analog_preprocessing.m

function [result] = analog_preprocessing(analog_signal,parameter,downsample_rate,medianfilt)

    % parameter (acquisition): [sampling frequency, sampling resolution, sampling range]
    
    disp(['analog_preprocessing started, downsample to 1/',num2str(downsample_rate),' medianfilter with ',num2str(medianfilt)])
    analog_freq = parameter(1); % unit: Hz
    analog_pixeldepth = parameter(2); % unit: bit
    analog_inputrange = parameter(3); % unit: V
    
    % Ball signal
    downsample_signal = downsample(analog_signal,downsample_rate);
    downsample_freq = analog_freq/downsample_rate;
    medfilt_analog = medfilt1(downsample_signal,medianfilt);
    
    % scale
    rescale_signal = medfilt_analog*analog_inputrange/2^analog_pixeldepth;
    
    % xaxis
    downsample_duration = length(downsample_signal)/downsample_freq;
    downsample_xaxis = linspace(0,downsample_duration,length(downsample_signal));
    result = cat(1,downsample_xaxis,rescale_signal);

end