Let's Make Robots!


Servo powering problem

Hi guys, me and my friend have built an arduino controlled Quadruped "mantis" robot.

Video tutorial on wireless XBee serial with the Due and DynamixShield

I just uploaded a new video tutorial on how to perform wireless communications using Grove XBee sockets with two Arduino Dues and the DynamixShield. This is part of my Kickstarter campaign to get the DynamixShield produced commercially. It lets you control smart and regular servos, and has tons of Grove and RobotGeek connectors, all in one shield.

Trouble with servos!

I’m working on a robot that’s supposed to place dominoes in a track. As part of the design, there’s an arm that grabs and places the dominoes.

Humanoid concept Arduino

This concept to make a humanoid head, that speaks like a human, chooses phrases randomly. As (it) speaks , it moves head, eyeballs and eyebrows randomly in an emulation of a human. This can be useful for lonely people who cannot have a pet at home.

This is the basic idea..Later it is possible to develope it further to talk longer durations, and even tell short stories stored on an SD card.

help needed. looking for somone local to Phx, AZ - 2 servo's, controlled via wifi

i'm trying to develop a device that is controlled with 2 servo's. i want the servos to be controlled independently over wifi with either a joystick or c# application. i have the project started with the following. i am looking for someone to help me complete this project, 

c# applications

Audrino uno

cc3300 wifi shield

Audrino 1.0.5-r2 sketch pad

2 Futaba s3305 servo's

DC 5V Stepper Motor 28BYJ-48 + ULN2003 Driver Test Module Board for Arduino



Motor control or servo control


I came across this circuit on google. It controls motor speed by simple flip-flop that gives a PWM signal.

The question is can this be used as a servo control ?

first use 5 volts supply instead of 12 volts ...then by replacing the 3RD NPN transistor with a servo. the + goes up, the - goes down and the signal feeds from the flip flop...can we do that ??

Trying to encapsulate a servo instance, no movement

Hi there,

I'm having an issue with encapsulating servo functionality in its own class. What I want to do is creating a class that contains a couple of methods that control a servo more or less autonomously, in such a way that just requires me to set the context and then in the loop calling myservo.update() to have the myservo class take care off its own. Very OOP indeed :-)

For some reason I just can't get it to work. Brought down to the bare minimum, I have three source files, main.ino (off course), myservo.h and myservo.cpp:

myservo.h contains this:

Dagu Robotic Arm 6DoF - Bacuri02 Project

I recently received my Dagu Robotic Arm 6 DOF with Arexx control board 32 servos.

My original project is to use an Arduino Mega to control the arm and then make a wifi connection joystick control.

As I have not received my Arduino Mega board, I started tinkering in Arexx control board that I received along with the robotic arm. Along with the kit also came with a CD ROM which I believed the program to be installed on the computer to control the arm.

Biped Howto: Moving servos

+++ UPDATE (12-march-2014): Rename title as "Biped Howto".

Hi, I will try to explain, in a very simplistic manner, the way in which servo motors can be controlled.

Servo motors are controlled by a PWM signal, in which the active part of the signal (known as duty cycle) define the amount of degrees the servo will rotate.

raspberry pi arduino,

So im pretty newish to robotics and programming in general, but ive done some reading and have started down my own path.

my robot(including a picture, description, wiring diagram and code) is posted here http://letsmakerobots.com/node/40350

Starter Robot Question

Howdy! I've been working on my "Start here" robot. I've not yet got a distance sensor (I am instead using a light sensor to take two readings moments apart, generate random numbers from them, and then compare those two so as to travel at random.) I do have a servo, but I have been enjoying having it play sounds through a speaker. Now, that being said, I'd like to hook up the servo, but A.) don't have the 330r DIL chip, and B) don't want to take out the darlington. 

Arduino Servo library and softwareserial library conflict


I need some help for this.

I am using arduino UNO and i have connected a GPS to softserial and a servo to pin9 and when the software runs the servo and softserial fights. I check online about the issue and it happend to many people and still i am unable to get a solution for. 

I even tried almost all combinations of solution from internet and it did not work. When this happening some times servo works and other times GPS works. 

hope to get some support

Robot Servos/control board advice

Hi, I would like to do an investment and to buy some servos (10/20 units).

I don't have too much money to spend, so I'm looking for cheap servos with however enough torque to do some interesting robots (humanoid, arm, hexapod, etc).

Initially I found MG995/MG996R servos, then I found rds3115 robot servo.

The features of the rds3115 are:

modified servo .. continious rotation problem

Hi all ... have a little problem with a servo i modified for continous rotation 

#include <Servo.h> 

  Servo myservo;  // create servo object to control a servo 

  void setup() 

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object 

  void loop() 

Few questions about Spider Controller (DAGU)

Hello all!

