ATmega32U4 Schematic Review

Other Hardware Hardware Development
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Hey, im trying to make a atmega32u4 work. I will add components such as buttons and leds later but for now i just want to know if its gonna work. I will add buttons, faders and leds.

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The caps on the crystal are too large. The crystal probably will not oscillate. They should be about 22 pF.

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Thanks for replying, what do you mean about the caps? It is just a symbol right? Also what do you mean 22 pf, is that what i should set my capacitors to?

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The symbol is correct but the value for the crystal caps is too large. 22 pF is

22 picofarads.

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ohhh crystal capacitors? i thought you meant something completely else lol, thanks

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If everything will be bus powered, then connect VBUS to +5V

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Thanks, is that a full working schematic? If so, that will help ALOT with my project

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I would recommend adding a diode from Vcc to reset so if the power dips it also takes reset down. This will allow recovery from transients. What is the end project, that will have a effect on if this schematic will work in your application. As shown by Jim it will work.

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Thanks for replying, the end project is a kind of fader x samplepad for music creation

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Never been tested but it follows all the recommendations from the datasheet and app notes.
P.S. I do not show the xtal circuit but it is required.

Will you be loading a new bootloader?

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Thats perfect, and yes i will be loading a new bootloader.

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Well, I would include an ICSP header just in case you have problems with loading a new bootloader.

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Now that I think about it, no mater what you decide to do, I highly suggest that you include an ICSP header.

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Looks like a good approach. I had first get the ATmega32U4 running on its own and verify the basic power, clock, reset, and programming connections. Once that works, adding the buttons, faders, and LEDs should be much easier.

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No. You should always consider the final design up-front otherwise you may find that you missed something that is required for the additional circuitry.

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I agree. It’s better to plan the complete design first so the required circuitry, connections, and space are accounted for from the beginning. That can save a lot of redesign work later.