This page lists some examples of analog front end designs that you might find useful. As much as possible the designs will adhere to the Scoppy ethos of keeping the price as low as possible.
Please note that these designs are definitely NOT appropriate for measuring high voltages. If you choose to use any of these designs you are doing so at your own risk. The author cannot be held responsible for any damage caused by the use of these designs.
Single-channel, single voltage-range (sensitivity) of more than 3.3V
Single-channel, single voltage-range (sensitivity) of less than 3.3V
Single-channel, single voltage range with over-voltage and under-voltage protection
Single-channel, multiple voltage ranges and over-voltage protection
Two-channels with over-voltage protection. Super cheap and easy to build. (Our recommended design)