry pi to drive an FM transmitter at 100MHz.

[megous]

The project you're thinking about uses internal PLL in the SoC. This has nothing to do with GPIO reading/writing.

http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...

[snovv_crash]

Ah, my bad. I was actually thinking afterwards about how they could be doing the frequency shifts and what kind of sampling speed they would need for accurate, small frequency shift adjustments.