Ken,
I do not know anything about RC stuff, but here is something to play with.
Code:
<font color="#000080"><i>'16F887 INT RUPT
'44 PIN DEMO BOARD
   </i></font>@ <font color="#0000FF"><b>__config _CONFIG1</b></font>, <font color="#0000FF"><b>_INTRC_OSC_NOCLKOUT </b></font>&amp; <font color="#0000FF"><b>_WDT_ON </b></font>&amp; <font color="#0000FF"><b>_MCLRE_OFF </b></font>&amp; <font color="#0000FF"><b>_LVP_OFF </b></font>&amp; <font color="#0000FF"><b>_CP_OFF
   INTCON</b></font>.<font color="#800000"><b>5 </b></font>= <font color="#800000"><b>1    </b></font><font color="#000080"><i>'ENABLE TMR0  DATA SHEET SECTION 14.3.2
   </i></font><font color="#0000FF"><b>OSCCON </b></font>= <font color="#800000"><b>%01110000 </b></font><font color="#000080"><i>'8 Mhz
   </i></font><font color="#0000FF"><b>OPTION_REG </b></font>= <font color="#800000"><b>%10000111  </b></font><font color="#000080"><i>' 1:256 PRESCALE
   </i></font><font color="#FF0000"><b>ON INTERRUPT GOTO </b></font><font color="#0000FF"><b>TLOOP
   CNT  </b></font><font color="#FF0000"><b>VAR BYTE
   </b></font><font color="#0000FF"><b>D    </b></font><font color="#FF0000"><b>VAR BYTE
   </b></font><font color="#0000FF"><b>D </b></font>= <font color="#800000"><b>0
   
   </b></font><font color="#0000FF"><b>START</b></font>:
   <font color="#FF0000"><b>FOR </b></font><font color="#0000FF"><b>CNT </b></font>= <font color="#800000"><b>0 </b></font><font color="#FF0000"><b>TO </b></font><font color="#800000"><b>150
   </b></font><font color="#FF0000"><b>PWM </b></font><font color="#0000FF"><b>PORTD</b></font>.<font color="#800000"><b>7</b></font>,<font color="#0000FF"><b>D</b></font>,<font color="#800000"><b>100
   </b></font><font color="#0000FF"><b>D </b></font>= <font color="#0000FF"><b>D </b></font>+ <font color="#800000"><b>2
   </b></font><font color="#FF0000"><b>NEXT </b></font><font color="#0000FF"><b>CNT
   </b></font><font color="#FF0000"><b>GOTO </b></font><font color="#0000FF"><b>START
   
   </b></font><font color="#FF0000"><b>DISABLE
   </b></font><font color="#0000FF"><b>TLOOP</b></font>:
   <font color="#0000FF"><b>INTCON</b></font>.<font color="#800000"><b>2</b></font>=<font color="#800000"><b>0 </b></font><font color="#000080"><i>' DATA SHEET SECTION 14.3.2
   </i></font><font color="#FF0000"><b>TOGGLE </b></font><font color="#0000FF"><b>PORTD</b></font>.<font color="#800000"><b>4
   </b></font><font color="#FF0000"><b>RESUME
   ENABLE
</b></font>