Hello,
I am a beginner and want to use 8 Servos (Miuzei 9g with 4,8V to 6V) with my Arduino Mega 2560 R3 for a school project. Is it possible or how is it possible? I have a 11,1V LiPo battery for powering the motor as well. To be able to use the battery for the servos i have voltage regulators (7805). They should bring it to 5V, but whatever I do it won't work.
I would be very happy if some of you have a sollution.
Thank you.
@benjaehk, your topic was moved to a more suitable location on the forum.
It is perfectly possible.You will need some code. And some connections. And a much better 5V supply. Each servos may take a maximum of 650mA, 8 x 650mA is way more than a 7805 can supply (unless you have a 7805 for each servo). Much better would be a 5V DC-DC converter, preferably with around 5A.
Please post a schematic showing how everything is connected and your code. Also explain what it is supposed to do and what "it won't work" means in detail.
Steve
Thanks for your help. I actually have a 7805 for each servo. It is supposed to control 8 flaps on a drone, each flap with one servo. The code is programmed by a classmate, I can put it at the end of my message. For testing the power supply I tried to power at first only one servo with the LiPo battery and a 7805. But I used the Servo Sweep Sketch from Arduino for testing. In this case the servo either does nothing or quivers. I tried to make the circuitplan on the internet with my computer, but did not succeed. So i made a handwritten plan. I hope it is ok.
Picture:
The code for 8 servos:
#include <Servo.h>
#include <ServoInput.h>
Servo servoL1; // Define our Servo
Servo servoL2;
Servo servoL3;
Servo servoL4;
Servo servoR1;
Servo servoR2;
Servo servoR3;
Servo servoR4;
ServoInputPin<2> elev;
ServoInputPin<3> aile;
ServoInputPin<18> throttle;
ServoInputPin<19> rudder;
void setup()
{
elev.setRange(970, 1760);
aile.setRange(1100, 1900);
throttle.setRange(1150,1900);
rudder.setRange(1100,1900);
servoL1.attach(4); // servo on digital pin 10
servoL2.attach(5);
servoL3.attach(6);
servoL4.attach(7);
servoR1.attach(8);
servoR2.attach(9);
servoR3.attach(10);
servoR4.attach(11);
}
void loop()
{
float angle_elev = elev.getAngle(); // get angle of servo (0 - 180)
float angle_aile = aile.getAngle(); // get angle of servo (0 - 180)
float angle_rudder = rudder.getAngle();
float angle_throttle = throttle.getAngle();
Serial.begin(115200);
if (angle_rudder> 93 || angle_rudder < 87)
{
servoL1.write(angle_rudder);
servoL2.write(angle_rudder);
servoL3.write(angle_rudder);
servoL4.write(angle_rudder);
servoR1.write(angle_rudder);
servoR2.write(angle_rudder);
servoR3.write(angle_rudder);
servoR4.write(angle_rudder);
delay(5);
}else {
//Vorne und Hinten
float Elev_gespiegelt = 90 - angle_elev;
Elev_gespiegelt= 90 + Elev_gespiegelt;
servoL2.write(angle_elev);
servoL3.write(angle_elev);
servoR2.write(Elev_gespiegelt);
servoR3.write(Elev_gespiegelt);
// Links u. Rechts
float Aile_gespiegelt = 90 - angle_aile;
Aile_gespiegelt= 90 + Aile_gespiegelt;
servoL4.write(angle_aile);
servoR4.write(angle_aile);
servoL1.write( Aile_gespiegelt);
servoR1.write( Aile_gespiegelt);
delay(5);
}
}
The easier you make it to read and copy your code the more likely it is that you will get help
Please follow the advice given in the link below when posting code , use code tags and post the code here
What is the purpose of the ServoInput library and where did you get it ?
