arduino - Servo delay on direction change -


i'm using sg-90 servo , sweeping left , right between 2 values. problem there distinct delay of 500ms between direction changes. position of servo predictable, due @ direction changes not.

bool servodir = true; int servocnt = 90; int servoinc = 1; int servomin = servocnt - 5; int servomax = servocnt + 5;  void loop() {     if (servodir) {       dx = servoinc;       if (servocnt > servomax) {         servodir = false;       }     } else {       dx = -servoinc;       if (servocnt < servomin) {         servodir = true;       }     }     servocnt += dx;     servo.write(servocnt);     // delay or other code here (mine 40ms) }

i've tried both arduino servo library , varspeedservo library. both show same thing.

what cause of , can it?

update

so if speed @ direction change, so:

int = 5; void loop() {     if (servodir) {       dx = servoinc;       if (servocnt > servomax) {         dx -= extra;         servodir = false;       }     } else {       dx = -servoinc;       if (servocnt < servomin) {         dx += extra;         servodir = true;       }     }     servocnt += dx;     servo.write(servocnt);     // delay or other code here (mine 40ms) }

the delay disappears, servo position become lot less predictable.

you experience these symptoms if servomin , servomax out of servo range.... are.

more seriously, these servos not precise. incrementing 1 @ time issue. experiencing form of backlash.

you should check , clamp count against range after incrementing/decrementing. that's 1 of basic rules of embedded programming. lives may @ stake, or equipment destroyed when sending out out of range values.

bool servodir = true; int servocnt = 90; int servoinc = 1;             // <-- exclusively use control speed. int servomin = servocnt - 5;  // <-- range bit short testing int servomax = servocnt + 5;  void loop() {      // 'jog' servo.     servocnt += (servodir) ? servoinc : -servoinc;      // past point, position jogging final     if (servocnt > servomax)      {         servocnt = servomax;         servodir = false;     }     else if (servocnt < servomin)      {         servocnt = servomin;         servodir = true;     }      servo.write(servocnt);      // 40ms sounds bit short tests.     // 100 ms should give 2 seconds (0.5hz) oscillation     delay(100); }

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