hi
i want to run a robot and because arduino is on the robot i can use sub or adapter for power supply and i see 2 different connections for power of arduino in the internet
The first setup doesn't work at all. It has never worked. Using a PP3 battery.
The second will hardly work using the old voltage waisting L298. Change to a MOSFET based driver.
The first wiring is bad. It shows a wire from driver +5 to UNO Vin. Completly wrong.
If the driver board produces 5 volt it should be connected to UNO 5 Volt pin.
The second drawing can work with 6 * 1.5 volt batteries.