How to use the high pass filter correctly

EEstr.1 · ‎2020-05-08

I would like to use the high pass filter with the LIS3DH sensor, but when I select it I see results of value = 0.00, why?

MGolm.1 · ‎2020-05-10

How about FDS bit in CTRL_REG2? Did you set it? And tell us more about your settings on registers to find out the issue.

EEstr.1 · ‎2020-05-10

Yes, the FDS bit set it to '1'. The registers are OK, because I select the selection mode OK in register CTRL_REG2; the cutoff frequency too and I enable the FDS bit. The thing is that I don't understand very well how to use REFERENCE. In general I don't know how to use the high pass filter, I only know how to set the register CTRL_REG2 to work but I don't know if something has to be done later because I read 0.00 all the time.

PS: I want to use the high pass filter to read by output without using the interruption.

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MGolm.1 · ‎2020-05-10

You still didn't give us your details of registers. You have to consider the ODR and you are allowed to use High pass filter just in low power mode .The cutt-off you select is related to ODR and can be set with CTRL_REG2 registers. To be honest i'm struggling with LIS3DH high pass filter for several days but i don't understand the right usage of reference yet and I think bad document from ST and even their Application note are responsible for this time killing process.

EEstr.1 · ‎2020-05-11

Hello, the problem I have is that I do not understand how to configure the REFERENCE register, as you say, because it does not indicate in the LIS3DH dataset how to do it. I also didn't know that the high pass filter can only be used in low power mode.