Powering up arduino with Xbee and a 6V (run on 5V) motor

Question

I am working on a small project where i'll need an arduino to control a motor wirelessly using Xbees.

I have a 7.4v lipo battery

I am wondering will there be a problem or insuffciency if i only use this 7.4v battery to power up the Xbee-attached Arduino and the motor (DC motor controlled by a driver board) which will be supplied with 5V getting from the arduino?

Here I relate to another problem, as I am wondering if it is because of insufficient power supply:My Xbee module is behaving kinda weird. When i try to control the motor wirelessly through signals from the Xbee, the motor isn't running until I press down on some area of the Xbee module mounted on the shield attached to the Arduino

I don't think it is merely any loose pins connection of the Xbee and Arduino or the shield, because I have tested the Xbees with LEDs, they are communicating well.

so, my question now, my 6v (run on 5v) motor is not responding well to my inputs from the Xbee-attached-Arduino, is it something to do with my power supply method?

Hope you guys could help! Thanks in advance!

Answer 1

I have a lot of bad experiences with motor noise, and I am not an expert on this subject but I guess your problem is from the noise caused by the motor (both electrical and electromagnetic noise). Just google DC motor noise and you will find tones of problems and answers on this topic.

What I would do is to try to isolate the power of the DC motor (the driver) as much as possible from the power of the Arduino (they say that in some cases, using two separate PSU's should be best, though I think not too practical). Also, you didn't mention motor specs, but be adviced that the capability of the 5V supply of the Arduino is very limited. So try double check how much current the motor draws (especially when it stalls), and how much the 5V line of the duino can supply. I don't think the 5V line is up for the job.

I would never supply a motor with the 5V of the Arduino. Also try to keep the motor physically far away from the Arduino.

When there is noise caused by the motor, all kind of funny things will happen, and unfortunately it's not very easy to tackle.

I hope some more knowledgeable ppl will provide you will more detailed advice. Dave