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Topic: Mini loses UART in PCB (Read 406 times) previous topic - next topic

magnethead794

Aug 29, 2012, 08:07 am Last Edit: Aug 29, 2012, 08:21 am by magnethead794 Reason: 1
This mini I have has been difficult all day. Finally got my program loaded on it.

I have a bunch of (typical) serial prints for debugging. The first will come through if I just plug in the FTDI's TX, RX, and ground...except, I don't understand how it's turning on and giving that first line, considering I don't have it getting 5 volts from anywhere...

One I put it in the circuit board, I can't get squat out of it. Take it back out, things print. Puck back in, nada.

I even tried plugging it into the FTDI THROUGH the circuit board (I'm using super long pins), and still didn't get anything.

Confusing as hell, need this working in 2 days....

I dont have any images of the board, I had it designed for me. But there aren't any conflicts that I can find.
KF5RVR

frank26080115

we're gonna need a circuit diagram, a text description might not be enough.

I might be misinterpreting what you are saying, but I have a theory anyways: power could be going through the TX line, just enough to power up the ATmega alone, but once it's in your circuit board, there's too many other components also drawing the same power and the ATmega does not have enough anymore to actually run code.
Freelance engineer, consultant, contractor. Graduated from UW in 2013.

magnethead794


we're gonna need a circuit diagram, a text description might not be enough.

I might be misinterpreting what you are saying, but I have a theory anyways: power could be going through the TX line, just enough to power up the ATmega alone, but once it's in your circuit board, there's too many other components also drawing the same power and the ATmega does not have enough anymore to actually run code.


I don't have the eagle files or any pictures, it was designed for me.

The Mini is fully powered off the 5V line once in the circuit board.
KF5RVR

magnethead794

I'm dumb. I was looking at the version 3 layout, not the version 4 (which i have).

Reset and ground played musical chairs. Thus reset is staying grounded where I have it, I had to bend a pin b/c I thought things were a pin off on the board. Nope, only my brain.
KF5RVR

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