Get data continuously from sensors

I would *not* use a PIO if you need a constant sampling frequency. Pipe the data from the pin into a FIFO and then have the CPU pull the contents out of the FIFO or use a DMA to push it into memory. I would probably convert the data to be wider before the CPU/DMA access the data since moving 1-bit data around in a system is very inefficient. One way would be to put a shadow register between the pin and the FIFO that takes 'x' number of samples and shoves them all into the FIFO in one clock cycle. There are many other alternatives so I'll leave that to you to explore.