enum error_t accelEnableFreefall(void (* event_cb)(void))
{
if (!event_cb) {
return ERR_ACCEL_INVALID_ARG;
}
m_freefall_event_cb = event_cb;
/* Enable freefall detect on y; Event latch disable */
accelWriteReg(ACCEL_REG_FF_MT_CFG, 0x10u);
/* Enable freefall detect */
accelWriteReg(ACCEL_REG_CTRL_4, 0x04u);
/* Freefall interrupt to INT2 pin */
accelWriteReg(ACCEL_REG_INT_PIN_MAP, 0x04u);
/* Push pull, active high */
accelWriteReg(ACCEL_REG_CTRL_3, 0x00u);
/* Set threshold. Max = 0x7f, which equals 8 G */
accelWriteReg(ACCEL_REG_FF_MT_THS, 0x13u);
/* Set freefall debounce timeout */
accelWriteReg(ACCEL_REG_FF_MT_COUNT, 0X00);
/* Set ACTIVE bit to wake chip */
accelWriteReg(ACCEL_REG_CTRL_1, 0x01u);
/* Interrupt on INT1. Rising edge. */
EICRA |= _BV(ISC11) | _BV(ISC10);
EIMSK |= _BV(INT1);
return ERR_NONE;
}
enum error_t accelDisable(void)
{
/* Put the accelerometer into standby mode */
accelWriteReg(ACCEL_REG_CTRL_1, 0x00);
/* Disable the interrupt */
EIMSK &= ~_BV(INT1);
return ERR_NONE;
}
/*
Initializes the accelerometer and it's I2C channel
*/
void initI2CAccel(Accel *a, I2C_MODULE i2c){
a->read = 0x3b; // read accel device value
a->write = 0x3a; // write accel device value
a->I2C = i2c; // I2C channel for accel device
I2CSetFrequency(a->I2C, //100 Hz
10*1000*1000, 100);
I2CEnable(a->I2C, 1); // turn on
accelWriteReg(a, 0x2d, 0x8); // set to measure mode
}