Hardware Notes

This page collects the hardware assumptions and wiring notes for the current PicoDMZ build.

Main Components

• RP2040 or RP2350-based Pico board
• SPI TFT display
• microSD reader
• optional MAX98357A audio output
• optional RC522 NFC reader
• optional original DMG-LCD-06 board for buttons

Display Compatibility

The firmware currently supports these SPI LCD controllers selected at build time:

• ILI9225
• ST7789

Display type is not auto-detected. If your module uses another controller such as SSD1306, SH1106, or ST7735, it needs a dedicated driver path.

Pinout: Standard Buttons + MAX98357A

• UP = GP2
• DOWN = GP3
• LEFT = GP4
• RIGHT = GP5
• BUTTON A = GP6
• BUTTON B = GP7
• SELECT = GP8
• START = GP9
• SD MISO = GP12
• SD CS = GP13
• SD SCK = GP14
• SD MOSI = GP15
• LCD CS = GP17
• LCD CLK = GP18
• LCD SDI = GP19
• LCD RS = GP20
• LCD RST = GP21
• LCD LED = GP22
• MAX98357A DIN = GP26
• MAX98357A BCLK = GP27
• MAX98357A LRC = GP28

Computed Pinout

GPIO	Used by	Signal
GP2	DMG matrix	P11
GP3	DMG matrix	P14
GP4	DMG matrix	P13
GP5	DMG matrix	P12
GP6	DMG matrix	P10
GP7	DMG matrix	P15
GP10	RC522	CS / SDA / SS
GP11	RC522	RST
GP12	SD + RC522	MISO
GP13	SD	CS
GP14	SD + RC522	SCK
GP15	SD + RC522	MOSI
GP16	RC522	optional IRQ
GP17	ST7789	CS
GP18	ST7789	SCK
GP19	ST7789	MOSI
GP20	ST7789	DC / RS
GP21	ST7789	RST
GP22	ST7789	BL / LED
GP26	MAX98357A	DIN
GP27	MAX98357A	BCLK
GP28	MAX98357A	LRC

DMG-LCD-06 Button Matrix Wiring

If you are reusing the original DMG-LCD-06 board only for buttons, this branch uses a sequential GPIO mapping by ribbon pin number:

• ribbon pin 4 (P11) -> GP2
• ribbon pin 5 (P14) -> GP3
• ribbon pin 6 (P13) -> GP4
• ribbon pin 7 (P12) -> GP5
• ribbon pin 8 (P10) -> GP6
• ribbon pin 9 (P15) -> GP7

Enable this mode at build time with:

• -DRP2040_GB_USE_DMG_BUTTON_MATRIX=ON

The firmware scans the DMG matrix with active-low logic, using P14/P15 as select lines and P10..P13 as read lines.