This page has the details of the hardware and files required for making the circuit board. Hardware has gone through two minor changes. The second version added sample and hold support for the ADC and added provisions for simultanious sampling of four channels. Number of channels reduced from eight to four. The third version have two amplifiers to convert  -5Vto5V signal to 0to5V signal. Also have all the inputs and outputs of three opamps available for user configuration.