DATA_READY interrupt is always high and is not toggling, tested using a multimeter.
according to the datasheet the flag is cleared each time the data is read, as it was not working I tried reading to INT_SOURCE register to clear it myself and it didn’t change the outcome.
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_ADXL345_U.h>
#include <avr/io.h>
#include <avr/power.h>
#define F_CPU 16000000UL
int state=0; //0--active detecting; 1--sleeping
int state_count=0; //sleeping trigger between 2 states
double mag[40];
int i=0;
double acc_rate[39];
int hunt_sub=0;
int exit_marker=-10,trough_marker=-30,peak_marker=-10;
volatile int sensor_update=0;
byte buff[1] ;
volatile unsigned long time=0, time0=0,time_dis=0,time_array[40]={0};
//----------------------------------------------------------------------------------------------
//Read ADXL345 registers
void readFrom(int device, 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 (initiate again)
Wire.requestFrom(device, num); // request 1 byte from device
int i = 0;
while(Wire.available()) //device may send less than requested (abnormal)
{
buff[i] = Wire.read(); // receive a byte
i++;
}
Wire.endTransmission(); //end transmission
}
//Write to ADXL345 registers
void writeTo(int device, 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
}
//----------------------------------------------------------------------------------------------
/////////////////////////////////////////////////////////////////////////////////////////////
//ISR function
void interrupt(void){
sensor_update=1;
// time0 = time;
// time= millis();
// time_dis=time-time0;
// if(i<40){
// time_array[i]=time_dis;
// }
readFrom(0x53, 0x30, 1, buff); //clear interrupt
}
void buzz(int targetPin, long frequency, long length) {
long delayValue = 1000000/frequency/2; // calculate the delay value between transitions
//// 1 second's worth of microseconds, divided by the frequency, then split in half since
//// there are two phases to each cycle
long numCycles = frequency * length/ 1000; // calculate the number of cycles for proper timing
//// multiply frequency, which is really cycles per second, by the number of seconds to
//// get the total number of cycles to produce
for (long i=0; i < numCycles; i++){ // for the calculated length of time...
digitalWrite(targetPin,HIGH); // write the buzzer pin high to push out the diaphram
delayMicroseconds(delayValue); // wait for the calculated delay value
digitalWrite(targetPin,LOW); // write the buzzer pin low to pull back the diaphram
delayMicroseconds(delayValue); // wait againf or the calculated delay value
}
}
/* Assign a unique ID to this sensor at the same time */
Adafruit_ADXL345_Unified accel = Adafruit_ADXL345_Unified(12345);
void setup(void)
{
if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
//Serial.begin(9600);
//Serial.println("Accelerometer Test"); Serial.println("");
pinMode(4, OUTPUT);// buzzer output pin
//pinMode(2, INPUT);
/* Initialise the sensor */
if(!accel.begin())
{
/* There was a problem detecting the ADXL345 ... check your connections */
//Serial.println("Ooops, no ADXL345 detected ... Check your wiring!");
while(1);
}
/* Set the range to whatever is appropriate for your project */
accel.setRange(ADXL345_RANGE_16_G);
accel.setDataRate(ADXL345_DATARATE_1_56_HZ);
// displaySetRange(ADXL345_RANGE_8_G);
// displaySetRange(ADXL345_RANGE_4_G);
// displaySetRange(ADXL345_RANGE_2_G);
/* Display some basic information on this sensor */
//displaySensorDetails();
/* Display additional settings (outside the scope of sensor_t) */
//displayDataRate();
//displayRange();
//Serial.println("");
//Create an interrupt that will trigger when a tap is detected.
writeTo(0x1D, 0x2E, 0);// disable interrupt
attachInterrupt(0, interrupt, RISING);
writeTo(0x53, 0x2F, 0); //map data_ready to INT1
writeTo(0x53, 0x2E, 128); //enable data_ready
}
void loop(void)
{
sensors_event_t event;
accel.getEvent(&event);
mag_calculation (event.acceleration.x, event.acceleration.y, event.acceleration.z);
if(sensor_update==1 ){
//When sensor_update is set to 1 in the ISR,the algorithm process the data from the accelerometer being updated every 10ms(100Hz)
//rest of algorithm is here
sensor_update=0;//reset
}
}