You will need external analog multiplexers like the ADG1606 here:ADG1606 Datasheet and Product Info | Analog Devices
Four of these hooked up to analog input pins, and a few digital output pins for control and you can read 64 voltages.
You will need external analog multiplexers like the ADG1606 here:ADG1606 Datasheet and Product Info | Analog Devices
Four of these hooked up to analog input pins, and a few digital output pins for control and you can read 64 voltages.