topic Re: SPI for NBP8 in Sensors

SPI for NBP8

CaoRq — Tue, 03 Feb 2026 20:49:20 GMT

Hi，NXP

I need to use pressure sensor NBP8, but when I try to operate it by spi, I meet some problems

when I need external host waking up the NBP8 ,should I pull up CS_B/WAKE_UP pin then pull down it again after READY/INT pin pull up? if I do it , the response for NBP8 is always 0x1002.

if I don't pull up and pull down CS_B/WAKE_UP pin ,when I try to operate register by spi , the response is always 0x2002.

can you tell me how to solve it ?

Thank you in advance

Re: SPI for NBP8

JozefKozon — Tue, 12 Sep 2023 08:25:12 GMT

Hi Cao,

please share a scope of the SPI signal when you try communicate with the NBP8. The CS_B pin must be low, when you want to wake up the NBP8 or you want to communicate with.

JozefKozon_0-1694507096672.png

With Best Regards,

Jozef

Re: SPI for NBP8

CaoRq — Tue, 12 Sep 2023 08:45:48 GMT

Thank you for you support .

I find a solution ,before I transfer a command(2 bytes) , I need to pull up and pull down the CS_B pin, then I can get the correct response. I follow the sequence shown in the image below

RunqiangCao_0-1694508252476.png

I wonder whether I can transfer many commands without pulling up and pulling down the CS_B pin?

Re: SPI for NBP8

Mason2 — Wed, 17 Jan 2024 10:12:06 GMT

Mason2_0-1705485274021.png

Mason2_0-1705486306444.png

Re: SPI for NBP8

BillWen — Wed, 02 Jul 2025 01:53:04 GMT

Hi CaoRq:
I have a same problem with you,
if I pull up CS_B/WAKE_UP pin then pull down it again after READY/INT pin pull up, the response for NBP8 is always 0x1002. If not, I always get 0x2002.
The following is my code
void NBP8_WakeupAndCheck(void)
{
uint8_t regval = STD_LOW;
uint8_t result;
uint16_t TxChBuf[1];
uint16_t RxChBuf[1];

Dio_WriteChannel(DioConf_DioChannel_LPSPI5_PCS3, STD_LOW);

regval = Dio_ReadChannel(DioConf_DioChannel_PS_READY);
while(regval == 0)
{
Printf("DioConf_DioChannel_PS_READY = %d\r\n", regval);
}
Printf("DioConf_DioChannel_PS_READY0 = %d\r\n", regval);

Dio_WriteChannel(DioConf_DioChannel_LPSPI5_PCS3, STD_HIGH);

//Osif_Wait(100);

Dio_WriteChannel(DioConf_DioChannel_LPSPI5_PCS3, STD_LOW);
//Osif_Wait(10);

//TxChBuf[0] = NBP8_FW_DER;
TxChBuf[0] = NBP8_SPIOPS;

Spi_SetupEB(SpiConf_SpiChannel_SpiChannel_PressureSensor, TxChBuf, RxChBuf, sizeof(TxChBuf));
result = Spi_SyncTransmit(SpiConf_SpiSequence_SpiSequence_PressureSensor);
//Osif_Wait(10);
Dio_WriteChannel(DioConf_DioChannel_LPSPI5_PCS3, STD_HIGH);

if (result == E_OK) {
Printf("RxChBuf[0] = 0x%x\r\n", RxChBuf[0]);
//Printf("RxChBuf[1] = 0x%x\r\n", RxChBuf[1]);
}
}
Do you know how to fix this?

Thanks
BR, BillWen