Quick build

Build your own Core8Bit in one evening. It is free for your own build. Want to sell consoles you build? You can, read the rules. This page only says what goes where and what connects to what. When you need more detail, the full build guide has it.

There are two ways to build it:

	A. Wired	B. Mainboard
What holds the modules	a 3D-printed base plate	a home-made PCB of the same shape
How they connect	wires	tracks on the board
Status	works today	in development

Safety. Solder only with the battery disconnected. Check battery polarity twice. Do not heat the battery.

What you need#

• Parts: the parts list (core board, 4.3" screen, ESP32, two 5 V boost modules, 21 V backlight booster, charger board, Li-Po 606090, PAM8406 amplifier, 2 speakers, 2 sticks, 10 buttons, microSD).
• Tools: soldering iron, multimeter, a 3D printer (or a printing service).
• Firmware: flashed from the flash page in your browser.

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A. Wired build#

1. Print the case#

Download the case files (zip) and print them: PLA or PETG, 0.2 mm layers. Free for your own build: one click to accept the agreement before the first download. The speaker enclosures are sold separately on our itch.io page.

File	Part
case-top.stl	front of the case
case-back.stl	back cover
base-plate.stl	base plate: holds the buttons and sticks in front, the modules behind
screen-frame.stl	holds the screen and the battery
spk-L.stl, spk-R.stl	speaker enclosures (itch.io, not in the zip)

2. Flash before you assemble#

Open the flash page in Chrome or Edge and follow it. It flashes both chips over USB, no programmer and no software needed:

1. Console (STM32): hold BOOT0, plug in the core board's USB port, click Flash console.
2. Wi-Fi module (ESP32): plug in its USB-C, click Flash Wi-Fi module.
3. SD card: format FAT32 and copy the system files onto it.

3. Put everything on the base plate#

Front side:

• D-pad on the left, A/B/X/Y on the right, MENU and SELECT in the middle (button legs into the holes).
• Two sticks at the bottom.
• The screen goes into the screen frame, the battery behind the screen.

Back side (modules sit on the posts of the base plate, glue comes later):

• core board in the centre, SD slot reachable;
• ESP32 at the top, its USB-C at the right edge (looking at the screen);
• two FFC adapters: one next to the core board, one at the screen ribbon;
• amplifier in the middle, under the window for its volume knobs;
• charger and boosts at the bottom left.

4. Wire it#

Names like R12.1 are positions on the core board headers (right block, position 12, row 1). contact n is a pad on an FFC adapter.

Screen#

The ribbon goes from the core board's "LCD interface" connector to the first adapter. Most screen lines come from there, the rest from the headers. Each line ends on the screen-side adapter.

Each adapter folds the ribbon, which reverses the pin order. Always connect by signal name, not by pad number.

Signal	From the core board	To screen-side adapter contact
CLK	board-side adapter contact 30, through 33 Ω	11
HSYNC	R26.2, through 33 Ω	9
VSYNC	board-side adapter contact 32, through 33 Ω	8
DE	board-side adapter contact 33, through 33 Ω	7
DISP	R12.1	10
R3 · R4 · R5 · R6 · R7	R7.2 · contact 16 · R3.2 · R6.1 · contact 10	33 · 32 · 31 · 30 · 29
G2 · G3 · G4 · G5 · G6 · G7	R22.2 · R24.1 · R2.2 · contact 17 · R2.1 · R13.1	26 · 25 · 24 · 23 · 22 · 21
B3 · B4 · B5 · B6 · B7	contact 24 · contact 25 · R7.1 · R19.2 · R19.1	17 · 16 · 15 · 14 · 13
3.3 V	R20.1	37
GND	GND	38, 12, 5 and the unused colour bits 36–34, 28–27, 20–18
Backlight + / −	21 V booster output + / −	39 / 40

Leave board-side adapter contact 40 free. Wrap the ribbon and both adapters in foil tape over Kapton and connect the foil to GND.

