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MMA8451Q - FIFO

Question asked by George K on May 8, 2013
Latest reply on Feb 10, 2015 by Mike Stroven

Hi,

 

I would like to ask you for help with configuration of MMA8451Q accelerometer. I need to read data at 800Hz ODR, 14 bit resolution. I'm trying to set the TRIGGER MODE to FIFO. I would like to set the accelerometer so that when watermark is reached, then the interrupt is generated.

My settings of the accelerometer is not working. Setting is as follows:

 

// FIFO TRIGGER MODE

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x2A, 0x00);// standby,800Hz,14 bit

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x09, 0xC8);// Triger, watermark = 8 dec

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x0A, 0x00);// no trig 0x00

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x2D, 0x40);// int_en_fifo = 1

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x2E, 0x40);// INT1 // 0x00 = INT2

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x0E, 0x02);// Set 8G - HP OFF

iic_acc_send(IIC_ACC_ADDR_MMA8451Q, 0x2A, 0x01);// active, 800Hz, 14 bit

 

Please can you advise me what is wrong?

 

I would also like to ask you how to implement the reading sequence in order to reset interrupt flag in accelerometer.

 

 

Thanks for your advice,

George

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