I can't get BMX160 CHIPID using STM32 SPI

[zx556605]

I tried to use STM32 MCU to use SPI to communicate with BMX160, but I can't get CHIPID, I already use github bmi.h and bmi.c files, please tell me which part is missing to read CHIPID normally

[fish]

Hi

BMIX60 prilimary interface defaut is I2C, need switch to SPI. Usually  we using a dummy ready to change the interface to SPI. You could refer to chapter 3.1 in BMX160 datasheet.  The read chip id process as bellow.

[zx556605]

您好魚
我已閱讀數據表
要使用SPI，CSB需要一個上升信號
我已經將CSB設置為具有上升信號
結果是錯誤代碼rslt = -3（BMI160_E_DEV_NOT_FOUND）

*In bmc.c file bmi160_init() function,
if ((rslt == BMI160_OK) && (dev->chip_id == BMI160_CHIP_ID))
This line will not be established!! rslt = -3 (BMI160_E_DEV_NOT_FOUND)
If you look at the if judgment separately, the first half (rslt == BMI160_OK) is established,
But the second half dev->chip_id == BMI160_CHIP_ID) is not established.
dev->chip_id=0
BMI160_CHIP_ID = 0xD8
Why can't my dev->chip_id = 0xD8
*對不起，請問我應該使用PIN SPI VDDIO
以下是我的接線

MCU <--------------------------> BMX160
-------------------- ------------------------
VDD ------------------------- -> VDD（3.3 V）
MISO -------------------------> MISO                  
MOSI -------------- -----------> MOSI
CLK ---------------------------> CLK
GPIO_輸出------ -------> CS
                                                VDDID ----> VDD（BMX160 VDDVDD）

[fish]

Hi,

I think you could check MISO & MOSI connection. Meanwhile, VDD&VDDIO can powered by 3.3V.

You had better check the SPI waveform with logic analyzer tool or oscilloscope.

MCU <--------------------------> BMX160
-------------------- ------------------------
VDD ------------------------- -> VDD（3.3 V）
MISO <------------------------- SDO(PIN  1)
MOSI -------------- -----------> SDX (PIN 14)
CLK ---------------------------> SCX(PIN 13)
GPIO_輸出------ -------> CS
VDDID ----> VDD（BMX160 VDDVDD）

[fish]

MCU <--------------------------> BMX160
-------------------- ------------------------
VDD ------------------------- -> VDD（3.3 V）
MISO <------------------------- SDO(PIN  1)
MOSI -------------- -----------> SDX (PIN 14)
CLK ---------------------------> SCX(PIN 13)
GPIO_輸出------ -------> CS
VDDID ----> VDD（BMX160 VDDVDD）

[zx556605]

I run bmi_init (   )

get rslt =-3 

*In bmc.c file bmi160_init() function,
if ((rslt == BMI160_OK) && (dev->chip_id == BMI160_CHIP_ID))
This line will not be established!! rslt = -3 (BMI160_E_DEV_NOT_FOUND)
If you look at the if judgment separately, the first half (rslt == BMI160_OK) is established,
But the second half dev->chip_id == BMI160_CHIP_ID) is not established.
dev->chip_id=0
BMI160_CHIP_ID = 0xD8

[fish]

Hi,

rslt == BMI160_OK, just prove the param dev of function int8_t bmi160_init(struct bmi160_dev *dev) isn't NULL pointer.

Would you please provide SPI waveform during read BMX160 chip id?