How to connect two Motor Drivers 18V15A to Arduino board?

Hello

I like to control two 12V DC Gear Motor with two Pololu 18V15 A motor drivers (https://www.pololu.com/product/755) and Arduino Uno micocontroler. So my concern is do I need two AC power supply adapters and how to connect them to Arduino Uno board.
So the left side of the Driver I will connect like these. Driver1 : GND goes to GND of the power Supply 1 and to Arduino . OUTA and B to Motor 1, and V+ to 12 V of the Power Supply1.
Right Side of the Driver 1: Ground Goes to Arduino, Dir and PWM go to digital pins of Arduino

Driver 2 : GND goes to GND of the power Supply 2 and to Arduino . OUTA and B to Motor 2, and V+ to 12 V of the Power Supply2.
Right Side of the Driver 2: Ground Goes to Arduino, Dir and PWM go to digital pins of Arduino

Problem is I dont have enough GND and Vin pins in Arduino board to connect two Motor Drivers and two Power Supply. Any help?

Thanks

Hello.

It is hard to follow all of your connections from your description. For example, I do not see any connection to VIN mentioned, but it sounds like you are concerned about not having enough connection points for it. It sounds like you are connecting to the GND pin on both sides of the driver. Please note that the GND connections on the High-Power Motor Driver 18v15 are connected internally on the board. Similarly, the connections labeled V+ are also connected on the board, and to power the driver, you should use the V+ and GND connections that are in-line with the OUTA and OUTB pins.

You should be able to connect a power supply to each of the motor drivers through the V+ and GND pins I described, then make a connection between the GND pin on the other side of the driver and the Arduino. This way, the ground connections from both supplies are running to the Arduino’s ground, which should only use two of the three GND pins available on the main headers of the Arduino.

If you still do not have enough ground connections on the Arduino, you could use something like a separate ground bus to connect all of your grounds together.

If you post a diagram of your connections, I would be happy to look it over for you.

-Brandon

The 5V pin from Power Supply is connected to Vin of Arduino. But When I have two motors and two power supplies I dont know where goes the 5V of the second power Supply,. I inculcated the diagram with two motors .When I have only one motor and one power supply is works perfectly
Tw_motors.pdf (560 KB)

this is the diagram with one motor and works perfectly
One_Motor.pdf (359 KB)

The Arduino Uno has a recommended input voltage of 7-12V, so you should not be trying to power it with 5V on the VIN pin. You should be able to leave the 5V line on each of your power supplies disconnected and power the Arduino from one of the 12V lines. To do this, you can run a wire from the V+ terminal block on one of your motor drivers to the Arduino’s VIN pin. I did not notice anything else wrong with the power connections shown in your two motor diagram.

-Brandon