Control system diagram of the plant lighting system and the graphical user interface. The numerals in boxes (A) in the 35 drive circuits represent peak wavelengths of the five LED types. A computer (PC) controls the operation of the 35 drive circuits for LEDs of the five types and seven modules through a data acquisition system (DAQ). The graphical user interface program (B) enables easy operation of the 35 drive circuits merely by clicking the 35 knobs with blue indicators aligned in the 5 × 7 formation in the middle to the left of the PC screen. The 35 LED current values are fed back to the PC and are displayed on the upper right tables as numerals and on the lower right black square area as line charts (B).