Hello,
Am using a4988 arduino shield to drive stepper motors , with 12V supply , I have set VRef to 1.6V and i started running it , the problem am facing with trimmer potentiometer which is mounted on driver pcb .When i touch or press the potentiometer with any screw driver or conducting material then only the motor starts rotating .I thought there is problem with driver IC then i changed other board still facing the same .I used total 5 IC’s , facing same problem with all five driver pcb’s.
Anyone please help me regarding this.