An LED driver circuit provides a direct input line sensing step dimming interface for controlling an LED load. The LED driver circuit includes an input voltage source, a first input line, a second input line, and a neutral line. A diode bridge is coupled to the neutral line and to each of the first line switch and to the second line switch at a side of each opposite to the input voltage source. The LED driver circuit includes a first isolation circuit and a second isolation circuit and a microcontroller having a first sense input and a second sense input. The microcontroller receives at least one of the first sense input and the second sense input from the first and second isolation circuits. The microcontroller controls LED driver circuit output to a load according to the received sense input.