But bear in mind this is limited to a single channel at a maximum data rate of around 200kHz
am I correct that on an 16mhz avr, this unrolled code takes an st (2 clockcycli) and in (1 clockcycle) instruction, meaning a sample rate of 16/(2+1) Mhz ? and therefore covering less than a millisecond in a 1024 byte buffer ?
One beginners question : is there a read operation which reads a whole port (8 pins) in sketch ? ReadByte() or something ? it is imperative I read all 8 (or 4) bits at the exact same time.
And one more thought: it is only reasonable if you have way more time than money. As already mentioned you can get much better ones for little money.