Line tracer robot

[mister_e]

By what you provide, it will look like almost this

TRISB=%00001111


LM_FWD         var     PORTB.4
LM_REV         var     PORTB.5
RM_FWD         var     PORTB.6
RM_REV         var     PORTB.7

MaskPORTB      var     byte
PeriodHALF     var     word ' Variable for Half Speed period (pulsout)
PeriodMIN      var     word ' Variable for Min Speed period (pulsout)

' You'll have to determine value for PeriodMIN & PeriodHALF here

PORTB=0

Start:
      MaskPORTB=(PORTB>>1) & $07 ' get only B1,B2,B3 value
      Select case maskportb
             
             'LS(0) CS(1) RS (0) LM_FWD(FULL SPEED) RM_FWD (FULL)
             case 2 
                  LM_FWD =1
                  RM_FWD =1
                  
             'LS(1) CS(1) RS (0) LM_FWD(HALF SPEED) RM_FWD (FULL)
             case 3
                  pulsout LM_FWD, PeriodHALF
                  RM_FWD=1

             'LS(0) CS(1) RS (1) LM_FWD(HALF) RM_FWD (MAX)
             case 6
                  pulsout LM_FWD, PeriodHALF
                  RM_FWD=1

             'LS(0) CS(0) RS (1) LM_FWD(MAX SPEED) RM_FWD (MIN)
             case 4
                  LM_FWD = 1
                  pulsout RM_FWD,PeriodMIN
      end select
      goto start

be sure of the way you interpret your sensor... i'm not sure about the info you provide.

2. another things is how to control
if the 3 Sensor = 1 3 times cross 4 junction, the robot will stop and turn 90 deg left (for example)

you mean ?