DRDY not returning low on AIS2IH

[harrisTech]

I am using the AIS2IH and polling the DRDY bit of STATUS to see when a new sample is available .  I am using single data (on demand) mode and ODR bit is set.  The spec sheet says that DRDY returns low after the high part of X,Y or Z has been read, but for me DRDY is remaing high.  Maybe I am setting the mode incorrectly, timing soft reset badly?  Thanks.

Code :

SPIwriteOneRegister(CS_SENSOR1, CTRL_2, 0x48);  // soft reset

// Perform a read to Hi x to reset DRDY :
tmp = SPIreadOneRegister(CS_SENSOR1, OUT_X_H);

SPIwriteOneRegister(CS_SENSOR1, CTRL_1, 0x20);  // Select Single data mode

SPIwriteOneRegister(CS_SENSOR1, CTRL_2, 0x08); // Set Block Data Update to 1 

SPIwriteOneRegister(CS_SENSOR1, CTRL_3, 0); // Set SLP_MODE_SEL == 0 to enable active high external trigger line

SPIwriteOneRegister(CS_SENSOR1, CTRL_6, 0x34); // filtering etc

[Federica Bossi]

Hi @harrisTech ,

Welcome to ST Community!

Have you already tried to perform the test without the initial soft reset?

[harrisTech · Accepted solution]

Thanks I removed the reset and also increased my SPI frequency (it was only 10khz) to 500khz and now it is working!

[harrisTech]

Thanks the DRDY now looks to be working but I think I have an issue with setting the data rate etc.  I want a slow 12.5Hz mode, single-shot (low power better but high performance acceptable) and I want to low pass filter my data at ODR/20, I am trying to detect fairly slow movements. The X_L2 and X_L3 bits etc are not low so there must be an issue, also I can poll the data at ~500Hz and see significant sample changes that I should not see with this setup.  My registers are : 

SPIwriteOneRegister(CS_SENSOR1, CTRL_1, 0x28);
SPIwriteOneRegister(CS_SENSOR1, CTRL_2, 0x08);
SPIwriteOneRegister(CS_SENSOR2, CTRL_3, 0);
SPIwriteOneRegister(CS_SENSOR1, CTRL_6, 0xF4);

Thanks!