Help need in polulu serial comand mode

Hi !

Actualy use a SSC04A serial servo controler ,

In first used the simplest mode ,needed 3 bytes comand like > start byte , servo number ,servo position .
And have success with polulu serial transmiter software .

In second ,went use polulu mode ,and send :

the start byte > 0x80
the device ID > 0x01
the comand ,with servo , forward direction and 180° range > 0x4f
the servo number for my test number 0 like > 0x00
the servo speed in middle range like > 0x3f
the servo position ,i’m not sure but think for max forward > 0x7f

So I send this frame with polulu serial transmiter on 6 byte command : 0x80 - 0x01 - 0x4f - 0x00 - 0x3f -0x7f
to my servo controler, so red light flash,like invalid command .

But still not see where is my error ,and like use this protocol for more precision ,
For me I think start error command after servo speed cause not realy understand the set position.

Thanks for who can help me .


It seems that you are trying to put some of your data into your command byte. The command byte should have a value of between 0x00 and 0x05. Try setting the command byte to 0x02 and see if that works.


Hi Derill !

Thanks a most for your help !

It’s working good ,I understand now how protocol work ,but need yet time to work with certain parameter like speed .
I don’t understand why ,but nothing appen with this parameter …

When I set peed to very low ,servo don’t change speed and trying to now why .

But ,you help me lot Derill ,thank you very much !