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Topic: Power arduino from Raspberry pi 2 (Read 3124 times) previous topic - next topic

stefanito21

Hello all,

I want to build a mobile robot using arduino mega,a raspberry pi 2 and a SN754410 quadruple high-current half-H driver. My question is , can power the arduino from the raspberry through usb? Is it enough for arduino to function properly,because all the sensors will be connected with the arduino.
The rapberry pi 2 will be powered from a Power Bank and the motor driver with a 11.2v battery.


PS: This is my first post so if i've done anything wrong, i'm sorry in advance :P  :smiley-roll:

DuaneDegn

The answer to your question probably depends on what you have connected to the Arduino.

As long as you're not pulling much current with the Arduino, you should be okay powering it from the R Pi USB port.

You don't want to power servos from USB.

CrossRoads

Connect 5V from Pi to 5V on header, Gnd to Gnd
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

DuaneDegn

Is the USB also being used for communication?

stefanito21

#4
Jan 29, 2016, 06:00 pm Last Edit: Jan 29, 2016, 06:15 pm by stefanito21
The answer to your question probably depends on what you have connected to the Arduino.
I intend to connect sensors on the arduino,wheel encoders,HC-SR04 or the lidar lite V2, and maybe a servo.

Connect 5V from Pi to 5V on header, Gnd to Gnd
Will that give more power than the usb? Also will there be a problem if i use the usb for my communication?

Is the USB also being used for communication?
Yes the usb will be also used for the communication between the arduino and the pi.

Do you have an alternative solution on how to power those three components (arduino,pi,SN754410) with less than 3 power sources? I would really appreciate if you could post any link on where to buy them.

CrossRoads

#5
Jan 29, 2016, 06:47 pm Last Edit: Jan 29, 2016, 06:49 pm by CrossRoads
Quote
Will that give more power than the usb?
There will be no limit to the power you can provide that way. Up to an amp would be ok.
Quote
Also will there be a problem if i use the usb for my communication?
That could be a problem.  You may want to remove the PTC fuse next to the USB connector so the RPi is Not attempting to power the USB in your computer if the computer voltage  happens to be low.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

stefanito21

That could be a problem.  You may want to remove the PTC fuse next to the USB connector so the RPi is Not attempting to power the USB in your computer if the computer voltage  happens to be low.
I didn't mean to connect it to my computer(sorry if i didn't explain it well). What i meant was that the arduino will be connected with the RPi through USB for communication so if i connect also the 5V from RPi to Arduino will there be a problem?

The project that i want to build will be something like this:
Robot car with an rpi for the wifi communication and a camera, the arduino for the sensors and the algorithms to move the robot car and the SN754410 to drive the motors.

MarkT

I intend to connect sensors on the arduino,wheel encoders,HC-SR04 or the lidar lite V2, and maybe a servo.
Whoa there, a servo is not a sensor!!, and its definitely not powerable from a Pi....

The Lidar Lite claims to use 100mA, HC-SR04 seems to be 15mA (though I suspect its more during a ping),
wheel encoders may be 20 to 40mA each at a guess

Servo's need separate power.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

DuaneDegn

Whoa there, a servo is not a sensor!!, and its definitely not powerable from a Pi....
Agreed.

You don't want to power the Servo from either the USB connection with the Pi or the using the header.

stefanito21

Whoa there, a servo is not a sensor!!, and its definitely not powerable from a Pi....
Yes i know what a servo is... (i am not that noob :P ) i meant the sensors plus a servo to mount either the HC-SR04 or the lidar lite.

So if i use the usb connection with the RPi i won't be enough to power the arduino with the components that i intend to use? So the only solution is to use 3 different power sources?

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