Buttons#

Every button connects its pin to 3.3 V when pressed (never to GND). One common 3.3 V wire goes to all buttons, plus one wire per button:

UP	DOWN	LEFT	RIGHT	A	B	X	Y	MENU	SELECT
contact 31	contact 27	contact 28	R8.2	contact 6	contact 7	contact 8	contact 9	R9.2	contact 26

Sticks#

Each stick axis: ends to 3.3 V and GND, middle pin to the core board.

Right X	Right Y	Left X	Left Y
L22.2	L24.1	L23.2	L25.1

ESP32#

ESP32 pin	Core board	Note
GND	R17.2
VIN	5 V from boost #1
D18	R17.1	33 Ω at the core board
D23	R22.1	33 Ω at the core board
D19	R23.2	33 Ω at the ESP32
D5	R14.2	33 Ω at the core board, plus 10 kΩ from D5 to 3.3 V
D4	R13.2

Power#

battery ─► charger board ─┬─► boost #2 ─► ferrite bead ─► 5 V to the core board
                          └─► boost #1 ─► ferrite bead ─► 5 V to ESP32, amplifier, 21 V booster
                              EN ◄─ R24.2, plus 100 kΩ from EN to GND

Set both boosts to 5.0–5.1 V and the 21 V booster to about 19 V before you connect anything.

Sound#

From	To
R9.1 (left) · R3.1 (right)	amplifier LIN · RIN
core board GND	amplifier input GND (twist it with the two signal wires)
5 V from boost #1	amplifier VCC / GND
amplifier LOUT+ / LOUT− · ROUT+ / ROUT−	left speaker · right speaker (never connect the − outputs to GND)

Interference on the wired build#

Loose wires pick up noise. You may see it on the screen (the picture drifts, rows of wrong pixels crawl across it) or hear it in the speakers (hiss or rustle when nothing plays). To prevent it:

1. Tape the solder joints on both FFC adapters and the screen connector with Kapton or electrical tape.
2. Wrap foil over the tape: the ribbon, both adapters and the screen wires.
3. Ground the foil: one wire from the foil to GND at one point.
4. Keep the screen and sound wires away from the boost modules and the 21 V booster.
5. Twist each sound wire with its ground wire, and the speaker wires in pairs.
6. If the picture still jitters, use 47 Ω instead of 33 Ω on CLK, HSYNC, VSYNC and DE.

Keep the foil away from the ESP32 antenna (the end of the module with the zigzag track). The mainboard build does not need any of this: its ground layer does the job.

5. Close the case#

1. Glass, then screen, then battery into the screen frame.
2. Speakers into the speaker enclosures, tight, with no air gaps.
3. Into the case front: speaker enclosures, screen frame, base plate.
4. Power on once before closing (next step).
5. Back cover on, 4 corner screws.

6. First power-on#

1. Measure both boost outputs: 5.0–5.1 V. Core board 3.3 V pin: 3.25–3.35 V.
2. Power on: the boot screen appears and the launcher shows the games.
3. SELECT → Settings → Sticks: calibrate the sticks.
4. SELECT → Settings → WiFi: connect to your network.

Something not working? See troubleshooting.

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B. Mainboard build#

In development. The board files will be published here when the board is ready.

With the mainboard, the board replaces the base plate and all the wires.

1. Make the board at home (toner transfer and etching) or order it.
2. Make the vias: push a thin tinned copper wire through each via hole and solder it on both sides. Do this first, before any parts.
3. Solder the small parts: resistors, ferrite beads, filters.
4. Buttons and sticks on the front side.
5. Modules on the back, on pin headers: core board (chips facing the board), ESP32 (its corner hole on the corner screw of the case), amplifier, boosts, charger, 21 V booster. Solder their pins to the tracks.
6. Screen frame: push its pins through the holes in the board and melt the ends on the back side.
7. Flash, close the case and power on as in A: steps 2, 5 and 6.

Details: mainboard.