How do I connect 2 brushless motors and a servo to arduino w/ 2200 mAh 3s LiPo?

So as the title says I am trying to have a 2200 mAh 3s LiPo battery power 2 brushless motors w/ ESC's, a servo, and an Arduino with usb shield. I will be using usb dongles to be able to control this with a PS3 controller.

Should I use another battery pack to power the Arduino which will power the servo? Or should I use the LiPo and step down the voltage through the breadboard?

Is my diagram correct? Please list what supplies I will need, if I need a breadboard or XT60 connectors, etc. Please list these.

Thank you I appreciate the help! I will keep you updated as I make progress with my project over the course of the next 2-3 weeks!

Do the ESCs have a BEC (battery elimination circuit (aka voltage regulator))? If so, how much current can they supply?

Can your Arduino be safely powered with 12.6V from your freshly charged LiPo pack? (I don’t know the max voltage allowed.)

What kind/size of servo are you using? It may not be a good idea to power it from the Arduino’s 5V regulator if that’s what you’re doing.

How are the ESCs being connected to the Arduino? Where does the middle (red) wire connect?

If you need/want to power the Arduino and shield from the ESCs’ BECs, then you’ll need to know how much current you will need to draw from the BECs and to know if the BECs can handle it or not.

AztecEngineer: Hey Duane I really appreciate the reply, the ESC's do have BEC's built in (see photo- they do right?).

Yes, the ESCs do include BECs. This can be very helpful.

AztecEngineer: I am connecting the ESC's in parallel so that they will each be supplied 1.1A (2200mAh battery)

The amount of current the battery can safely provide will depend on the C rating of the battery. If the battery has a XT60 connector, it's likely made for RC vehicles so the C rating is probably at least 10. More likely, the C rating will be 20 since this seems to be a common rating for LiPo packs used in RC vehicles. The C rating should be listed on the battery.

If the battery has a C rating of 20 it will be able to provide up to 44A (20 * 2.2A). So each motor could draw 22A each. This assumes the C rating is 20. You'll need to adjust these figures if your battery isn't 20C.

AztecEngineer: The BEC's can supply 5V/2A and the ESCs are capable of taking 30A and DC between 5V-12.6V.

I assume you want to power the Arduino and servo from the LiPo pack? 12.6V is kind of high for an Arduino to use on its Vin. I'm pretty sure it's safe to bypass the regulator on the Arduino and provide power directly to the 5V line. I suggest using one BEC to power the Arduino and shield, and the other BEC to power the servo. The ground lines of all these devices will need to be connected together.

AztecEngineer: I am pretty sure to only connect one(or none see below) BEC to the Arduino otherwise it will fry... Im I correct?

It's generally a good idea not to use voltage regulators (aka BEC) in parallel. If one regulator provides a little higher voltage on the output, it will end up having to supply all the current. I'm pretty sure attempting to use regulators in parallel has caused me trouble in the past. I avoid using regulators in parallel when possible. (Interestingly when I removed the shrink wrap from one of my ESCs, I found the BEC used two regulators in parallel. So apparently it's possible to use them this way.)

AztecEngineer: Or should only the signal wire be sent to the Arduino? Especially because the Voltage will be to great for the arduino and it wont be able to step down to a manageable voltage.

You do need to be careful about what wires you connect where but it sounds like you're on the right track.

AztecEngineer: Ok well previously to me receiving help from you I already ordered the external battery pack that will hold 6 double A's and will plug into the Arduino.

I generally don't use a second battery pack for my controllers but using a second pack is a common practice. It often makes troubleshooting easier to use a second pack.

AztecEngineer: I just need to connect the signal wires from the ESC's into the Arduino.

AND the ground line. Very important.

AztecEngineer: The battery is 11.1V and has a 20C (is this coulombs or is it another rating?)

I know it's not coulombs but I don't know if it's an abbreviation of a word. It's just and agreed term to designate how much current the battery can source. Hobby LiPo packs are generally charged at 1C. Batteries for consumer electronics are generally charged at 0.5C (though this shouldn't be considered standard).

AztecEngineer: 44A sounds like a lot of current for the Arduino and so does 11.1V so I am thinking the external battery pack is the way to go. Let me know your thoughts.

The current the battery can supply doesn't effect the device pulling power from the battery. You could use a battery for an electric forklift with the Arduino as long as it was the correct voltage. You can't be too rich or have too much charge capacity.

AztecEngineer: However, I would like to power the Servo from the lipo. However, I think it will be much easier having it powered through the Arduino and the 6 AA batteries.

This would likely be a problem unless the servo can use the raw battery voltage. To power the servo from the AA pack, you'd probably want to use the 5V from the Arduino's regulator. This would probably be okay if the servo is a small 9g servo but a full size servo would likely cause problems for the Arduino if it's powered from the Arduino's 5V line (there are several reason why this would likely be a problem). I think you'd be better off powering the servo from a BEC.

AztecEngineer: This is for a PS3 Controlled hovercraft by the way =).

Very, very cool!

You ought to think about joining We'd love to see pictures of your hovercraft and you could get additional advice about what parts to use with your hovercraft.