I am working on a project where due to weight limitation I cannot use multiple battery sources for my Arduino Mega and my brush lees motor model no AC 2836-385. I want to use an LiPo battery whose ratings are 3S 11.1V 2500 mAh 25C. Since the motor requires High current I plan to use an ESC with it and provide PWM using my Arduino. The problem I face is how to use the LiPo battery to power both the Arduino and the motor. My main concerns are as follows:
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I know I need to connect both the Arduino and the motor in parallel with each other but should I use voltage regulators in order to provide a constant voltage to the ESC. The Arduino should not have a problem since its optimal range is 7-12 V?
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As the motor and Arduino consume power from the battery will the ESC act as voltage regulator and make sure that voltage across the motor remains constant or do I need voltage regulators over there as well?
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Another approach that I am thinking about is to use the BEC on the ESC to power the Arduino is this a good approach?
I would highly appreciate any input on this problem and if required can provide more information on the components as well.
Link for motor specification:
http://store.jdrones.com/AC2836_358_Motors_p/ac2836358.htm
danial_ameen:
- I know I need to connect both the Arduino and the motor in parallel with each other but should I use voltage regulators in order to provide a constant voltage to the ESC. The Arduino should not have a problem since its optimal range is 7-12 V?
This is one option. Motors can cause noise on the power line but the Arduino's regulator would likely limit the noise.
danial_ameen:
2) As the motor and Arduino consume power from the battery will the ESC act as voltage regulator and make sure that voltage across the motor remains constant or do I need voltage regulators over there as well?
You don't need to worry about the ESC's voltage. In general you want the ESC connected directly to the battery without a regulator in between the two.
danial_ameen:
3) Another approach that I am thinking about is to use the BEC on the ESC to power the Arduino is this a good approach?
I think this is likely the most common approach people take when using an ESC with an Arduino. At least this is very common when the Arduino is controlling something like a quadcopter.
I personally think powering the Arduino with the BEC is your best option.
Connect the 5V from the BEC to the 5V line on the Arduino.
Really appreciate your input, however I am still not convinced on the 2nd one does the ESC have an internal regulator which makes sure that the motor receives a constant voltage or not. I need to convince one of my partners in the project and I need to be 100% sure before I suggest any changes.
If you are convinced, why ask if you are going to ignore advice that doesn't match with your plans?
Go ahead and try option 2. You will waste a bunch of battery power because the BEC will be active anyway and you'll be burning useless electrons with the regulator.
Or,,,
Go ahead and use the BEC to power the Arduino. That's what it's there for and it is regulated. one of the design features of good ESC's is to shut down the motors BEFORE you kill the battery and still allow the lower power peripherals (receiver, servos, control logic) to work in an emergency mode ( to aid in saving the craft from a crash).
danial_ameen:
Really appreciate your input, however I am still not convinced on the 2nd one does the ESC have an internal regulator which makes sure that the motor receives a constant voltage or not. I need to convince one of my partners in the project and I need to be 100% sure before I suggest any changes.
You're going to try to regulate the power to the ESC?
The ESC is designed to be used with a battery. You're asking for trouble if you add a regulator.
Really YOU DO NOT NEED A REGULATOR BETWEEN THE BATTERY AND ESC. It's a very bad idea.
A lot of people use these sorts of motors and ESCs.
I personally don't use the ESC to shut down power to the motors. I use a LiPo alarm. I'd rather kill my battery pack than let the ESCs decide when to start lowering power levels. They aren't likely to all lower power at the same time with a quadcopter.
123Splat:
If you are convinced, why ask if you are going to ignore advice that doesn't match with your plans?
Go ahead and try option 2. You will waste a bunch of battery power because the BEC will be active anyway and you'll be burning useless electrons with the regulator.
Or,,,
Go ahead and use the BEC to power the Arduino. That's what it's there for and it is regulated. one of the design features of good ESC's is to shut down the motors BEFORE you kill the battery and still allow the lower power peripherals (receiver, servos, control logic) to work in an emergency mode ( to aid in saving the craft from a crash).
Thanks I now have a better idea and I am going to power my Arduino using the BEC as things have become much more clearer thanks to you.
123Splat:
You will waste a bunch of battery power because the BEC will be active anyway and you'll be burning useless electrons with the regulator.
I'm not sure what you mean by this. Most of the BECs I've seen (which are part of an ESC) use linear regulators for the 5V output. These will be consuming very little (if any) power when not used.
I certainly agree using the BEC on the ESC to power the Arduino is good idea, but it's very common for BECs to remain unused.
Duane,
If you already have a regulator in circuit (the BEC), then adding another is just wasting parts and (albeit very little) power. If what you want is a regulated drop in voltage, why not use what is already provided?
As to motor cut off, depends upon the vehicle (or application). winged, you at least have a chance of controlled glide to landing; heli, maybe you can manage a controlled auto-rotate; quad or hexie, you're right. No motor power, go boom boom. I also use a lipo warning on all vehicles, but with the motor cutout on winged vehicles.
123Splat:
Duane,
If you already have a regulator in circuit (the BEC), then adding another is just wasting parts and (albeit very little) power. If what you want is a regulated drop in voltage, why not use what is already provided?
As to motor cut off, depends upon the vehicle (or application). winged, you at least have a chance of controlled glide to landing; heli, maybe you can manage a controlled auto-rotate; quad or hexie, you're right. No motor power, go boom boom. I also use a lipo warning on all vehicles, but with the motor cutout on winged vehicles.
Thanks for clarifying. I'll just add my agreement to the above.
I also think the power cutoff feature is a good idea on winged vehicles. It's pretty easy to fly a winged aircraft out of an alarms audible range.