BMA456 was shown as disabled

[freedom-168]

Hi,

I have one nrf52840 board and one bosch BMA456 Shuttle board 3.0 flyer.

I am using zephyr-sdk-0.16.8.

zephyr build and flashing works fine, but when I use device list to shown the device status.

bma456 was shown as bma4xx@19    (disabled) 

read chip information always return IO ERROR.

May I know what may cause bma456 in disabled state and how to fix it?

Thanks/Gavin

[Charlie]

Hi Gavin,

Make usre your device is enable with status="okay".

You can refer to samples mentioned in https://github.com/zephyrproject-rtos/zephyr/discussions/68250#discussioncomment-8289679 for its usage.

Best regards,

Charlie

[freedom-168]

Hi Charlie,

Thanks for your quick response. Here is the DTS overlay file I am using.

&i2c0 {
    status = "okay";
    bma4xx: bma4xx@19 {
        compatible = "bosch,bma4xx";
        reg = <0x19>;
        int1-gpios = <&gpio0 28 GPIO_ACTIVE_HIGH>;
    };
};

Someone said that a pull up resistor should be added for SCL and SDA line; others said that some boards already provide the pull up resistor within it.

May I know whether nrf52840 has built-in pull up resistor for SCL/SDA ?

Is there any other thing I could investigate for this issue?

Regards/Gavin

[Charlie]

Hi Gavin,

nRF52840 does have internal pull you can configure with devicetree.

See the following solution from my colleague:

 RE: Do I need pull-up resistors when using I2C or does the driver set them up in software? 

Best regards,

Charlie