I have two (well, I have ordered) 9v motors. I think they are same as motors from toys. So, is it enough 5v from PWM of atmega16?
You really can’t run
You really can’t run motors directly from your digital out PWM. You need some sort of transistor setup that can handle the current. With a simple transistor setup you can only drive your motor one direction, if you add an H-bridge motor driver then you are free to go forward and backward.
And it’s never a good idea to run the digital circuits on the same power supply as the motors.
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As to whether your motors
As to whether your motors will work at 5V or not, we cannot possibly know that for sure. We have no idea what motors you ordered. Small DC motors will work at a range of voltages. They’ll go faster at higher voltages, and will pull higher current through them at those higher voltages. Too low and they won’t want to turn at all. Too high and you can damage them.
You are probably safe to try them at 5V from a battery. As Geir pointed out, don’t try to run them directly from the output of your microprocessor, you can damage the processor when the motor tries to pull more current than the processor can supply.
Do the motors you ordered have gears attached or do you intend to connect them to a gear train of some sort? Ungeared DC motors spin way too fast and with very little torque for most robotics applications.
Can I then use power fet or
Can I then use power fet or maybe transistor 2N3904?
Yes, you can use an external
Yes, you can use an external FET or BJT transistor to provide power for your motor. However, a single transistor will only allow you to turn your motor in one direction. If you need bi-directional control for both motors, you need something called an h-bridge. There are ICs available that include two h-bridges (one for each motor), or you can build your own.
It might help if you explain what you are trying to do with your motors.
Well. For now simple
Well. For now simple movement is enough. Turning with only one motor and going forward with both motors. But later I will maybe need some complex movements. Do you have some H-bridge tutorials (building my own, not using IC)?
If your frailly new to this
If your frailly new to this type of work, you would probably get it up and running faster using a H-bridge rather than building your own. When you have gained some more experience you could build your own H-bridge… but your probably won’t.
I’m good with AVRs and
I’m good with AVRs and electronics, but never before trued myself with robots. Thank you for all information.
Try searching this site for
Try searching this site for h-bridge matrix and you will find a good tutorial.
Is TA7354P H-bridge driver?
Is TA7354P H-bridge driver? Sry for bothering.
Yes. Check the datasheet
Yes. Check the datasheet (google is your friend): http://www.datasheetcatalog.org/datasheet/toshiba/4026.pdf
This particular h-bridge is designed for a supply voltage of 6-15V DC. So you will likely need a separate power source for your processor and your motors.
The output current is only 200mA average and 600mA peek. Make sure your motor is within those specifications.
This is a single h-bridge, so you will need two of them if you want to drive two motors.
If you already have this part or can get it easy/fast/cheap and your application meets the criteria above, then it should be OK. Note the recommended use of a diodes in Application Notes figure 4.