Let's Make Robots!


learning code ... the ups and downs

Thought id post this example to show what im going through in the learning and understanding prossess of coding. For the most part it is very frustrating ... i would have very limited understandig at the moment and practically new to coding have tried before but stopped as other things came up.

But have started again and finding it hard going ... but am having some success ..

Number one reason is not being able to find any site with a teaching process .... have found some great sites that show very good tutorials eg tronixstuff ... 

Good Pan/Tilt Code (Code example included)

I recently did a small consulting gig and built a one-off robot for a customer. The gig included the hardware but also the client needed some example code to get himself up and running a bit quicker. This turned out to be a great oportunity for me to sit down and clean-up some code that I have been using for years, in this case, my pan and tilt code...

       Hello LMR, this is Penny the 3 servo hexapod. Penny is not just a very cheap way to build a hexapod but a very cheap way to build a robot, period. I … Read more

Arduino Code Troubleshooting - VEX Transmitter / Receiver

I'm trying to read the signals sent from the VEX transmitter to the VEX receiver through my Arduino Mega. I started with this code and then made some modifications to visualize the outputs.

arduino code

im working on the ankle servos, so im just using the example sweep, an i have them zeroed at 90 deg. I can get it from 90 to 180 an back but i cant get it to go 90 - 0.   




#include <Servo.h> 


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



int pos = 90;   


void setup() 




void loop() 

beginer in electronics needs to program

hi, im a twelve year old boy who is not an expert  AT ALL, but knows the basics

i've made bristlebots, speaker tones, dc motor cars  and other stuff


when i have to program  in arduino UNO i just copy other codes from other people

cause...  I dont know how to program at all!!!! i think arduino's language is c,and i don't know  how to program


anybody knows how to program arduino

and can give me a little tutorial about key words and etcetera like setup, delay, control of dc motors sensor etc...

Trying to use a light sensor to control a stepper motor

So this code finally works, how do i change it from a light sensor to infrared sensor?

int dirPin = 8;

int stepperPin = 7;


void setup() {


  pinMode(dirPin, OUTPUT);

  pinMode(stepperPin, OUTPUT);

  pinMode(A0, INPUT);


void step(boolean dir,int steps){



  for(int i=0;i<steps;i++)


    digitalWrite(stepperPin, HIGH);


How to contol servo speed from serial

Hello all

I have  renbotics ServoShield and I have made a code on arduino where from serialport I can send commads to servos and it happens with that way... S01P1200,S14P2300etc..I mean that  Servo 1 to 1200 posion and servo 14 to 2300 posion

RF Link Help

I have been expiramenting with some RF links (tutorial here, RF link). The tutorial is great, but it only does serial communications. 

The code I use is 


// transmitter.pde


// Simple example of how to use VirtualWire to transmit messages

// Implements a simplex (one-way) transmitter with an TX-C1 module


// See VirtualWire.h for detailed API docs

// Author: Mike McCauley (mikem@open.com.au)

// Copyright (C) 2008 Mike McCauley

Need to find code for msp430 launchpad

this is my fisrt time using launchpad but I've used others microcontrollers before as pic16, pic18, or arduino.

I'm trying to read data from an ultrasonic sensor ping parallax and see it on the computer using USB and also I want to send it using SPI to a transceiver nordic nrf24l01 and in the other transceiver I allready got an arduino.

The full project is a quadcopter that read the distance when it is close to the ground and also I want to use automatic control to keep it in an specific distance no mather what, thanks for the help.

programming arduino

So I made my first attempt at a robot using my Arduino...

It can be seen here, so that I don't have to explain how everything works again: http://letsmakerobots.com/node/31357

Now my problems is the code. What I have so far looks like so:



#include <IRremote.h>

#include <Servo.h> 


Servo run; // servo for running hind wheels, continuous rotation 

Servo steer; // Servo for steering

int pos = 0;

int RECV_PIN = 11; // IR pin


How to code this properly .....

Ok being distracted from my robot hack of late .... anyway being trying out the led tutorials on tronixstuff and have a little problem ...


