Why the number of data I sent is wrong when using HAL_SPI_TransmitReceive() ?

[XZou.1]

HAL_SPI_TransmitReceive(&hspi1,tx_sensor_data,rx_sensor_data,8,0);

I want sent 8bytes, but only 2bytes sent, why?​

[TDK]

You have a timeout of 0, which may be the issue. If you want it to be blocking, use HAL_MAX_DELAY.

[XZou.1 · Accepted solution]

I solved it. The general set is wrong. Must set 8 bits not 4bits or 2bits