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Tackling the MCU / level shifter

A project log for Election Countown Display

A giant 9 panel display using WS2812 chip LEDs

criptastichackerCriptasticHacker 07/07/2023 at 18:070 Comments

Now that we have a somewhat safer power supply setup, and a way to attach things they don't fall off, it's time to dig into the microcontroller stuff.

The first thing I had to do was figure out the slight wiring mess.  Fortunately, the previous hacker labelled many wires.  So it was largely a matter of cross-referencing those markers to the Node32 (ESP32 module) pinout and the respective LED boards.  The sample test code helped a lot, since it had some info as well.

After that, I assembled a perfboard module.  



However, realizing how much time it was taking and also finding out I'd have *much* more lead time to finish this all, I opted to design a custom board.  

These days I really shy away from "one-off" hand-soldered solutions, especially with an open source, reproducible design like this.  It makes greater sense to develop a board that can be shared with others, updated, and re-made if there's a failure of some kind.

I searched for a "Node32" Eagle CAD footprint.  One came up, but as usual, it was a bit janky.  It had the wrong pin spacing and nothing was labelled.  The schematic symbol didn't label all GPIO pins, either. :/

Time to make my own..

I also designed a custom nice level shifter PCB for the 74HC245.  Confident this will work great when it gets back from the fab:

Now it's onto making a combined board with the Node32.  Ideally with a disaply and control output, and the necessary pin header or Ethernet connector.  Some output plugs for voltage readings would be nice, too ;)


[To be continued....]

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