I'm new here, so excuse my basic question. I have Arduino uno, 2x 12V motors and H-bridge L298N and I want to power that without connecting via USB, so only with battery package. And I also want to power that using only one battery package. I am not sure how to do that, becase arduino needs 5V (and can handle up to 9V, is that correct?) and the H-bridge needs more to operate. I am even not sure how many volts do I need to power the H-bridge to be able to operate two 12V motors. Can anyone help me, how to power Arduino UNO and the H-bridge from single battery pack? And how many Volt do I need for the H-bridge?
knut_ny:
Common GND to arduino and shield. 12V to shield Ucc imput and the Vin pin (or barrel cgack) on your UNO
..some shields have a Voltage_out option.
I'd also try our friend google > "arduino uno l298n dc motor" (images)
I have read several articles on google and found exactly what I need. There it is:
The problem I have is that I dont understand what is the intersection on the wires going from the battery pack. The intersection divide the positive and negative wire to two branches, one going to the L298N and one to arduino. I am not sure, how to construct that in practice. Can you give me an idea?
May I suggest that you find a more modern motor driver? The L298 is ancient and inefficient technology. It wastes power in the output stage by dropping 2 to over 4 Volts. That is your battery power going up as heat and not reaching your motor. Pololu has a good line of motor drivers and very good instructional pages on the use of each of their products.
Also pick up a DC DC converter to drop the motor supply battery voltage to 5V to the Uno. Resist the temptaion to use the Vin or power jack to power the Uno. Powering through Vin or the power jack means that the Arduino and all peripherals that are on the 5V rail are powered by the onboard 5V regulator. The on board 5V regulator is not heat sinked so will supply limited current before it overheats and shuts down. The recommend max power dissipation for the regulator is 1 Watt. With 12V into the regulator the max current is about 140 mA (1W / (12V - 5V)). The Arduino uses around 50ma of that leaving less than 90mA (max) for everything else. I would use a buck converter to drop the 12V to 5V and connect that to the 5V on the Arduino, bypassing the, weak, 5V regulator.
groundFungus:
May I suggest that you find a more modern motor driver? The L298 is ancient and inefficient technology. It wastes power in the output stage by dropping 2 to over 4 Volts. That is your battery power going up as heat and not reaching your motor. Pololu has a good line of motor drivers and very good instructional pages on the use of each of their products.
Also pick up a DC DC converter to drop the motor supply battery voltage to 5V to the Uno. Resist the temptaion to use the Vin or power jack to power the Uno. Powering through Vin or the power jack means that the Arduino and all peripherals that are on the 5V rail are powered by the onboard 5V regulator. The on board 5V regulator is not heat sinked so will supply limited current before it overheats and shuts down. The recommend max power dissipation for the regulator is 1 Watt. With 12V into the regulator the max current is about 140 mA (1W / (12V - 5V)). The Arduino uses around 50ma of that leaving less than 90mA (max) for everything else. I would use a buck converter to drop the 12V to 5V and connect that to the 5V on the Arduino, bypassing the, weak, 5V regulator.
Thank you for your advice,
I will definitely go with the DC DC step-down converter, that is great idea, also because I need the arduino board to power other 5V peripherals, such as the ultrasonic sensor. On the other hand I will probably stick with the inefficient L298 motor driver, because I already have one at home. Now I consider how big battery pack should I use to be sure that the motors and arduino (with peripherals) are working properly. I would be glad for any information!
Thank you very much! I'm happy to see an option without having to add the heat shrink. If it's feasible I am going to attach more wires anstead of soldering the Ts and adding the heat shrink.
thnaks
To, intelligently, pick a battery you need to know the average current draw of your circuit. Knowing that and the amount of time between battery changes/charges you will know the capacity (Amp Hours) that you will need.
