Trying to create a custom Arduino PCB but so far have not had success

Projects General Guidance
1

I have been trying to create my own custom Arduino PCB for a project I'm working on for a while now. I designed up a schematic prior to the one I have posted pictures of with no decoupling capacitors. I have now added those and added resistors between the transmit and receive lines of the atmega328pb. Does this schematic look correct or am I missing something glaringly obvious.

Any replies are really appreciated as I'm losing my mind with the amount of boards I have ordered and don't work haha.

Thanks a lot!

:slight_smile:

Arduino PCB Thingy.PNG

2

Why do you think the problem is in the schematic?

3

Because I am inexperienced and the PCB's I have had produced by JLCPCB dont work. I cant communicate with the atmega properly and any sketch I upload to the board via ISP uploads but doesnt operate correctly, just does random things. Just wanted to eliminate the possibility that I haven't done the schematic properly.

Thanks

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5

the PCB's I have had produced by JLCPCB dont work

Does the setup work when components are breadboarded, according to the schematic?

Are the PCBs correct, according to the schematic?

Are the proper components mounted in the correct orientation, in the correct places on the PCB?

Are all the connections soldered properly, with no solder bridges? Check with a magnifying glass.

Have you verified all PCB connections using a continuity tester?

Are all voltage levels as expected?

Are connections to the PCB correct and continuous?

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7

So there isn't anything wrong with the schematic? Would there be something wrong if I didn't have the decoupling capacitors? I just want to isolate the schematic being or not being the issue first.

Thanks guys :slight_smile:

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9

Your schematic seems cut off at the bottom? Is there more to it.

Decoupling capacitors are a must to have a working board! The more the merrier.

Double check that "TX" and "RX" are connected correctly. It seems you may have gotten them mixed?

Finally, can you explain step by step -
Power on
What connections are you using?
ICSP running?
ICSP succesful?
What does the board do?

10

The reset button is wired incorrectly. Try to cut that track or remove the switch on the boards you already have.

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Okay so thanks for pointing out the reset button il fix that, currently there is no button soldered on so it wont be that. Uploading sketches via ISP works but dont run correctly. Seems like they are going really fast or something not sure. My boards only had the decoupling on the ch340g chip. My schem has more of them. And the bit at the bottom is for something else and does not contain the arduino part.

Sorry for the slow replies and what seemed to be me ignoring spycatcher2k, my apologies I didnt see the post.

Thanks everyone

12

My boards only had the decoupling on the ch340g chip

That is certainly a problem.

my apologies I didnt see the post.

Did you see reply #4? If not, it lists several other possible problems for you to consider, and tests to run.

Why have you not posted the layout?