SG90 wont work

Other Hardware Motors, Mechanics, Power and CNC
1

Hi guys,
I've got this servo in my robotic arm, before as i checked it without construction of a robot it worked, but now, it won't. i've update to Ardu the sweep example, nothing happens, i've checked him with myservo.read() and he's always 93 degree.

i've wired it up correctly, red to 5.7V, brown 0v and orange to Ardu. Ardu and my generator have bridged 0v.

i've also tried to attach it to differend pins, and tell him to move by myservo.write() myservwo.slowmove() and myservo.writeMicroseconds(). Nothing works

Also servo after attaching haven't any resistance to move it, i can just move it without any problems <Ampers didnt rise when i'm moving it>

All other servos are working, like 2x SG-5010 or M160mg

Thank for Your guidance,

2

circuit? code?

But first two things to check:

supply for servo can provide at least 1A?
grounds are commoned between servo and Arduino?

3 

#include <Servo.h>

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position

void setup() {
  myservo.attach(4);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
}

Yeap, i Have generator which can handle max 5 Amps and 60V
As i said, other servos are working, but this SG90 won't, before, smth like day ago it worked...

4

Code does not reflect schematic.

5

i said, that i've attached to all of pins, if i've write
servo.attach(7) i wired up signal wire to 7 pin etc. etc. but i'll change it

6

Yeap, i Have generator which can handle max 5 Amps and 60V

Did you adjust this "generator" voltage or amperage while trying to make this robotic arm work?

7

Yeah, from 5 to 6.5 V and Amps about 2.5A for all servo. Now i have 5.6V and 2.5A. its enough, while all of them are moving they didnt take more than 1A.

Dont think its a faulty servo, because before it worked perfectly.

Maybe should i check voltage inside servo?

8

Start off with a basic test such as the "Sweep" although I like to use the "Knob" example because it allows one to play with the angle of the servo (also good for arming an ESC).

Plug in a good servo to see it work then try your bad servo.

Maybe the wires got a little wiggled to much and you have a bad connection inside the servo.

See if wiggling them causes the servo to respond.

9

Tested with knob and sweep, another servo like SG-5010 works, faulty one didn't. Wiggling also didn't help.

10

Ever seen the inside of a servo? Good time now.

11

Okay. I checked the servo inside. Connections from microcontroller was good. But. I saw a scratch on microcontroller. Dont know if u Can spot it on this pic, but i think this scratch was caused with some error with microcontroller, and higher current than expected, is my thinking good? Or it could be something else?

microcontr.png
microcontr.png484×645 470 KB