This module can be used to test the current and voltage. The principle of voltage test based on principle of resistive voltage divider design, can make the red terminal connector input voltage to 5 times smaller. analog input voltages up to 5v, the voltage detection module input voltage not greater than 5Vx5=25V (if using 3.3V systems, input voltage not greater than 3.3Vx5=16.5V). AVR chips have 10-bit AD, so this module simulates a resolution of 0.00489V (5V/1023), so the minimum voltage of input voltage detection module is 0.00489Vx5=0.02445V. The MAX471 chip on the board used to test the consume current of the load.