stc15w单片机mpr121触摸按键实例

【实例简介】
【实例截图】
【核心代码】
#include "mpr121.h"

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

struct mpr121_init_register {
u8 addr;
u8 val;
};

static const struct mpr121_init_register init_reg_table[] = {
{ MHD_RISING_ADDR, 0x1 },
{ NHD_RISING_ADDR, 0x1 },
{ MHD_FALLING_ADDR, 0x1 },
{ NHD_FALLING_ADDR, 0x1 },
{ NCL_FALLING_ADDR, 0xff },
{ FDL_FALLING_ADDR, 0x02 },
{ FILTER_CONF_ADDR, 0x04 },
{ AFE_CONF_ADDR, 0x0b },
{ AUTO_CONFIG_CTRL_ADDR, 0x0b },
};

void mpr121_phys_init(void)
{
const struct mpr121_init_register *reg;
unsigned char usl, lsl, tl, eleconf;
u32 i, t, vdd;

/* Set up touch/release threshold for ele0-ele11 */
for (i = 0; i <= MPR121_MAX_KEY_COUNT; i ) {
t = ELE0_TOUCH_THRESHOLD_ADDR (i * 2);
i2c_reg_write(I2C_MPR121_ADDR, t, TOUCH_THRESHOLD);
i2c_reg_write(I2C_MPR121_ADDR, t 1, RELEASE_THRESHOLD);
}

/* Set up init register */
for (i = 0; i < ARRAY_SIZE(init_reg_table); i ) {
reg = &init_reg_table[i];
i2c_reg_write(I2C_MPR121_ADDR, reg->addr, reg->val);
}


/*
* Capacitance on sensing input varies and needs to be compensated.
* The internal MPR121-auto-configuration can do this if it's
* registers are set properly (based on pdata->vdd_uv).
*/
vdd = VDD_UV / 1000;
usl = ((vdd - 700) * 256) / vdd;
lsl = (usl * 65) / 100;
tl = (usl * 90) / 100;
i2c_reg_write(I2C_MPR121_ADDR, AUTO_CONFIG_USL_ADDR, usl);
i2c_reg_write(I2C_MPR121_ADDR, AUTO_CONFIG_LSL_ADDR, lsl);
i2c_reg_write(I2C_MPR121_ADDR, AUTO_CONFIG_TL_ADDR, tl);

/*
* Quick charge bit will let the capacitive charge to ready
* state quickly, or the buttons may not function after system
* boot.
*/
eleconf = MPR121_MAX_KEY_COUNT | ELECTRODE_CONF_QUICK_CHARGE;
i2c_reg_write(I2C_MPR121_ADDR, ELECTRODE_CONF_ADDR,
eleconf);
}

void mpr121_sample_interval(u8 value)
{
if ((value >= 1) && (value <= 7))
i2c_reg_write(I2C_MPR121_ADDR, FILTER_CONF_ADDR, value);
}

/*
void mpr121_suspend(void)
{
i2c_reg_write(I2C_MPR121_ADDR, ELECTRODE_CONF_ADDR, 0x00);
}

void mpr121_resume(void)
{
i2c_reg_write(I2C_MPR121_ADDR, ELECTRODE_CONF_ADDR, MPR121_MAX_KEY_COUNT);
}*/