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When I started learning electronics, I dived straight into the deep end, and missed some important beginning knowledge. I know how to use I2C communication but I don’t know what to do here.

I am making a simple h-bridge motor controller for use with an Arduino Nano clone, soon to have more channels when I get more transistors.

My question is, in the circuit below, do I need these resistors? If so, what value? It is kind of embarrassing that I don’t know this, after my four years spent doing electronics. Thanks!

the diagram

ocrdu
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Codachrome
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    There's a couple of very wrong things here. Did you find this online or draw it out yourself? – Kyle B Aug 20 '22 at 04:52
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    The easiest way to *do electronics* is to find circuits that work and adapt them to your needs. Why do you think your circuit is a h-bridge? – StainlessSteelRat Aug 20 '22 at 05:31
  • It might be more insightful question if you added what do you think the answer is, and more importantly, why, to help you analyze circuits. – Justme Aug 20 '22 at 05:45
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    Do not build this. Do not believe any circuits copied from the web if you cannot verify its functionality before - except if you can afford to lose it and everything connected to it and in some cases also your life or house. This circuit generates easily short circuits and overloads the data outputs. If the resistors are big enough, say 100 ohms, only D4 and D5 are overloaded. Do not expect any real world power or torque from a motor driven with a circuit this ineffective. –  Aug 20 '22 at 08:23
  • (continued) Is this perhaps taken from a humour video where the motor is actually used also as a generator and Arduino controls it to generate its own supply power? The lack of the explicit power supply supports this idea. –  Aug 20 '22 at 08:29
  • Where's the H-bridge? Which motors do you want to control, and what will they be used for? – Bruce Abbott Aug 20 '22 at 08:55
  • I've known many EE college graduates that couldn't design an H-Bridge. If you are just beginning to design at the component level, this is not a good place to start IMO. – Mattman944 Aug 20 '22 at 09:55
  • Ok, I won’t build it. Thanks! – Codachrome Aug 20 '22 at 15:42
  • Could some of you tell me what’s wrong here, to help me build something better? – Codachrome Aug 20 '22 at 15:43
  • The only things I could thing of were removing the diodes and replacing them with transistors, then adding diodes across the emmitters/collectors of the transistors and adding a capacitor on the power supply lines. – Codachrome Aug 20 '22 at 16:00
  • Would that work? – Codachrome Aug 20 '22 at 16:00
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    This is good solution: https://electronics.stackexchange.com/a/26131/174533 – Vladimir Aug 20 '22 at 16:42
  • Replacing diodes with transistors would make it closer to a h-bridge, but do some research on h-bridges. Figure out what you need to drive. Size the h-bridge to drive load. Figure out interface to drive h-bridge. Randomness and electronics don't mix. – StainlessSteelRat Aug 20 '22 at 18:03

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