M5Unified Configuration

Factory: M5.config()
Type: m5::M5Unified::config_t

Before M5Cardputer.begin(), you can customize hardware initialization via M5.config(). This page covers the fields most relevant to M5Cardputer development.

Usage Pattern

auto cfg = M5.config();
cfg.serial_baudrate = 115200;
cfg.output_power = true;
M5Cardputer.begin(cfg, true);

M5Cardputer.begin() calls M5.begin(cfg) internally, then sets up the keyboard.

Key Config Fields for M5Cardputer

Field	Type	Default	Description
`serial_baudrate`	`uint32_t`	`0`	Serial baud rate. `0` = disabled. Set to `115200` for USB-CDC monitor.
`output_power`	`bool`	`true`	5V output on Port.A GPIO pins. For external I2C sensors.
`clear_display`	`bool`	`true`	Clear screen on startup.
`internal_mic`	`bool`	`true`	Enable internal PDM microphone (GPIO 46 data, GPIO 43 WS).
`internal_spk`	`bool`	`true`	Enable internal I2S speaker (GPIO 42 data, GPIO 41 BCK, GPIO 43 WS).
`internal_imu`	`bool`	`true`	Enable IMU. M5Cardputer has no IMU — set to `false`.
`internal_rtc`	`bool`	`true`	Enable RTC. M5Cardputer has no RTC — set to `false`.
`led_brightness`	`uint8_t`	`0`	System LED brightness (not the NeoPixel). M5Cardputer has no system LED.
`fallback_board`	`board_t`	varies	Board type if auto-detect fails. Useful: `m5::board_t::board_M5Cardputer`

M5Cardputer-Specific Hardware Table

I2C Pins

Board	Internal SCL	Internal SDA	External SCL (Port.A)	External SDA (Port.A)
M5Cardputer	— (none)	— (none)	GPIO 2	GPIO 1
M5Cardputer-ADV	GPIO 9	GPIO 8	GPIO 2	GPIO 1

M5Cardputer (standard) has no internal I2C. Only Port.A (Ex_I2C) is available externally.

Audio Pins

Component	Pin	Signal
Mic Data	GPIO 46	PDM microphone
Mic WS	GPIO 43	PDM word select
Speaker BCK	GPIO 41	I2S bit clock
Speaker WS	GPIO 43	I2S word select
Speaker DOUT	GPIO 42	I2S data output

Display Pins (ST7789 via SPI)

Signal	GPIO
MOSI	35
SCLK	36
DC	34
CS	37
RST	33
Backlight PWM	9

Other Pins

Component	GPIO
Button A	0
SD Card CS	12
IR LED	44
NeoPixel RGB	21
SD SCK	40
SD MISO	39
SD MOSI	14

No config_t fields control these pins — they are auto-set by M5Unified board detection.

Recommended M5Cardputer Config Template

#include <M5Cardputer.h>

void setup() {
    auto cfg = M5.config();

    // === Communication ===
    cfg.serial_baudrate = 115200;

    // === Power ===
    cfg.output_power = true;       // Enable 5V on Port.A for I2C devices

    // === Audio ===
    cfg.internal_mic = true;       // PDM mic on GPIO 46/43
    cfg.internal_spk = true;       // I2S speaker on GPIO 42/41/43

    // === Disable unused peripherals ===
    cfg.internal_imu = false;      // Cardputer has no IMU
    cfg.internal_rtc = false;      // Cardputer has no RTC

    // === Fallback ===
    cfg.fallback_board = m5::board_t::board_M5Cardputer;

    // === Initialize ===
    M5Cardputer.begin(cfg, true);  // true = enable keyboard

    // === Post-init LCD tweaks ===
    M5Cardputer.Display.setBrightness(128);
    M5Cardputer.Speaker.setVolume(64);
}

Minimal Config

If unsure, just call M5Cardputer.begin() — the default config works for most cases. Only customize when you need to disable unused hardware or change serial baud rate.