Servos with Monster Moto Shield

Hi,

I need to connect 4 Servo motors (MG 995) for a project. I know that i can't connect into the 5v arduino. Can I use the Monster moto shield to control at least two of them?

I know that i can't connect into the 5v arduino.

Why not?

Each servo needs 140mA to work, I have 4 of them and they need to move simultaneously

So?
Get a 560mA power supply.
Like four AA cells.

The no-load current of an MG995 is 170mA, the stall current is 1.2A and they run best on 6V. I'd look for at least a 6V 5A power supply. 5 x rechargeable NiMH AAs might be o.k.

Of course you will connect the power directly to the servos. Only the signal wire connects to the Arduino.

And no, a motor shield will not drive servos.

Steve

Only the signal wire connects to the Arduino.

Bzzzt. Wrong.

The ground wire needs to be connected, too.

Or all servo ground wires need to be commoned with the power supply and Arduino grounds.

Amazing how often one forgets to state what should be obvious innit?

Steve

slipstick:
Amazing how often one forgets to state what should be obvious innit?

Why should it be obvious to a beginner though? (Not that OP is necessarily one.) Sure, once you say something like "well you can't measure the voltage of a battery with only the red lead..." the penny drops, but the notion of needing a 0 for the Arduino to measure the signal against is not that obvious to all.

Indeed. It was me I was criticising there. When you've known something for 50-odd years it starts to seem obvious, common knowledge even.

Perhaps you never have this problem but I certainly find that I sometimes forget to mention things of that nature. Must try harder.

Anyway I hope the OP has the main point...the red +ve wire from the servos should go direct to the power supply not to the Arduino.

Steve

slipstick:
Indeed. It was me I was criticising there.

Ah right- sorry