RC with Claw/Arm combo

[rms5643]

Hello Arduino forums!

I consider myself to have intermediate experience with Ardunio. I have a project that I'm trying to accomplish and would like some guidance:

• I plan to control a simple RC car

• (something like this http://www.hobbytron.com/ChubCityLincolnNavigatorElectricRTRRCCar.html#)

• I plan to strip the body and add a claw & arm.

• The claw will be controlled by two of these (https://www.servocity.com/html/hs-5065mg_servo.html#.VjakMLerS-Z)

• The Arm will use a small micro servo that will function as a linear actuator to raise/lower the arm.

• http://www.robotshop.com/en/firgelli-technologies-pq12-actuator-20mm-100-1-6v-potentiometer.html

• The car has 2 small DC motors. I connected a AA battery one of the DC motors on the car and heard the motor move; thus can I conclude that each motor runs on ~3v? (Car has slots for 2 AA batteries)

• I plan to use a bluetooth module to control my RC remotely from my bluetooth-enabled laptop (http://www.mouser.com/ProductDetail/Adafruit/1588/?qs=GURawfaeGuCAp6XFsR2m0Q%3D%3D&gclid=CjwKEAjw8NaxBRDhiafR-uvkpywSJAAxcl6fjO0KTFsxCAOSrD6k6F7mCh3SEqykEZfC7YUSzMRlWhoCtKHw_wcB)

• I plan to use a 9V battery (maybe 2, scroll down to questions) to power the Arduino

So here are my questions:

• Since I'm looking to power 2 relatively weak DC motors, can I skimp out on grabbing the Arduino motor shield and just use a servo shield instead? I'm concerned about power if I have to stack the motor shield and servo shield. I just feel like the motor shield is overkill.

• I've seen so many guides that have DC motors connected directly to the arduino (Or to a breadboard with an RC circuit), and I've also seen so many guides that say you NEED the motor shield if you want to drive a DC motor. Can anyone clear up the ambiguity on this given my context?

Here's a super rough schematic of what I want to have done:

Can anyone shed some light on this? Maybe some suggestions/tips?

[DuaneDegn]

rms5643:
So here are my questions:

• Since I'm looking to power 2 relatively weak DC motors, can I skimp out on grabbing the Arduino motor shield and just use a servo shield instead? I'm concerned about power if I have to stack the motor shield and servo shield. I just feel like the motor shield is overkill.

• I've seen so many guides that have DC motors connected directly to the arduino (Or to a breadboard with an RC circuit), and I've also seen so many guides that say you NEED the motor shield if you want to drive a DC motor. Can anyone clear up the ambiguity on this given my context?

DC motors need some sort of motor controller. If the motor is supposed to move both directions it needs a h-bridge. Servos have h-bridge circuits inside so they can be controlled with just an I/O pin from the Arduino. A normal DC motor can NOT be powered directly from an I/O pin. You MUST use a motor controller of some type to control a DC motor with an Arduino if you don't want to burn out the microcontroller.

The servo shield will be pretty much useless for controlling a DC motor.

[rms5643]

DuaneDegn:
DC motors need some sort of motor controller. If the motor is supposed to move both directions it needs a h-bridge. Servos have h-bridge circuits inside so they can be controlled with just an I/O pin from the Arduino. A normal DC motor can NOT be powered directly from an I/O pin. You MUST use a motor controller of some type to control a DC motor with an Arduino if you don't want to burn out the microcontroller.

The servo shield will be pretty much useless for controlling a DC motor.

DuaneDegn:
DC motors need some sort of motor controller. If the motor is supposed to move both directions it needs a h-bridge. Servos have h-bridge circuits inside so they can be controlled with just an I/O pin from the Arduino. A normal DC motor can NOT be powered directly from an I/O pin. You MUST use a motor controller of some type to control a DC motor with an Arduino if you don't want to burn out the microcontroller.

The servo shield will be pretty much useless for controlling a DC motor.

Thanks for your post. Makes sense. Just picked up a motor and prototyping shields. I'll power the 6v servos with an external power supply (4 AAA or a 9V battery regulated to 6v servo input) and wire the signal wire to the IO pins of the Arduino.