Design the circuit - FAIL

A project log for Lightronome - Light Metronome

Metronome for drumers. Using light instead of sound

SUFSUF 03/14/2018 at 04:105 Comments

Based on my breadboard design I created a schematic in KiCAD, designed the PCB and ordered from ALLPCB.

The board:

It arrived in a week:

Started to populate it - here comes the problems:

Those was easily correctable.
So the build (without the display):

After resoldering the ATTINY for a few times, I was able to download the code, but nothing appeared on the display or the LEDs.
Scratching my head. Then I realized, that the ISP connector has all of the pins required to drive the TM1637. So I connected this external display to it:

It was working.
I started to measure the board, and instantly realized the problem.
The VCC and GND pins of the TM1637 was swapped. How this happened?
I mirrored the TM1637 part in the KiCAD. After this the GND pin went to the top of the drawing and the VCC to the bottom. After this I connected the power pins as usual. The VCC to the top and the GND to the bottom. IDIOT!!!!


Alain Mauer wrote 03/14/2018 at 14:06 point

Each time i design a board, something does not fit. Murphys law I gess :)

  Are you sure? yes | no

Ted Yapo wrote 03/14/2018 at 16:32 point

I always blame the components!

  Are you sure? yes | no

SUF wrote 03/15/2018 at 06:23 point

I mostly blame myself.

1. Bad component design, if I did it.

2. Why I didn't check the component before if it will fit.

  Are you sure? yes | no

davedarko wrote 03/14/2018 at 07:58 point

classic "I did that once and never again" mistakes :)

  Are you sure? yes | no

SUF wrote 03/14/2018 at 11:51 point

Yepp, never until I forget this. :-D

  Are you sure? yes | no