next topic »

[on:]

Hey

I'm quite new to this whole arduino stuff, but I would like to build a small robot.
Now I have a question considering the drive. I would like it to have to seperate controllable motors that let it move.

What kind of motor should I use? I currently see three possibilities:
1. using this motorshield: http://blushingboy.net/p/motorShieldV3/
2. using the Adafruit motorshield: http://www.adafruit.com/index.php?main_page=product_info&cPath=17_21&products_id=81
3. Building my own control for the 2 motors

If I choose one of the shields, how would that work with aditional sensors? can somehow attach them to the pins on the shield and use them as normal?
Is there anything that would let me prefer one of the shield over the other?

hope somebody can help me here

greetings
vIiRuS

[Reply #1 on:]

Part of the answer will depend on what platform (and more importantly, the motors) you decide to use. Both of those shields you listed use an L293 motor driver h-bridge IC, which can only source a maximum of about 1 amp of current. This means that if you motors pull more than 1 amp, either at continuous running usage under load, or stalled (locked rotor), you'll blow the chip. So you need to figure out what platform you intend to use, and what the specs of the motors on that platform are. You might need to go with a shield or other motor controller that uses a different h-bridge configuration with more current capability.

With that said, as far as whether you can hook other sensors up will depend upon how the shield is configured. Honestly, it would be best to -not- use a shield (or at least use the shield on top of the Arduino), and instead wire the control pins from the Arduino directly to the h-bridge (whether its a shield or some other configuration). This way -you- get to pick which pins control what, and know which pins are left available for your sensors. In general, though, without performing a very detailed examination of each h-bridge shield's documentation plus your sensors, you'll have a difficult time determining what pins are being used for what, and which are free. Which is why not dealing with the shield concept, and direct-wiring stuff is a better way to proceed.

Once you know your current requirements, that is...

 

[Reply #2 on:]

I actually don't know yet which motor I'm going to use, but I think I'll try to make my own control.

Can somebody maybe recommend a H-Bridge/Motor combination that is easy to handle?

[Reply #3 on:]

Hi,

This is the one I first bought. I'ts really easy to use, can drive 2 AMPs and is low-cost.
http://www.robotshop.ca/controleur-moteur-2a-arduino-dfrobot.html

If you want to make your own motor driver/controller, you could use the L298. It is used for a lot of hobby motor driver so you won't have trouble getting help or finding lot of other designs. (what I showed you use it).

Good luck!

[Reply #4 on:]

I have designed a shield for building robots, called The Robot Builder's Shield. It allows you to control 2 DC motors (up to 1A/motor), 6 servos and read 6 sensors. You also get a prototyping area where you can optionally use a mini breadboard.

[Reply #5 on:]

I have designed a shield for building robots, called The Robot Builder's Shield. It allows you to control 2 DC motors (up to 1A/motor), 6 servos and read 6 sensors. You also get a prototyping area where you can optionally use a mini breadboard.

very cool, but your site seems to be running very slow at the moment.

[Reply #6 on:]

Hi,

This is the one I first bought. I'ts really easy to use, can drive 2 AMPs and is low-cost.
http://www.robotshop.ca/controleur-moteur-2a-arduino-dfrobot.html

If you want to make your own motor driver/controller, you could use the L298. It is used for a lot of hobby motor driver so you won't have trouble getting help or finding lot of other designs. (what I showed you use it).

Good luck!

If you decide to go with an L298 - realize that it won't fit properly onto a standard breadboard or perfboard (with 0.1 inch hole spacing). You will need to either fit it on a custom PCB or use an adaptor. I recently purchased some adaptors from this guy:

http://www.jrhackett.net/L298adapter.shtml

They are very easy to use and inexpensive. The really nice thing about them is that control inputs are on one side of the board, while the motor outputs are on the other side, which would make integrating it into a custom perfboard PCB design very easy without needing jumpers everywhere.

 

[Reply #7 on:]

If you decide to go with an L298 - realize that it won't fit properly onto a standard breadboard or perfboard (with 0.1 inch hole spacing). You will need to either fit it on a custom PCB or use an adaptor. I recently purchased some adaptors from this guy:

http://www.jrhackett.net/L298adapter.shtml

They are very easy to use and inexpensive. The really nice thing about them is that control inputs are on one side of the board, while the motor outputs are on the other side, which would make integrating it into a custom perfboard PCB design very easy without needing jumpers everywhere.

 

hmm okay. The problem is that I live in germany and therefore I wont be able to get one of the adaptors from him :/

Is there a similar controller or does somebody know a place where I could get one of those adaptors in germany?

also: what kind of motors would be advisable?

[Reply #8 on:]

it is not necessary that you uasse  a  adaptor you can just bend the pins and off you go ! thats what i do and coming to the motors you need to decide on the torque and speed you need for building a small robot a normal geared motor would serve your purpose !

[Reply #9 on:]

wouldnt there be the problem that the pins then easily could break off? or are they stable enough?

Are these motors any good? http://www.robotshop.com/eu/tamiya-twin-motor-gearbox.html

The advantage would be the interchangable gears...

[Reply #10 on:]

wouldnt there be the problem that the pins then easily could break off? or are they stable enough?

they are stable enough i've never had problems with them breaking off if the adapter is not available locally then this is the best method of doing it !

coming to the motors they could serve your purpose but again i'd ask you what is the torque you require i.e the weight the motors need to drag

[Reply #11 on:]

The tamiya twin gearbox motors are only rated for 1.5-3.0 volts.  People have run them at 5 volts, but their life can be severely shortened by doing so.  They just aren't built to handle more than 3 volts.

That being said, that gearbox is well suited to small robotic rovers.  Just don't overdrive the motors.  I burned out one of mine with about half an hour of runtime at 5 volts.  (That was half an hour of intermittent usage over a period of a few hours as I was writing and debugging my control code).

I then replaced both motors with a pair of these: http://www.robotshop.com/eu/solarbotics-regular-motor-3.html and they've been running like a champ ever since.