#include <Servo.h>
#include <ServoInput.h>
Servo servoL1; // Define our Servo
Servo servoL2;
Servo servoL3;
Servo servoL4;
Servo servoR1;
Servo servoR2;
Servo servoR3;
Servo servoR4;
ServoInputPin<2> elev;
ServoInputPin<3> aile;
ServoInputPin<18> throttle;
ServoInputPin<19> rudder;
void setup()
{
elev.setRange(970, 1760);
aile.setRange(1100, 1900);
throttle.setRange(1150, 1900);
rudder.setRange(1100, 1900);
servoL1.attach(4); // servo on digital pin 10
servoL2.attach(5);
servoL3.attach(6);
servoL4.attach(7);
servoR1.attach(8);
servoR2.attach(9);
servoR3.attach(10);
servoR4.attach(11);
}
void loop()
{
float angle_elev = elev.getAngle(); // get angle of servo (0 - 180)
float angle_aile = aile.getAngle(); // get angle of servo (0 - 180)
float angle_rudder = rudder.getAngle();
float angle_throttle = throttle.getAngle();
Serial.begin(115200);
if (angle_rudder > 93 || angle_rudder < 87)
{
servoL1.write(angle_rudder);
servoL2.write(angle_rudder);
servoL3.write(angle_rudder);
servoL4.write(angle_rudder);
servoR1.write(angle_rudder);
servoR2.write(angle_rudder);
servoR3.write(angle_rudder);
servoR4.write(angle_rudder);
delay(5);
} else {
//Vorne und Hinten
float Elev_gespiegelt = 90 - angle_elev;
Elev_gespiegelt = 90 + Elev_gespiegelt;
servoL2.write(angle_elev);
servoL3.write(angle_elev);
servoR2.write(Elev_gespiegelt);
servoR3.write(Elev_gespiegelt);
// Links u. Rechts
float Aile_gespiegelt = 90 - angle_aile;
Aile_gespiegelt = 90 + Aile_gespiegelt;
servoL4.write(angle_aile);
servoR4.write(angle_aile);
servoL1.write( Aile_gespiegelt);
servoR1.write( Aile_gespiegelt);
delay(5);
}
}
My classmate, who wrote the code, tested the code and it worked. I don't know what the ServoInput library is for, but i asked him and now I wait for his answer (I will write again when I have an answer). The problem that I try to solve is the power supply for the servos with the LiPo battery.
The library looks like all it does is to allow you to determine the position most recently written to the servo. If that is the case then why not use the Servo library read() function ?
Go back to basics and try the Sweep example with 1 servo again. It is not present in your circuit drawing but do the servos and Arduino have a common GND connection ?
You picture is missing the connection between battery/servo -ve and Arduino Gnd and also the necessary capacitors on the 7805.
Steve
I added a GND connection between the servo and the arduino and it works. Thank you very very much, I tried it for 5 hours now and grilled two voltage regulators and one servo. But it works now. Thanks a lot
Hi,
You need to add to EACH LM7805 some capacitors at the IC leads, this helps voltage stability and noise.
Tom... 
PS, The capacitors are required at ALL TIMES, due to the varied manufacturers and quality.
Today I found a new problem. The servos are getting powered by the LiPo, so I added more and more servos. After I added the fourth servo, they started quivering. If I connected the most quivering servo with a voltage messuring device they all stopped quivering and moved as supposed to. Now I'm not sure if I need some capcitors or something else (for example resistances). I searched on the internet, how the messuring device works and it seems to have an inbuild resistance.
Do you still have a 7805 for each servo? Does each 7805 have the 2 capacitors it needs? What is the specification of the LiPo (voltage, capacity and C-rating)? How is everything connected together (NOTE - through a breadboard is the wrong answer!).
Steve
Hi,
Can you please post a picture of your project ,so we can see your component layout?
Thanks... Tom..
No I don't have any capacitators. I will order some, if they are necessary.
voltage: 11,1V; capacity: 2250mAh; C-rating: 25C
Ah right, thank you. I tried to achieve better visibility for the picture and therefore stretched it 
When I saw the problem the cable was connected right.
The Servos still quiver. I think I need the capacitors but I don't know, which specifications they need. Is the stated voltage in the product describtion the maximum of voltage he can sustain or is it his voltage output?
Hi,
Do you have a DMM?
Tom...
