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LSM330DLC data sheet questions

rluttrell
Associate
Posted on November 07, 2013 at 19:32

Hello,

I need to configure a LSM330DLC in a way outlined in the DT0005 document.  Essentially, on data ready interrupts (INT1_A) from the accelerometer feed into the DEN_G pin, telling the gyro to push a conversion onto the gyro FIFO.  In this way, acceleration and gyro data are aligned (I think).

In addition, I want to have a FIFO watermark interrupt as well as an interrupt to wake my board up upon movement.

I believe I need to setup three interrupts sources:

1) INT1_A to be I1_DRDY1 (or is it I1_DRDY2?)  Which one does what?

2) INT2_A to fire upon a motion detection event.  I believe I see how to do this with INT1_A, but I need it to happen on INT2_A.

3) A FIFO watermark interrupt to fire from the gyro side (INT2_G).  This one I have figured out, but need INT1_A/DEN_G working before I can fully test it.

More to the point-

1) In table 18, there are INT2_CFG_A, SOURCE_A, etc registers, but I see no mention of them in the section 8 description.  Does anyone know how to configure INT2 on the accelerometer.

2) What is the difference between DRDY1 and DRDY2? (See table 26).  In short, how do I make INT1_A fire upon every accel conversion?

3) The text after table 43 ''The content of this register is loaded at boot?''  OK, so if I want to change it do I need to reboot for the changes to take place?  I also do not see in table 18 which registers are actually loaded at boot.

4) If I am doing it properly, rebooting does not appear to wipe out FIFO count.  Is this the correct behavior.

5) What does Figure 20 mean?

Thank you in advance for your help,

Shane

#lsm330dlc-drdy-interrupt #lsm330-lsm330dlc
8 REPLIES 8
Thiago REIS
Associate II
Posted on January 06, 2014 at 12:23

Hello Shane,

You can use the Accel to trigger an interrupt on a motion with the data ready signal, so this should be ok. However when the DEN_G pin on the gyro will not make the gyro FIFO fill up, you have two ways of using the DEN_G pin, either continuous sampling with the last bit (b0) telling you if the gyro data was coming from DEN = 1 or DEN = 0, so you will have to do a data post processing to find out what happened, and then the other way is DEN on rising edge which sample a single data.

So let me know if you want me to send you an example of motion wakeup.

Here is my recommendation:

  • Set the Accel in motion wakeup with INT1 connected to DEN_G

  • Set the gyro DEN in to have a continuous sampling

Also regarding your question, INT2 can be latched by set bit 1 of REG5_A.

Thank you,

Thiago Reis

brian
Associate
Posted on February 04, 2014 at 06:57

Hello,

Could me some sample code showing how to set up INT1_A to fire for each acclerometer conversion?

Thanks.

Thiago REIS
Associate II
Posted on February 05, 2014 at 13:53

Hello Brian,

Did you have a chance to check the sample codes available for ST´s Accelerometers in the Accelerometers Forum´s section?

Thank you,

Thiago

brian
Associate
Posted on February 06, 2014 at 07:35

Hi Thiago,

I saw some examples in the accelerometer section, but they didn't help me. I can make the FIFO overflow interrupt work, but not the DRDY1 or DRDY2. Do these interrupts require additional register settings? I am not looking for any threshold or duration parameters to be met. I just want an interrupt for each accelerometer sample as it goes into the FIFO.

Thanks

Brian

joel2
Associate
Posted on April 07, 2014 at 23:24

I have the same question as Brian.

onehorse
Associate II
Posted on May 22, 2014 at 03:13

Hi Thiago,

Is there some description of what the DEN_G pin does and how to use it for the LSM9DS0 sensor? I would very much like to take advantage of what I think the capability is for the LSM9DS0 sensor but I can find no documentation nor any example of how to configure the device or its registers for use of the DEN_G pin. Please help. Thank you.

Kris

A Pantsalot
Associate
Posted on October 23, 2017 at 19:21

Hello,  I have some questions about LSM330DLC datasheet:

  1. The INT1_A, INT2_A, INT1_G, INT2_G pins have Disable/Enable bits in their respective registers.  Does setting the Disable/Enable bit tri-state the respective pin?

  2. CTRL_REG3_G has a PP_OD bit.  Which interrupt is that for?  Or is it for all 4 interrupts?

Posted on October 24, 2017 at 16:14

If none of the interrupt is enabled the INT pin is pulled down to ground, so it is not in high impedance state.

PP_OD bit in CTRL_REG3_G register configures both gyroscope interrupt pins (INT1_G,DRDY_G\INT2_G) .