NESPi Project Part 5 – Power and Reset button board

In this blogpost I will show how to use the board with the LED and power button and reset button. We will make all the necessarily preparation, so we later can easily connect it to the Pi.

Quick Guide

  • Desolder the original cables and the LED.
  • Retrobright the buttons if needed.
  • Make new wire and cable extensions to fit the Raspberry Pi.
  • Replace the LED with a new one.
  • Mount the board to the bottom NES case.

Step 1 – Desolder the original wires and the LED

where to desolder original cables and LED

Desolder the original wires (red) and the LED (orange).

Info. The buttons were quite yellowed, so I had to retrobright them. For more details about retrobright, see blogpost “NESPi project part 1 – the Case” in this series.

Step 2 – Make new wires and cable

This is how it will be wired:

circuit diagram button board

Back to the workbench:

workbench soldering extension cables NES

Info. All wires ~35cm. Ground wire 2x 35cm.

Note. Normally black wire means negative / ground and red positive voltage. Don’t take this for granted. I have worked with cables that have this swapped. Double check with a multimeter, that can handle negative voltage, to detect which wire is what. If they are swapped the multimeter will display a negative voltage value, then you know.

Wired according to the circuit diagram:

All new wires and LED in place

Note that the +5v wire from the Pi to the LED and the 330 Ohm resistor is not soldered on the board.

Other side:

Layout of path on the board

You can follow the paths on the board to see where the connections are.

Step 3 – Mount the board to the bottom case

This is how it looks like once in place:

Power Reset button mounted in bottom case NES

With heat shrinking tubes you can make the extensions to the micro USB female and male cables to look good (red ellipse).

The wires that will connect to the Raspberry Pi GPIO pins are extended to dupont wires for easy mounting (orange ellipse).

Note. When customizing the power supply to a Raspberry Pi you can count on voltage drop caused by the cable. The power supply I’m using says 5.1V. With the Nintendo power switch and the extended cables, I measured 5.0V. The increased resistance in the cable length and power switch is causing the voltage to drop. If the voltage drops to 4.65V you will see a warning sign (yellow flash) on the upper right corner of the screen when the Pi is running:

low voltage warning sign

It indicates that the Raspberry Pi might not fully operate at lower voltage than 4.65V.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.