Moving at start-up even with no commad on Jetracer

Hi,

Thanks for the code. I am using a Waveshare jetracer with its schematic in driving motos and servos in this [link](https://files.waveshare.com/upload/4/4a/JetRacer_Schematic.pdf). 
Despite the settings of this hardware, the motors start spining and stop once I run the node directly. I am a bit confused since the default of this node should hold everything to 0%?
