MMA8452Q Sleep, I2C and ODR

[johnmunroe]

Hi

I'm hoping to simply fire a signal on an interrupt pin when motion/transient is detected. Would it be a good idea to put the device to sleep mode but set the sleep mode ODR to a reasonably high rate? When the device is in sleep mode, is I2C completely switched off such that no draining occurs?

Thanks

[TomasVaverka · Accepted solution]

Hi John,

The advantage of the sleep mode is that the part can automatically switch to a lower ODR and another mode (usually Low Power) when inactivity is detected. The lowest current consumption is achieved when (S)MODS = 0b11 (Low Power mode) and when the sample rate is set to 1.56 Hz. Once activity (e.g. motion/transient) is detected, the accelerometer automatically switches back to the original data rate of the application and provides an activity interrupt that can be used to wake up the host processor. In the sleep mode both analog and digital blocks are still enabled.

Regards,

Tomas

PS: If my answer helps to solve your question, please mark it as "Correct". Thank you.

[johnmunroe]

Is there a way to switch off I2C (to reduce power consumption) during ACTIVE (whether wake or sleep)?

Thanks

[TomasVaverka]

Hi John,

No, there is not.

Regards,

Tomas