I am on thin ice here, but I
I am on thin ice here, but I am pretty sure the 330 ohm is only because the servo (depending on make) can generate quite much electrical noise. What this could mean is that the chips controlling it would get a little disturbed, perhaps resetting or acting iradical… But no smoke 
It is not the chip that is powering the thing, so there should not be any worries… unless crazy behavior from the chip seams frightening.
/ Fritsl
Awesome, Thank you! Nice
Awesome, Thank you! Nice walker you’ve got going on there. I havn’t decided what to build yet.
The resistor will not
The resistor will not protect you from noise. You would need a capacitor for that, but the resistor will limit the current. Also, the noise is on the supply lines, not the control lines.
Btw: Check this out for info on servos: http://www.princeton.edu/~mae412/TEXT/NTRAK2002/292-302.pdf
well after a good half an
well after a good half an hour reading all his and followning links i have decided the i need one of those polou motor controller thingos and a few servos to make my new brain bubble robot ( idea ) the …( drum roll please.)
TANKDOSER ROVER 1.0 !!! OMG! AH ITS COMMING! GET OUT IT WILL CRUSH OUR TOES! AHHHH!
it will be prety neat combining all ideas from like ever into a single robot. im exited. ( not really cos its 10 pm)… bed time.
AVR microcontroller boards with integrated motor drivers
As an FYI, Pololu sells a line of Orangutan robot controllers that feature ATmega168s AVRs (the same microcontrollers that Arduino boards have) along with additional hardware such as built-in dual motor drivers, which can greatly simplify the electronics side of your robot. While not officially Arduinos, they can be programmed with Arduino library code from the Arduino IDE (after some minor reconfiguring) using an AVR ISP programmer, or you can just use WinAVR with AVR Studio.
They’re not intended for beginners, but they’re great if you’re familiar with AVRs or if you’re looking to upgrade from something like a Basic Stamp to a higher-performance microcontroller.
- Ben
I just bought and arduino
I just bought and arduino because all i own in my house are macs, and i wanted to mod out a car for my first project. All i need to do it make it control a motor backwards and forwards so i was thinking about this relay because is able to be done on 40 mA and thats what a arduino i/o pin can source http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=842953 is there any reason this relay wouldn’t work for driving a motor with out a transistor or anything. It is DPDT so it will be able to back and forward on the car from one i/o line. So please tell me if this wouldn’t work before i go wast three dollars on some relay that will never work. Oh and this relay should be able to hand the motor in the car its only 12 v and like 500 milliamperes
Edit. I Would add another transistor 2n3904 between the battery for the motor and the line going in to kill the power to the motor when it wasn’t in use. this would be connected to another I/O line. i think this is probably the best solution for me because i am able to control one motor with two i/o lines stop reverse and forwards . So if i were to use a hbridge i would have 8 lines for 2 motors to do the same i could do with about 4, not with all the functions with most of the basics ones though.
Dan, this just cleared up a
Dan, this just cleared up a lot of questions I had. Thanks.
I’m glad it continues to
I’m glad it continues to help people
Dan
diode
Dan,
Wouldn’t a diode be needed for the 2N3904 method to protect the arduino, I have seen this on other sites where they put it in parallel with the 2N3904 but some sites have said to put in in parallel with the motor, which of these will give the best results.
Also i was thinking of using an RC car as a base for my first robot, I am presuming it would have a motor controller built in, what are the chances of salvaging this for reuse with the arduino.
