Motors spins in half of all speed

Hi everyone :slight_smile:

My motors is connected to motor shield, and motor shield is mounted on arduio MEGA.

When in code I send HIGH to motors (5 volts), motors spins, but in half speed. Some months ago, motors spins really fastly, so a the robot "flyed" in my house, but now it rides really slowly, really.

Can anyone help?

syvanaLTU:
When in code I send HIGH to motors (5 volts), motors spins, but in half speed. Some months ago, motors spins really fastly, so a the robot "flyed" in my house, but now it rides really slowly, really.

If you have changed absolutely nothing since the time it was working properly it seems likely that the battery is discharged or a connection somewhere has deteriorated (perhaps corroded or worked loose).

If you have changed something (however trivial it may seem) you need to give us all the details.

...R

I don't changed anything, exept arduino (from UNO to MEGA).

syvanaLTU:
I don't changed anything, exept arduino (from UNO to MEGA).

It's time to post code and schematics....

Any chance your output control has changed from 5v to 3v3

syvanaLTU:
I don't changed anything, exept arduino (from UNO to MEGA).

I would not describe that as "don't changed anything". That is a very BIG change.

Post your code and a diagram showing how everything is connected. A photo of a clear pencil drawing will be fine.

...R

What motor shield? At 5V you'll need a MOSFET H-bridge to avoid massive losses
of the L298 and L293D's at low supply voltage.

Or is 5V only the logic supply?

More details please - ie all the relevant details so we can understand what you have there...