A system for assaying electronic or electrochemically active materials or devices made therefrom includes a microcontroller, a main digital-to-analog converter (DAC), current and voltage sensing modules, a reference voltage DAC, and a power switch. The reference voltage DAC applies a calibrated voltage across the materials/devices, and the switch disconnects the main DAC to generate an open-circuit voltage. The microcontroller assays the materials/devices using the measured voltage, measured current, reference voltage, and/or open-circuit voltage. The main DAC may include coarse and fine DACs. A method of assaying the materials/devices includes measuring an electrical current in and a voltage across the materials/devices using the respective current and voltage sensing modules, applying a reference voltage across the materials/devices using the reference voltage DAC, activating the switch to disconnect the DAC to generate the open-circuit voltage across the materials, and using the microcontroller to assay the materials/devices as noted above.