Space Drop Handheld Game

Complete Step-by-Step Assembly Guide

This guide walks you through the full build of the Space Drop handheld video game, including the auto-off power circuit, controls, display, and final assembly into the enclosure.

The goal is not just to assemble a kit.
The goal is to build a handheld game that:

• Turns on instantly
• Plays immediately
• Shuts itself completely off
• Can sit on a shelf for months and still work

Follow the steps in order. The build sequence matters because some parts block access to others if installed too early.

The Parts

Before heating the iron, confirm you have:

Core electronics

• Space Drop PCB
• Microcontroller board (D1 Mini or Nano)
• OLED display (0.96" I2C)
• Piezo buzzer
• Momentary push button
• Potentiometer with knob
• Optocoupler
• NPN transistor
• Resistors (for latch and LED)
• Capacitor
• LED indicator

Power system

• 3×AAA battery holder
• Battery springs/clips
• 3 AAA batteries

Mechanical

• Header pins (male and female strips)
• 3D printed case
• Mounting hardware if included

Lay everything out before starting. Compare with the board silkscreen so you know where each part will go.

Tools

• Soldering iron (fine tip)
• Solder (with flux core)
• Flush cutters
  

Step-by-step build

Step 1 — Install resistors

• Location: Back of PCB near optocoupler and transistor area
• Insert each resistor into its labeled footprint.
• Solder and trim leads.

Step 2 — Install capacitor

• Place the small capacitor in its marked footprint.
• Solder and trim.

This helps debounce the button.

Step 3 — Install optocoupler

• Find the dot in the upper left corner of the IC. Make sure it faces upwards.
• Match it to the PCB outline.
• Insert, hold flat, solder one corner pin, then the rest.

The optocoupler isolates the microcontroller from the power latch.
It ensures the system turns off cleanly without leakage paths.

Step 4 — Install NPN transistor

• Match the flat side of the transistor to the PCB outline.
• Insert
• solder.

This transistor switches ground for the entire system. When it turns off, the whole game loses its return path and current becomes zero.

Step 5 — Install microcontroller

• If you’re using a breadboard, start by inserting the male header pins into the breadboard. Then place the D1 Mini on top of those pins with the metal shield facing up so it sits straight and aligned.
• If you’re not using a breadboard, slide the male and female headers together first. Insert that combined set into the PCB, then place the D1 Mini on top and solder everything in place so the alignment stays correct.
• Solder

Step 6 — Install buzzer

• Place the buzzer in the circular footprint labeled on the board.
• Ensure polarity matches the markings if present.
• Solder.

This produces game sound.

 

Step 7 — Install button

• Place the push button in the large center footprint.
• Ensure it sits flat.
• Solder one leg, check alignment, solder the rest.
• Install the button cap (just clicks on top)
• This single button acts as:
  • Power button
  • Fire button

It connects ground to boot. After boot, it becomes a logic input.

Step 8 — Install potentiometer

• Hold the potentiometer flush with the bottom edge of the PCB.
• Solder all pins.
• Add the knob later during final assembly.

This controls ship movement.

Step 11 — Install battery springs/clips

• Flip the board to the battery side.
• Install the metal battery clips.
• Ensure polarity matches the markings.
• Solder firmly. These joints carry all system current.

Step 12 — Install battery holder

• Start at the + sign and install a battery pin without the spring.
• Then work your way around alternating, with and without springs.
• Make sure it looks like the photo when you are done.
• Solder mounting points and terminals.

Important:
The battery holder is installed near the end because it blocks access to other solder points.

Step 13 — Install OLED display

• Insert OLED pins into the display spacer.
• Confirm orientation.
• Solder all pins.
• Display goes in last because it covers the pins of the microcontroller.

Step 14 — Power-on test

• Insert AAA batteries.
• Press the button (at least half a second)

Expected:

1. Display comes on
2. Game starts
3. Release button
4. Game stays on

This confirms the latch circuit is working.

 

Step 15— Auto-off test

1. Leave the game idle for 30 seconds.
2. After timeout, it should shut down fully.
3. Press button again.
4. Game should start instantly.

Step 16— Install into enclosure

Place PCB into case.

• Align the top corners while holding the PCB at an angle. Push the bottom section down until it clicks.
• Install knob on potentiometer.

Step 17— What you built

You now have a handheld game that you built! Features include…

• A single button for power and gameplay
• Completely disconnects battery power when off
• Draws zero current on the shelf
• Starts instantly
• Super-addictive to play!