LIS2DE12 Event Max Values.

[JForm]

Dear support,

I'm looking for an accelerometer and the one we work with is normally LIS2DE12, but I think it does not work for the product I'm looking for.

In the INT1_SCR register, high and low interruption events can be enabled in the different axes, without further details.

I want to detect a maximum or minimum value on an axis (X, Y or Z). Is it possible with the LIS2DE12? If it is not with this, is there another accelerometer that can serve me? Can you match footprint and pinout?

Kind Regards,

Jose Ramon Formoso

[Eleon BORLINI]

​hi jose, supposing you want to set a high threshold for an "high g event detection" and a low threshold for a "low g event detection" on e.g. x axis, you can set the desired high threshold configuring the INT1_THS (32h) register, and the sign of this threshold setting the INT1_CFG (30h). You can decide to generate an interrupt if the data exceeds or not the threshold acting on INT1_SRC (31h) reg.

You can use this threshold to detect also if the data goes down to minus [INT1_THS (32h) value].

If you want to set another threshold different from the previous one but running in the same time, you can use the INT2_THS (36h) and set the desired threshold. If you want to detect a negative cross of this threshold, you can act on INT2_SRC (35h) bit0 (interrupt if X low event has been detected)

Btw, there are other PN you can use, starting from accelerometer (e.g. LIS2DW12) to 6-axis modules (LSM6DSOX), but for this purpose also LIS2DE12 should be ok. Regards

[JForm]

Hi Eleon,

Thanks for the reply. I understand the operation better.

However, this would only serve to have the same threshold in the three axes, we could not have different thresholds for the three axes. What would be the device that allows this operation?

Thanks.

[Eleon BORLINI]

There is a device, which however is obsolete, that allows you to set 3 thresholds on 4 bits: LIS331DL, but I think this could be not the right choice for the future.

​There is a better way you could set 3 threshold and 3 masks for the desired axis / direction: you can use the finite state machine embedded e.g. on LSM6DSO / OX:

[JForm]

I can also use the IIS2DLPC which is also long-life, (I understand that those that are not long-life, you would have fewer hours of operation).

If I use the registers 0x30-0x32 (TAP_THS) configuring the thresholds and then activating the corresponding interruptions, I could detect thresholds in all three

axes Correct me if I'm wrong. What would be the configuration of the interruptions?

Regards.

[Eleon BORLINI]

​Yes, this pn could be ok (even if it is for the industrial market, I don't know your real application), the threshold is on 5 bits. But note that you have to select the tap priority on the 3 MSB of reg TAP_THS_Y (31h), and you have to manage the duration of the interrupt. Regards

[JForm]

Thank you very much for the reply.

At the start-up if problems arise, I would appreciate being able to contact you again.

Kind Regards.