MOTOR HELP !!!!!!!!!!!!!!!!!!!

i am building a robot with the duelmilanove, and i just ordered a tamiya Tamiya 89915 Twin-Motor Gearbox Kit, i mounted on my chasis and everything seems good them BOOM i have no idea ho to connect it, do i need another shield on top of the protoshield for my PING on the bot or will it just plug right in anyways here are the motor specs

Typical operating voltage: 3 V Gear ratio options: 58:1 and 204:1 Free-run motor shaft speed @ 3V: 12300 rpm1 Free-run current @ 3V: 150 mA2 Stall current @ 3V: 2100 mA Motor shaft stall torque @ 3V: 0.5 oz·in3

dont worrry about how thick the protoshield is, the PING is soldered to header cable NOT breadboarded

The stall current is the maximum current that the motor can draw. The Arduino is not capable of providing anything like 2.1A (2100mA). Yes, you need a motor driver circuit. This is not a beginner project, so a shield is usually the easiest way to go.

but what is the motor shield i should use

Where did you get the Tamiya 89915 Twin-Motor Gearbox Kit from? Check their site. They most likely have a motor controller shield that they know works well with that kit.

Otherwise, any motor controller shield capable of supplying 2.1A will work.

I used the DF Robot one for that same situation. I was just using it to learn with and would make you a deal on it if you are interested and in the US (not worth shipping abroad). But whether you want it or get a new one, one nice thing about it is it is stackable - it has the pin headers with sockets for another card to go on top. It lets you select whether to power from the board or use external power.

what if i useda motor with these specs instead

General specifications Free-run speed @ 6V: 11500 rpm Free-run current @ 6V: 70 mA Stall current @ 6V: 800 mA

I tried it using the little motors and gearbox with both internal and external power. If it was just for rolling around a very light robot on a table top powered through the USB or a 9v, you can do it with system power. But if you use a battery pack with 6 C cells to power the Arduino, you will barely be able to move that around due to the battery weight.

Look for a motor powerful to move the weight of your robot and the batteries, that has a stall current of 40mA or less. Unless your robot only weighs a few milligrams, with batteries, you won’t find such a motor.

the motors are not connected directly to the tires tho, the are conected to the tamiya gearbox

well you could use a h bridge ic like a l298n and parallel them and use it with arduino cinnecting it with a bread board it would cost atleast 10Xlesser and is not that complicated or else look into your favourite sellers website for a motor control board with an output of 3 amps

the motors are not connected directly to the tires tho, the are conected to the tamiya gearbox

Doesn’t really matter, the arduino power regulator isnot made to power motors. You need a motor driver/controller or h-bridge setup. Check the below links.

This is the one I have:

I used it with the Tamiya gearbox/noisemaker also. I just used it to start working on functions for turning even though I will actually be using much larger motors. If you are in the US, I would send it by 1st class mail for $10 including shipping. I am too lazy to bother with eBay...

One nice thing about this board is it has jumpers that let you select system power or external and it has terminals for the external power if you decide you need it.