My arduino car project.

Hey, usually motors take just what they need, if you supply them with the right voltage, so you probably need a voltage regulator and a brown out detector so you cut the current when the voltage is below the minimum threshold.

You should worry about what happens when they get stuck, in which case they'll start drawing as much current as the wire resistance allows it. You don't want to limit the current flow, but actually completely cut it, or cut it for a while and then reverse it (in an attempt to get unstuck). Since lower current won't get it unstuck and maintaining power while stuck, can fry it, you need a way to detect over current and act on it fast.

To detect over current you can use a comparator (some AVRs have one or two on board) and feed the output to the MCU, it should be able to handle it fast enough before any damage is done to the motor, but extra care must be taken so you make sure the code doesn't get interrupted for too long or that it gets run with too much of a delay. Once the AVR is notified, it can either cut current to the motor or it can go trough some movement pattern to unstuck it and if that fails it eventually gives up and cuts the current.

As an extra precaution, you can use the humble fuse, a slow blow fuse with the appropriate current rating should do the job and protect at least the motor and the batteries from getting fried.

I hope this answered your question.

Edit: I don't know what kind of motors and solar panels you have, but generally speaking you need a fairly big panel to drive even a low power motor. Solar panels are normally used to recharge a rechargeable battery, rather than to drive a heavy load directly.

Razvan

Hey, usually motors take just what they need, if you supply them with the right voltage, so you probably need a voltage regulator and a brown out detector so you cut the current when the voltage is below the minimum threshold.

You should worry about what happens when they get stuck, in which case they'll start drawing as much current as the wire resistance allows it. You don't want to limit the current flow, but actually completely cut it, or cut it for a while and then reverse it (in an attempt to get unstuck). Since lower current won't get it unstuck and maintaining power while stuck, can fry it, you need a way to detect over current and act on it fast.

To detect over current you can use a comparator (some AVRs have one or two on board) and feed the output to the MCU, it should be able to handle it fast enough before any damage is done to the motor, but extra care must be taken so you make sure the code doesn't get interrupted for too long or that it gets run with too much of a delay. Once the AVR is notified, it can either cut current to the motor or it can go trough some movement pattern to unstuck it and if that fails it eventually gives up and cuts the current.

As an extra precaution, you can use the humble fuse, a slow blow fuse with the appropriate current rating should do the job and protect at least the motor and the batteries from getting fried.

I hope this answered your question.

Edit: I don't know what kind of motors and solar panels you have, but generally speaking you need a fairly big panel to drive even a low power motor. Solar panels are normally used to recharge a rechargeable battery, rather than to drive a heavy load directly.

Razvan