Motor driver design

I am finally out of school (BSEE), and didn’t learn shit there.

Now i am trying to make a project (from scratch) to keep an eye around my house (RC car + cam). I have developed a motor driver for it, but can’t make sure if it will work or not.
I have posted it on github so that some expert can verify the design, so i could start work on the board design.

Post an image file here, you might get someone replying.

Most people will not be able to open a .SCH file . If you want any feedback you need to post the schematic in a format everyone can open , like PDF or jpeg.. If you have to take a photo with your cell phone and post that.

That PNG file is far too big to view easily. Reduce it to 640x480 or 1280x960.

Why not just buy an off-the-shelf motor driver? - especially if you learned nothing in school :slight_smile:

...R

Use this link to view the large picture. Reducing size will make it hard to see.

Robin2:
Why not just buy an off-the-shelf motor driver? - especially if you learned nothing in school :slight_smile:

I have already made projects using driver shield, now want learn to make my own. 8)

What values did you choose for R1 & R2 ?

raschemmel:
What values did you choose for R1 & R2 ?

R1 = 1 ?
R2 = 56k?

R1 is 1 ohm , correct?

raschemmel:
R1 is 1 ohm , correct?

Yes.

2 Watt ?

1/4 Watt

Thanks

First, I applaud your efforts to get hands-on experience; it will lend a lot of relevance to what you learned is school-Especially when that 1/4W shunt resistor catches fire :slight_smile: I just took a look over your board layout and had a few thoughts I would share.

Do you know if the update speeds for the IO with the Aduino will allow you to spoon feed the DRV8432 fast enough to get it to do anything useful? Do you plan to use the Arduino environment, or do you just plan to use AVR-Studio and the ISP? I have used several other MCU's and have been underwhelmed by the performance of the Arduino compared to the timer driven interrupts, DMA analog reads, etc I am used to. My knee-jerk reaction when I saw no MCU on the board dedicated to controlling the motor was "put an MCU directly on that thing!"

2nd thought: Beef those traces up. Use copper pours to make every connection REALLY heavy. The inductance and resistive losses are not to be underestimated. TI says use 2Oz copper. Use the layout from their evaluation board as closely as you can.

3rd thought: Ground plane/pour. You will want to provide as much shielding as you can get and keep the ground from getting jerked all over the place by the currents flowing to ground. Think about where current will flow and EXPECT ground to move up in voltage along those paths--If a rise in voltage will hurt your ability to do something like read a shunt resistor or will inject ground noise into sensitive parts of your circuit, provide a separate net to ground that WON'T bounce around.

4th: Get your caps right next to the chips or functions they are there for. The inductance in the traces can render them useless if they aren't REALLY close. The smaller the cap, the closer it should be.