ADXL 345 Accelerometer (with ADXL library)


I’m trying to get the ADXL 345 up and running with the Spark Core, using the ADXL 345 library. I have tried both including the library into a project, and using the ‘no library’ variant, which talks directly to registers on the break out board.

Unfortunately, I’m not having much success at reading the X, Y and Z values at the moment (or any of the more advanced ‘tap’ features of the board.

Here is the code I’m using:

// Cabling for i2c using Sparkfun breakout with a Spar Core
// Spark Core <-> Breakout board
// Gnd         -  GND
// 3.3v        -  VCC
// 3.3v        -  CS
// Digital 0   -  SDA
// Digital 1   -  SCL

#define DEVICE (0x53) // Device address as specified in data sheet 

byte _buff[6];

char POWER_CTL = 0x2D;	//Power Control Register
char DATA_FORMAT = 0x31;
char DATAX0 = 0x32;	//X-Axis Data 0
char DATAX1 = 0x33;	//X-Axis Data 1
char DATAY0 = 0x34;	//Y-Axis Data 0
char DATAY1 = 0x35;	//Y-Axis Data 1
char DATAZ0 = 0x36;	//Z-Axis Data 0
char DATAZ1 = 0x37;	//Z-Axis Data 1

void setup()
  Wire.begin();        // join i2c bus (address optional for master)
  Serial.begin(57000);  // start serial for output. Make sure you set your Serial Monitor to the same!
  //Put the ADXL345 into +/- 4G range by writing the value 0x01 to the DATA_FORMAT register.
  writeTo(DATA_FORMAT, 0x01);
  //Put the ADXL345 into Measurement Mode by writing 0x08 to the POWER_CTL register.
  writeTo(POWER_CTL, 0x08);

void loop()
  readAccel(); // read the x/y/z tilt
  delay(500); // only read every 0,5 seconds

void readAccel() {
  uint8_t howManyBytesToRead = 6;
  readFrom( DATAX0, howManyBytesToRead, _buff); //read the acceleration data from the ADXL345

  // each axis reading comes in 10 bit resolution, ie 2 bytes.  Least Significat Byte first!!
  // thus we are converting both bytes in to one int
  int x = (((int)_buff[1]) << 8) | _buff[0];   
  int y = (((int)_buff[3]) << 8) | _buff[2];
  int z = (((int)_buff[5]) << 8) | _buff[4];
  Serial.print("x: ");
  Serial.print( x );
  Serial.print(" y: ");
  Serial.print( y );
  Serial.print(" z: ");
  Serial.println( z );

void writeTo(byte address, byte val) {
  Wire.beginTransmission(DEVICE); // start transmission to device 
  Wire.write(address);             // send register address
  Wire.write(val);                 // send value to write
  Wire.endTransmission();         // end transmission

// Reads num bytes starting from address register on device in to _buff array
void readFrom(byte address, int num, byte _buff[]) {
  Wire.beginTransmission(DEVICE); // start transmission to device 
  Wire.write(address);             // sends address to read from
  Wire.endTransmission();         // end transmission

  Wire.beginTransmission(DEVICE); // start transmission to device
  Wire.requestFrom(DEVICE, num);    // request 6 bytes from device

  int i = 0;
  while(Wire.available())         // device may send less than requested (abnormal)
    _buff[i] =;    // receive a byte
  Wire.endTransmission();         // end transmission

Here is my breadboard:

I confess to being a bit of a newbie here, and I may have bitten off more than I can chew, but would welcome any advice or guidance. Thanks!

~ M

I’m super curious… the headers on the breakout board does not look like it is soldered on?!

Also, maybe cs is not connected correctly. (I have yet to check the datasheet)

1 Like

Hey I was also wondering about that I am doing something thing similar. Have you fixed it.
Thanks Meth

Bringing this thread alive… As I haven’t been able to work with this Sensor… Has anyone figured it out yet?
Both with library and no library examples I’m unable to get any readings at all.


I feel so silly… Forgot my pullups, sorry guys.

1 Like

Hi Iv4n,

I have the same sensor. Do you have it working? Can you share your code? I’m having trouble.

thanks, Scott

Make sure you have good solder connections. That was my problem.