So far from what ive gathered the 20 bits each bit Is clocked in by a low to high transition of the clock pin and a low to high transition of the strobe pin sends the data to the output pins so say if I want the output pins 1 and 4 high and the rest low I'd make data 1 then clock 1 data 0 clock 1 data 0 clock 1 data 1 clock 1 and data 0 for the rest of the bits then make strobe 1 to set the outputs