hey i am using p89v51rd2 8051 microcontroller in robo application i connected port3.0 pin of controoler to l293d chip of pin 2 ,and port3.1 pin of controller to l293d chip of pin 7; port3.0=1 port3.1=0 but at port3.1 voltage is fluctuting from 4 to 2 volt i am facing this problem from last few days plzz suggest me some solution