Hi,
I am using the NBP8FD4ST1 pressure sensor with the S32K146 microcontroller. The CS_B/WAKE-UP pin of the sensor is connected to a GPIO pin on the microcontroller.
The logic analyzer signal mapping is as follows:
- D0 → SCLK
- D1 → CS_B
- D3 → READY
- D5 → MISO
- D7 → MOSI
During the communication sequence, when I pull the CS_B pin low to request SPI communication, the READY pin is asserted as expected. After READY goes high, I send the SPIOPS register read command (0x00E1). However, the sensor always returns 0x0000 on MISO. As a result, the firmware validation fails, and the CS_B pin is subsequently driven high to terminate the transaction.
Could you please help me understand whether my SPI communication sequence is correct or if I am missing any required step, such as the wake-up sequence, dummy transfer, or SPIOPS handling described in the datasheet?
I have also attached the logic analyzer screenshots for reference.
Thank you in advance for your support.
Best regards,
Pratyusha.
Hi Pratyusha,
Please note that NXP's MEMS Sensors business, including pressure sensors such as the NBP8FD4ST1, has been transferred to STMicroelectronics. Effective February 2, 2026, technical support, product documentation and development activities for these sensors are now handled by STM. As a result, we are unfortunately no longer able to provide technical support for the NBP8FD4ST1.
I recommend that you contact STM directly through their support channels or community forum, where the sensor experts can assist you with your implementation and communication troubleshooting.
BRs, Tomas
@suncongjohnson Thanks for your reply. I have configured the SPI peripheral for 16-bit transfers, so I expect 16 SCLK pulses to be generated for each SPI transaction. However, when issuing the SPIOPS read command, no SCLK signal is generated on the D0 (SCLK) line.
const lpspi_master_config_t lpspiCom1_MasterConfig0 = {
.bitsPerSec = 1000000U,
.whichPcs = LPSPI_PCS0,
.pcsPolarity = LPSPI_ACTIVE_LOW,
.isPcsContinuous = true,
.bitcount = 16U,
.lpspiSrcClk = 8000000U,
.clkPhase = LPSPI_CLOCK_PHASE_1ST_EDGE,
.clkPolarity = LPSPI_SCK_ACTIVE_HIGH,
.lsbFirst = false,
.transferType = LPSPI_USING_INTERRUPTS,
.rxDMAChannel = 255,
.txDMAChannel = 255,
.callback = NULL,
.callbackParam = NULL,
};