Using arduino & LM324N & current-voltage transformer to safely collect hurge AC current
Current transformer: 50V/1V rms
Chinese make MAX7219 4-in-one Matrix display
Max7219 - VCC - 5V
Max7219 - GND - GND
Max7219 - DIN - MOSI (11)
Max7219 - CLK - SCK (13)
Max7219 - CS - 10
LM324N - Out1 - A1