anchor.diff:  
       FIFO#(Bit#(32)) delay <- mkSizedFIFO(8);
       FIFO#(EchoPair) delay2 <- mkSizedFIFO(8);
  -    Reg#(Bit#(8)) ledsReg <- mkReg(0);
  +    Reg#(Bit#(LedsWidth)) ledsReg <- mkReg(0);
   
       rule heard;
           delay.deq;
  
positive.code: 
  import FIFO::*;
  import Leds::*;
  
  interface EchoIndication;
      method Action heard(Bit#(32) v);
  
negative.code:       endmethod
        
        method Action setLeds(Bit#(8) v);
  	 ledsReg <= pack(replicate(v[0]));
        endmethod
     endinterface
     interface LEDS leds;
        method Bit#(LedsWidth) leds();
           return ledsReg;
        endmethod
     endinterface
  