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LIS3MDL connected to ISM330dhcx as external sensor is giving NACK after some hours of continous run.

Associate II

i have a maaxboard that is connected (via i2c) to ism330dhcx. Magnetometer LIS3mdl is connected(via i2c) to ism330dhcx as an external sensor.

reading magnetometer in power mode = ultra-high mode.

data rate = default

single converstion mode we get a nack saying magnetometer is not responding after 2 hours continuous run.

changed the power mode = lowe power mode and kept remaining same.

now i get MASTER STATUS of ISM330DHCX give NACK after 12 or 15hours of continuous run.

this is the schematics..
_legacyfs_online_stmicro_images_0693W00000dDIoRQAW.pngplease help.. i need to run it continously.

Federica Bossi
ST Employee

Hi @Nmaje.1​ ,

First, looking at your schematic it seems that the magnetomer is connected via SPI and not I2C.

Referring to the DS at pag 35, for I2C connection between magnetomer and ISM330DHCX you need to connect only MSDA and MSCL.

_legacyfs_online_stmicro_images_0693W00000dDPW9QAO.pngThen, at pag 37, check the pin status mode2.

At least, I suggest you to check if CSB_AUX2 is always at high level.

Let know if this helps.

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Associate II

@Federica Bossi​ 

if CSB_AUX2 is high means its i2c communication right!?

You may choose to use I2C or SPI. 

Either way, there is external pullup on all lines, specifically both I2C_SDA/SDC and SPI_nCS

also I am getting proper data from magnetometer(LIS3MDL) via mode2 as ism330dhcx I2C master. Its just that at times.. my magnetometer stop responding... make the ism330dhcx feel that the external sensor is not responding. will this be because of any incoming extra power ?