FXOS8700CQ / How can we choose debounce period?

[velison1]

Hi,

I am using fxos8700cq and try to get magnetic vector-magnitude interrupt. I have to configure M_VECM_CNT (0x6C). However, I couldn't understand how I can do that. Now, sensor operates at 100 Hz and the period is 10 ms for this configuration. If I write 1 (0x01) into the M_VECM_CNT register, debounce period is 10 ms. Can you please explain me how to choose debounce period? What is the difference between choosing 10 ms or 20 ms debounce period? What is the criteria of choosing debounce period?

Best regards,

Veli

[reyes]

Hi Veli,

The magnetic vector-magnitude change detection block of the FXOS8700 can be configured to generate an interrupt when the magnetic field magnitude exceeds a preset threshold for a programmed debounce time. So, the idea is to select the debounce time that works fine for your application, with lower debounce time, it is easier to detect when the magnetic field magnitude exceeds the threshold.

You can find a diagram about the complete magnetic vector-magnitude functionality including the debounce time (M_VECM_CNT register) in Figure 2 of the application note AN4458: https://www.nxp.com/docs/en/application-note/AN4458.pdf

Regards,

Jose

NXP Semiconductors

[velison1]

Hi Jose,

I understand the idea of choosing debounce period. The application note is really helpful for me. Thank you so much.

Best regards,

Veli