LSM6DS3 : Who-Am-I value not valid

[surya pradhan]

Posted on June 23, 2017 at 15:24

Hello,

I am interfacing SPI based LSM6DS3 accelerometer to imx7 based board. I got LSM6DS3 driver from  '

https://github.com/STMicroelectronics/STMems_Linux_Input_drivers

'. Added device tree for this (kernel-4.1.15) as below.

        lsm6ds3@0{

                compatible = 'st,lsm6ds3';

                reg = <0>;

                spi-cpha;

                spi-cpol;

                spi-max-frequency = <50000>;

                interrupt-parent = <&gpio2>;

                interrupts = <26 IRQ_TYPE_EDGE_RISING>;

                status = 'okay';

         };

But still my device is not detected. i am getting error as 'LSM6DS3 : Who-Am-I value not valid'.

Next when i printed the valued of 'wai' , i got 0x0 , which should be 0x69.

Any suggestion

Thanks & regards

Surya

#accelerometer #lsm6ds3 #mems-accelerometer

Posted on June 23, 2017 at 16:36

Hello, can you post the schematics to verify your design?

Do you have a logic analyzer to verify that the sensor works alone?

David

[surya pradhan]

Posted on June 23, 2017 at 16:49

Hello David,

Its really not possible to share the schematic because of some NDA issues. But i can assure you about hardware connections. You can take reference of imx6 also.

One more thing - when i tried to comment the chip ID read register lines , the driver get probed , but still i am getting 0,0,0 values in accelerometer output which is false.

I have commented below lines in lsm6ds3_core.c probe function.

---------------------------------------------------------------------

 if (wai ! = LSM6DS3_WHO_AM_I_DEF) {

                     dev_err(cdata->dev, 'Who-Am-I value not valid');

                     return -ENODEV;

}

---------------------------------------------------

Thanks & regards

Surya

Posted on June 24, 2017 at 21:07

Hello,

I would start with verifying that the sensor works, using an external logic analyzer.

Then, write your own simple code to read the WHO_AM_I register over SPI to verify your hardware. After that, focus on the firmware / drivers.

Are you able to debug your micro-controller?

David