I'm newbie and I have few questions about Spider Controller (from DAGU).

1) When USB is plugged and the battery is plugged too - which source of power controller will be use for servos?

2) As i understand, If i use analog servos I should plug it to PWM-outputs. And digitall servo can be plugged to any output. Am i right?

3) Can't understand what is the role of ON/OFF switcher. It is for battery only?


Many thanks in advance.

Looking for ideas on a I2C Pan/tilt stand-alone sonar

This quest to build a stand-alone I2C pan/tilt range finder controller started with an article here by Ladvien.  In    http://letsmakerobots.com/node/39130, Ladvien explores using an ATtiny85 (84) as an I2C motor controller...

And in http://letsmakerobots.com/node/39222,   Chris the Carpenter   gives us an awesome pan and tilt code example... so...

PICAXE28x1, Sharp IR Sensor and Infrared sensor problems

Hi everyone,


I'm making a robot project for my mechatronics course and I am using picaxe28x1 with an infrared range sensor that I just copied from the Start Here post here at LMR. I did everything, and exactly the same set up like what the guy did. Howeve because we are required to make at least one of our own infrared circuit, I added an infrared sensor (with a transmitter and receiver circuit and a LED indicator) circuit together with the servo and the Sharp IR sensor. I did the set up and wrote my program but it's not doing the job.

So this guy happened last night. I have been inspired by the work of Mr. Protowrxs and his Box Head Robot and thought I needed a little deskbot as well. I also … Read more

Help requested with programming "Official Arduino Robot".

I need some help programming a servo routine for the new "Official Arduino Robot".

So far, NONE of the standard Arduino servo routines function with this robot. "#include <Servo.h>" is the most common servo control routine and I get an "Error 17" whenever I attempt to use it.

More recent "standard" servo routines refuse to function as well.

It was a big shock that the robot included no servo control in its list of functions. "Forget something, Arduino???" :-)

Any help would be GREATLY appreciated!

PROJECT CONTINUED! So I found a motor from a toy. Works fine. The same speed as the other. But I still have the problem with the whole robot turning. I'll post a … Read more

6 wire RC steering servo?

Hi All!

This is my first post so go easy on me. :)

I am trying to build an obstical avoidance robot and decide to salvage a chasis from an old Radio Shack RC truck. The main board is fried. when I got to the se=teering mechanism I discovered 6 wires coming form what I would think is a servo. I was expecting three wires so I'm not sure how to hook it up to my motor shield for an arduino.

I discovered that if I applied a voltage to two of the wires the wheels turn on direction and if I reverse them they go the other way.

My PCB's Are Here!!!

Hello everyone my PCB's are here, they were actually meant to make my robot more tidy as shown here (turn off the sound)

Is my servo defect? (fast one way, struggle the other)

I bought a pan/tilt kit from nodna.de, with 2 micro servos...
I hooked them up to my Fez Panda II's PWM and 5V power, then made a simple program to move them  from all the way left to right.

But when i run it, it moves really fast to one side, then it struggles to move the other way, nearly dont move...?
Same problem with both of them... sounds like they dont have the power to turn... ?

Could there be somthing im doing wrong? or are they just simply defect? 


Using Sabertooth 2x12 with motor and servo.


I have an RC car that i've stripped down to it's bare essentials.  It has one motor that provides forward/backward movement and it has a servo that turns the front wheels left/right.   I can use the Sabertooth 2x12 fine with the motor.  The problem is however the servo. 

Now available from PicoKit!http://www.picokit.com - A cheap and simple 3 servo robot walker that anyone can make for under $40. My students in Industrial … Read more

Everything you never wanted to know about two wheel drive.

Platform Drive Control.

This platform is driven by two wheels mounted so that the wheel axis
is just off center. There is a small caster wheel mounted in the 'rear'.

At this time there is no speed control feedback.

Maneuvers are accomplished by independent but coordinated control of
each wheel motor.

The drive motors are servos that have been hacked to continuous rotation.
The servo hack involved pulling the feedback control board and pot as
well as cutting the stop on the main gear. Thus the servos are converted

Need help controlling Traxxas ESC and Servo with Arduino

I'm working on an autonomous ground vehicle, guided by a U-BLOX Neo 6m GPS Module, and HMC5883l compass.

The ESC connects to the 7.2 NiMH Battery pack and is supposed to be connected to a RC receiver with a standard 3 wire servo cable, it also provides 6 volt regulated power from the same cable. Because the power is too high for an Arduino, I used a separate 5 volt power supply for the rest of the electronics, except the steering servo. Using a separate power supply makes the ESC and servo uncontrollable, creating a lot of jitter.