wiipad.cpp

// Support for Wii Classic Controller and similar devices over I2C
// SHOULD NOT BE USED right now. Although it "works" in the sense
// that the game-select menu can be navigated, program CRASHES HARD
// when copying ROM file to flash. Perhaps RAM constraint or ?

#if WII_PIN_SDA >= 0 and WII_PIN_SCL >= 0

#include "pico/stdlib.h"
#include "hardware/i2c.h"
#include "wiipad.h"

void wiipad_begin(void) {
    i2c_init(WII_I2C, 400000);
    gpio_set_function(WII_PIN_SDA, GPIO_FUNC_I2C);
    gpio_set_function(WII_PIN_SCL, GPIO_FUNC_I2C);
    gpio_pull_up(WII_PIN_SDA);
    gpio_pull_up(WII_PIN_SCL);
    uint8_t init1[] = { 0xF0, 0x55 };
    uint8_t init2[] = { 0xFB, 0x00 };
    i2c_write_timeout_us(WII_I2C, WII_ADDR, init1, 2, false, 100);
    sleep_ms(100);
    i2c_write_timeout_us(WII_I2C, WII_ADDR, init2, 2, false, 100);
}

uint8_t wiipad_read(void) {
    static constexpr int LEFT = 1 << 6;
    static constexpr int RIGHT = 1 << 7;
    static constexpr int UP = 1 << 4;
    static constexpr int DOWN = 1 << 5;
    static constexpr int SELECT = 1 << 2;
    static constexpr int START = 1 << 3;
    static constexpr int A = 1 << 0;
    static constexpr int B = 1 << 1;

    uint8_t v = 0;
    uint8_t req[] = { 0x00 };
    uint8_t buf[6];
    i2c_write_timeout_us(WII_I2C, WII_ADDR, req, 1, false, 100);
    sleep_us(200);
    if (i2c_read_timeout_us(WII_I2C, WII_ADDR, buf, sizeof buf, false, 600) == sizeof buf) {
        if (!(buf[5] & 0x01)) v |= UP;
        if (!(buf[4] & 0x40)) v |= DOWN;
        if (!(buf[5] & 0x02)) v |= LEFT;
        if (!(buf[4] & 0x80)) v |= RIGHT;
        if (!(buf[5] & 0x10)) v |= A;
        if (!(buf[5] & 0x40)) v |= B;
        if (!(buf[4] & 0x10)) v |= SELECT;
        if (!(buf[4] & 0x04)) v |= START;
    }

    return v;
}

void wiipad_end(void) {
    i2c_deinit(WII_I2C);
    gpio_set_pulls(WII_PIN_SDA, 0, 0);
    gpio_set_pulls(WII_PIN_SCL, 0, 0);
    gpio_set_function(WII_PIN_SDA, GPIO_FUNC_NULL);
    gpio_set_function(WII_PIN_SCL, GPIO_FUNC_NULL);
}

#endif // end WII_PIN_SDA + WII_PIN_SCL