AIS2120SX sensor read data issue

[anandhram1988]

Hi , i am trying to read the sensor data of AIS2120x only for sensor ID type , i can see from the bus the data is transferred correctly, but i don't receive any data back from sensor rather its only 0.

i have attached the code snippet for this test, any leads will be helpful. JHo.1

@JHo.1 and @Eleon BORLINI @CJeff.1 

 

test 1:

CS_low();
Sensor_Write(0xD1,0x80,ubAisSensor ); // command to read address 0x0C/REG_ID_SENSOR_TYPE from AIS2120x
// according to 32 byte cmmand format 
Sensor_Write(0x00,ubCrcVal,ubAisSensor ); 
CS_high();

 

Test 2:

CS_low();
Sensor_Write(0x8C,0x00,ubAisSensor ); // command to read address 0x0C/REG_ID_SENSOR_TYPE from AIS2120x
set_high();

//Sensor interface 

void Sensor_Write(uint8 addr, uint8 Data,(uint8 Sensor) {
 // application specific
spi_Write(addr);
delay();
spi_Write(Data);
}

//receive ISR
uint8 ubSpiStatus;
uint8 RxData;
_INTERRUPT_VOID SPI_vRxISR (void)
{
if(SPIS==0xA0)
{
RxData = SPID;
ubSpiStatus = 1;
}

}
spi_Write(uint8 addr, uint8 Data,uint8 ubAisSensor)
{
while (!(SPIS)); // Wait until transmit buffer is empty
SPID = data;

while(!ubSpiStatus);
ubSpiStatus = 0;

while (!(SPIS)); // Wait until transmit buffer is empty
SPID = data;

while(!ubSpiStatus);
ubSpiStatus = 0;
appl(RxData); //evaluate data
}

i use nxp 8 bit mcu : MC9S08SH32

MCU is 5v output, level shifter used between MCU and sensor to downgrade voltage to 3V3 ,

 

[anandhram1988]

Its worked now(change is downscaled the spi clock to 500K), thanks all for the reply, but still i am not sure why the clock frequency must be less than 1Mhz even datasheet says 5Mhz.

[Andrew Neil]

The saga continues:

https://community.st.com/t5/mems-sensors/ais2120-reading-issue/m-p/817195