LSM9DS1 WHO_AM_I REGISTER (0x0F)

[ABin .1]

Hello,

I have difficulties to get value of 0x68(IMU) and 0x3D(Magnetometer) from LSM9DS1 WHO_AM_I Reg 0x0F.

I did on custom made board with STM32L083RZ and use I2C communication to LSM9DS1. I am using I2C3 PortC pin 0 and pin 1. The SDA&SCL are both pulled up with 4.7kOhm to VCC_MCU. CS_A/G Pin are pull-up to VCC_MCU without pullup resistor. And SDO_A/G and SDO_M pin are connected directly to STM32L0 at PortC_2 and PortC_3 which are then set(HIGH) as output_OpenDrain in GPIO Init() function. The address of slave would be 0x68<<1.

As I debug, I can see SDA& SCL are both correctly configured as Alternate Function OPEN DRAIN (AFRL=0x00000077). But the PROBLEM is I cannot read WHO_AM_I value with function below

HAL_I2C_Mem_Read (&hi2c3, LSM_ADDR_IMU|0x01,WHO_AM_I_REG,1, &check, 1, 1000);

I did change slave address to other value and it still did not return me 0x68.@

Can you help me? What is wrong.

Thank you in advance. @ST Community​ 

Regards

Anuar

[TDK]

Does HAL_I2C_IsDeviceReady return HAL_OK? If not, there is a wiring issue.

Can you see what's happening on SDA/SCL with a logic analyzer?

What is the return value of HAL_I2C_Mem_Read? And if HAL_OK, what is the value of check?

[ABin .1]

Hello @TDK​ ,

thank you for answering me. 🙂

 HAL_I2C_IsDeviceReady return HAL_OK. HAL_I2C_mem_read also returns HAL_OK of 0x00.

But I still have Who_Am_I problem which didnt return 0x68. In ISR Register of I2C_3, the BUSY FLAG is HIGH.

Do you have Idea? Thank you. 

Regards

Anuar