Qik 2s9v1 shared motor/logic

Could you please help, I have been running a qik 2s9v1 for a while now without problems but was reviewing the user manual and found the following:

“Note: Even if your motor and logic power sources share a common ground, make sure you connect your motor power supply’s ground to the GND pin just above the VMOT pin. This ground pin is designed to handle the higher currents that your motors will draw; the ground pin above the VCC pin is not intended for high currents.”

I would like to use a single power supply for an Arduino micro, Qik logic and Qik Motor but i’m not sure I understand how to implement this.
Could you please take a look at my Frizting diagram and explain if I must change something or add some type of protection?

Note: In the picture the Qik is the badly drawn blue rectangle on the right :slight_smile:
Thanks in advance!


That looks right. The point is that all of the current going through your motor enters the qik’s VMOT pin, and then it needs to return to the power supply through a ground connection. If you only connect the GND next to VCC, that will be the return path, even though that pin is not designed to handle high currents. By connecting the GND pin next to VMOT, you are providing an appropriately high-current return path. In this setup, you actually do not need to connect the GND pin next to VCC to the ground rail since all of the qik’s grounds are internally connected, anyway.

- Ben

Thanks for the info, that helps me a lot to understand :slight_smile:
Best Regards,