Interfacing Futaba S3003 with 8051

Discussion in 'The Projects Forum' started by Fazeelayaz, Nov 28, 2013.

  1. Fazeelayaz

    Thread Starter New Member

    Nov 28, 2013
    Hi every one i have signed up just few minutes ago .I am doing my project in which I have to interface Futaba S3003 servo motor I have made programs to give pulses of 1 ms , 1.5 ms and 2 ms at 50Hz but the problem is that servo motor is not rotating as it should there is no controlling when ever pulse of any width is given at it's control pin the motor moves full left(clock wise) and locks I thought that this is due to that I am sending wrong pulse widths may be those widths are too much so tried 200us , 400us and 500us pulse widths but again same thing happened the motor always moves full 180 degrees can any one help me with this is there any problem with my Futaba S3003 any one who faced this same problem please help me with this .I am giving this code as an example that what iam doing in program this program gives 1ms pulse width after every 19 ms (total time period is 20 ms).

    ORG 00H
    CLR TF0
    CLR TR0
    MOV TMOD ,#01H ;1 ms high on P1.1
    MOV TH0 ,#0FCH
    MOV TL0 ,#21H
    SETB P1.1
    SETB TR0
    XY1: JNB TF0 ,XY1

    CLR TF0
    CLR TR0

    MOV TH0 ,#0B9H
    MOV TL0 ,#0E3H
    CLR P1.1
    SETB TR0
    XY2: JNB TF0 ,XY2 ; 19 ms low on P1.1
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    Wire a 555 as a servo tester, and make a independent test to see if the servo is ok.
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    Another servo tester: For vernior control replace R7 & R8 with a single pot of about 5k.
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    Minor nitpick; It is not a "servo motor" it is an "RC servo".

    Using the right name for the component helps others when searching the forum. :)