Reading any register from IIS3DWB sensor only yields 11111111

[xl]

Hello,

I have run into an unexpected problem when trying to read registers from the IIS3DWB sensor. The setup is attached in the picture. I am using an Arduino Uno R3 and an STEVAL MKI208V1 board. The code is fairly simple so I am not sure what is going wrong when I try to read any of the registers via SPI.

#include <SPI.h>

const int chipSelectPin = 10;

void setup() {

  // put your setup code here, to run once:

  pinMode(chipSelectPin, OUTPUT);

  digitalWrite(chipSelectPin, HIGH);

  Serial.begin(9600);

  writeRegister(0x0D, 0x01); // Accelerometer data-ready interrupt on INT1

  writeRegister(0x15, 0x00); // 3-axis mode enabled

  writeRegister(0x10, 0xA0); // Enable accelerometer (ODR = 26.667 kHz, FS = +-2 g)

}

void loop() {

  uint8_t temp = readRegister(0x0F);

  Serial.println(temp, BIN);

  delay(1000);

}

uint8_t readRegister(uint8_t reg) {

  SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));

  digitalWrite(chipSelectPin, LOW);

  SPI.transfer((reg & 0x7F) | 0x80);

  uint8_t temp = SPI.transfer(0);

  digitalWrite(chipSelectPin, HIGH);

  SPI.endTransaction();

  return temp;

}

void writeRegister(uint8_t reg, uint8_t value) {

  SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));

  digitalWrite(chipSelectPin, LOW);

  SPI.transfer(reg & 0x7F);

  SPI.transfer(value);

  digitalWrite(chipSelectPin, HIGH);

  SPI.endTransaction();

}

Any help would be appreciated!

[Federica Bossi]

Hi @xl ,

Welcome to ST Community!

Can you share the schematic to understand how you connected the micro to the STEVAL MKI208V1?

Thanks

[xl · Accepted solution]

@Federica Bossi 

It's okay. I managed to read the registers using a Raspberry Pi instead. Thanks!