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[bGatti]

This is a Sketch to Support the LIS302DL (least expensive 3Axis Accellerator at Sparkfun)

Tested with 5.6K pullups on data lines
SCL to 5 (5.6K pull-up)
MIS1 to 4 (5.6K pull-up)
MIS0 to Vcc
Vcc = 5vdc

Please enjoy and improve.
Wish List:
Better signal detect
Read Data only if Present (status bits)

Code: Select all

#include <Wire.h>

#define i2cID 0x1D

//TWI (I2C) sketch to communicate with the LIS302DL accelerometer - Modified and tested Ben Gatti - 6/9/2008
//http://www.st.com/stonline/products/literature/ds/12726.pdf
//Note 5.6K pullup resister on data lines.
//Device is 3 volt was tested at 5 volts no level shifting.
//Reference claims 6 volts is pin max.

//Modified from // TWI (I2C) sketch to communicate with the LIS3LV02DQ accelerometer
//http://www.nearfuturelaboratory.com/2007/01/11/arduino-and-twi/
//Modified code from http://research.techkwondo.com/blog/julian/279
//Thanks Julian.

// Using the Wire library (created by Nicholas Zambetti)
// http://wiring.org.co/reference/libraries/Wire/index.html
// On the Arduino board, Analog In 4 is SDA, Analog In 5 is SCL
// These correspond to pin 27 (PC4/ADC4/SDA) and pin 28 (PC5/ADC5/SCL) on the Atmega8
// The Wire class handles the TWI transactions, abstracting the nitty-gritty to make
// prototyping easy.
 
void setup()

{
 
  Wire.begin(); // join i2c bus (address optional for master)
  Serial.begin(57600);
 
  Serial.println("Wire.begin");
  
  Wire.beginTransmission(i2cID);
  Wire.send(0x21); // CTRL_REG2 (21h)
  Wire.send(B01000000);
  //SPI 4/3 wire
  //1=ReBoot - reset chip defaults
  //n/a
  //filter off/on
  //filter for freefall 2
  //filter for freefall 1
  //filter freq MSB
  //filter freq LSB - Hipass filter (at 400hz) 00=8hz, 01=4hz, 10=2hz, 11=1hz (lower by 4x if sample rate is 100hz)   
  Wire.endTransmission();

  Wire.beginTransmission(i2cID);
  Wire.send(0x20); // CTRL_REG1 (20h)
  Wire.send(B01000111);
  //sample rate 100/400hz
  //power off/on
  //2g/8g
  //self test
  //self test
  //z enable
  //y enable
  //x enable
  Wire.endTransmission();

}

void loop()
{

#define outXhigh 0x29
#define outYhigh 0x2B
#define outZhigh 0x2D
#define statusReg 0x27

boolean goodRead;
goodRead = false;

//----------Status Register-----------------------
  byte status;
  status = B00000000;
  //

//-------------------------------
  Wire.beginTransmission(i2cID);
  Wire.send(statusReg);
  Wire.endTransmission();
   
  Wire.requestFrom(i2cID, 1);
  if(Wire.available())
 {
   status = Wire.receive();
 }



//----------X Values-----------------------
  byte x_val;

//-------------------------------
  Wire.beginTransmission(i2cID);
  Wire.send(outXhigh);
  Wire.endTransmission();
   
Wire.requestFrom(i2cID, 1);
if(Wire.available())
 {
   x_val = Wire.receive();
 }


//----------Y Values-----------------------
  byte y_val;

//-------------------------------
  Wire.beginTransmission(i2cID);
  Wire.send(outYhigh);
  Wire.endTransmission();
   
Wire.requestFrom(i2cID, 1);
if(Wire.available())
 {
   y_val = Wire.receive();
 }
 
 //----------Z Values-----------------------
  byte z_val;

//-------------------------------
  Wire.beginTransmission(i2cID);
  Wire.send(outZhigh);
  Wire.endTransmission();
   
Wire.requestFrom(i2cID, 1);
if(Wire.available())
 {
   z_val = Wire.receive();
   goodRead=true;
 }
//------------------------------- 
 
 
 if (goodRead==true)
 {

//Serial.print("x_val_l= "); Serial.println(x_val_l, DEC);
//Serial.print("x_val_h= "); Serial.println(x_val_h, DEC);
//Serial.print("x_val= "); Serial.println(x_val, DEC);

//Serial.print("y_val_l= "); Serial.println(y_val_l, DEC);
//Serial.print("y_val_h= "); Serial.println(y_val_h, DEC);
//Serial.print("y_val= "); Serial.println(y_val, DEC);

//Serial.print("z_val_l= "); Serial.println(z_val_l, DEC);
//Serial.print("z_val_h= "); Serial.println(z_val_h, DEC);
Serial.print("status "); Serial.println(status, BIN); 
Serial.print(" val= "); Serial.print(x_val, DEC); 
Serial.print(":"); Serial.print(y_val, DEC); 
Serial.print(":"); Serial.println(z_val, DEC);
 }
 else
Serial.print("no data");
 
  delay(100);
}