This looks very similar to 1-Wire, which is for ultra-low power devices that communicate on and are powered by the same wire. The reason the pulse widths are di

This looks very similar to 1-Wire, which is for ultra-low power devices that communicate on and are powered by the same wire. The reason the pulse widths are different is that the falling edge of the pulse kicks off an oscillator-based timer that triggers a read of the value of the line at some point between the two durations.