In case of collecting data from external 3-channel ADC via SPI, what is the maximum possible array size in the program ? I tried for single channel and it appeared to be 127. However, when using 3-channel, high-pass filter (Butherworth, 2-nd order) and 4-stage 2nd-order IIR filter, it was reduced to about 30 samples (reduced memory size). I need at least 1500 samples, is it possible to put such amount of samples into single array for one channel ? I don't use multiple shift registers, but single shift register, through which the array is passed. I attached picture presenting simpler example.