I have a trouble with following, few lines code. For some reason after few seconds Arduino uno stops responding into void loop section of code. I tried to remove serial communication, all print and println without any success. Is the problem comming from MMA_7455.h?

#include <MMA_7455.h>
#include <Servo.h>

int servoPin = 9;
int servoAngle = 0;

Servo servo;

MMA_7455 accel = MMA_7455();
char yVal;
char yVal_bkp;

void setup() {
    accel.calibrateOffset(1.0, 26.0, -69.0);

void loop() {
    yVal = accel.readAxis('y'); //Read out the 'y' Axis

    if(yVal_bkp != yVal + 2 || yVal_bkp != yVal -2)
        servo.write(90 + yVal);
        yVal_bkp = yVal;

P.S. Servo is normal G90

  • accel.readAxis() returns unsigned char. You are using char which is signed in AVR GCC gcc.gnu.org/wiki/avr-gcc Jul 24 '16 at 10:24
  • Yes, it returns only positive values, I alredy verified, but if you assign this value to char yVal it returns signed value (ex -12) in Serial.print(yVal, DEC); Jul 24 '16 at 10:28

Have you checked that MMA_7455 can handle this many reads?
I had sensors that stop working because I asked to often for feedback.
As the servo needs a 20ms to adjust its location I would add a delay(20) to the loop.

  • Thanks for reply. After delay(20); add, correct execution is going for much more time, but anyway stops after. Increased also to 40, same result... Jul 24 '16 at 15:24

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