Hello
im using an accelerometer (adadruit MMA8451 ) with an arduino uno and am trying to monitor acceleration of a surface that will move axis its not a fixed location.
essentially i need the sensor to read as if its in free fall with out the effects of gravity on it. as when i have it on my table it reads
x = 0m/s^2 y= 0 m/s^2 z = 9.81m/s^2
the code im using includes references to adafruit MMA8541 EXTERNAL Folder (code shwn below
does anyone know how to get the accelerometer to read m/s^2 without the effects of gravity ie free fall
Thanks very much
heres an image f the serial monitor output
Preformatted text
#include <Wire.h>
#include <Adafruit_MMA8451.h>
#include <Adafruit_Sensor.h>
Adafruit_MMA8451 mma = Adafruit_MMA8451();
void setup(void) {
Serial.begin(9600);
Serial.println("Adafruit MMA8451 test!");
if (! mma.begin()) {
Serial.println("Couldnt start");
while (1);
}
Serial.println("MMA8451 found!");
mma.setRange(MMA8451_RANGE_2_G);
Serial.print("Range = "); Serial.print(2 << mma.getRange());
Serial.println("G");
}
void loop() {
// Read the 'raw' data in 14-bit counts
mma.read();
Serial.print("X:\t"); Serial.print(mma.x);
Serial.print("\tY:\t"); Serial.print(mma.y);
Serial.print("\tZ:\t"); Serial.print(mma.z);
Serial.println();
/* Get a new sensor event */
sensors_event_t event;
mma.getEvent(&event);
/* Display the results (acceleration is measured in m/s^2) */
Serial.print("X: \t"); Serial.print(event.acceleration.x); Serial.print("\t");
Serial.print("Y: \t"); Serial.print(event.acceleration.y); Serial.print("\t");
Serial.print("Z: \t"); Serial.print(event.acceleration.z); Serial.print("\t");
Serial.println("m/s^2 ");
/* Get the orientation of the sensor */
uint8_t o = mma.getOrientation();
switch (o) {
case MMA8451_PL_PUF:
Serial.println("Portrait Up Front");
break;
case MMA8451_PL_PUB:
Serial.println("Portrait Up Back");
break;
case MMA8451_PL_PDF:
Serial.println("Portrait Down Front");
break;
case MMA8451_PL_PDB:
Serial.println("Portrait Down Back");
break;
case MMA8451_PL_LRF:
Serial.println("Landscape Right Front");
break;
case MMA8451_PL_LRB:
Serial.println("Landscape Right Back");
break;
case MMA8451_PL_LLF:
Serial.println("Landscape Left Front");
break;
case MMA8451_PL_LLB:
Serial.println("Landscape Left Back");
break;
}
Serial.println();
delay(500);
}