+ // bit cell time: 70-130us
+ // low part of bit0: 60-70% of bit cell
+ // low part of bit1: 30-40% of bit cell
+ //
+ // bit cell time 70us 130us
+ // --------------------------------------------
+ // low part of bit0 42-49 78-91
+ // high part of bit0 21-28 39-52
+ // low part of bit1 21-28 39-52
+ // high part of bit1 42-49 78-91