There are two rotary switches of three positions on the motherboard (item 4 of Figure 2) to modify the ADC input range for each Beetle chip. The position 2 corresponds to an input range of ± 512 mV (with a resolution of 1 mV). The position 3 corresponds to an input range of 1024 mV (with a resolution of 1 mV) only for positive signals. The position 1 corresponds to a input range of -1024 mV (with a resolution of 1 mV) only for negative signals.