Those of you that follow tronixstuff will have seen the tutorials on leds  ... im trying them out at the moment.  First tutorial is http://tronixstuff.wordpress.com/2010/04/04/getting-started-with-arduino-chapter-zero/

Video of problem at bottom of post

Error coming up in code

copied this code from http://www.jeremyblum.com/2011/07/31/tutorial-13-for-arduino-liquid-crystal-displays/ but when i try to compile i get a error at void set up {}( function definition dose not declare parameters) i highlighted the part that gets this error ... but i can figure out whats wrong ...



*RS: Pin 2

*EN: Pin 3

*D4: Pin 4

*D5: Pin 5

*D6: Pin 6

Why won't it vark?

I've made a development bot named Arcee as some of you know, now i've added an AmandaLDR to it for obstacle avoiding.The LEDs on the sensor are very bright and blue in colour. The bot won't use a servo to pan the sensor, it'll simply rotate itself.

The problem is, I don't think it's working. But the sensor works, oddly enough. It can turn an LED on at a threshold. But once implemented into an obstacle avoidance code it dosen't seem to work.

The code is attached below.



Arduino to processing

So I have a Sharp IR sensor connected to my Arduino, feeding to my pc the values of its analog input, via the Serial connection.

To do this, I'm using the Serial.write() command. I want to be able to read these values into processing, but when I use the Serial.read() command in Processing, the values it picks up are nothing like what the Arduino Serial monitor is giving me, and are unaffected by the IR sensor.

What am I doing wrong, and how can I get processing to read these values from the IR sensor?

Any help is appreciated.

IR RC code problems...



#include <IRremote.h>

#define m1F 6

#define m1R 7

#define m2F 5

#define m2R 8


long F = 1979994096;

long L = 1979994056;

long R = 1979994048;

long B = 1979994076;

long S = 1979994080;

int RECV_PIN = 4;


IRrecv irrecv(RECV_PIN);


decode_results results;


void setup()


  pinMode(13, OUTPUT);

  pinMode(m1F, OUTPUT);

  pinMode(m1R, OUTPUT);

  pinMode(m2F, OUTPUT);

Servo coding (solved)

It is working now, thanks to everyone who helped me out!!!



I am trying to make my servo work,but if I start my arduino, with code and servo attached, it just goes to one position and stays there twitching. Can someone help me?

second try

My first hand written code.

I have just written my first code in Arduino IDE. The code should make a servo move to 180 degrees wait one second and then move back to 0 degrees and repeat.

Here it is :


#include <Servo.h>


Servo servo1;

int posR = 179;

int posL = 0;


void setup()





void loop()







sensor jitter problems? Let's fight back.

I wrote a tiny function in Arduino-C for my sensor-jitter problems. You can smooth out your sensor readings with this little function. You can input the smoothness and then get back the smoothed sensor value.

If somebody needs it - here it is:

// Jan Przybilla, Rosk, Farbtonstudio.de
// SSR - Smooth Sensor Readings
// Fight the (((Jitter)))!

Saves time and avoids many related coding mistakes.
I have been learning about programming for years. More recently, I have been taught that magic numbers or constants should not be hard coded deep in your program. … Read more

Area mapping

I have (that is relative because I have not yet ordered my first parts from Robotshop) a PING ultrasonic sensor. I'll be having an arduino mini - though I'll no doubt buy something bigger after - and I wonder if I can efficiently make my upcoming rover (differentially driven, nothing special really) map it's surrounding area using a grid. Is it possible or will I run short on memory with the arduino mini? And more importantly, I need help with the code (I have 0 experience with code, though I have enough theory I guess...). Any suggestions are appreciated.

Picaxe code

Hi all,

I've been busy over the past few days studying the Picaxe manuals and trying to understand the coding. I keep reading about how easy it is and it's even called basic, but my problem is, I don't understand any of it.

My electrical and mechanical skills are enough to get me by, but this programming makes no sense to me what so ever.

I've Googled in an attemp to find online tutorials, that doesn't seem to help either.

Can anyone explain how they learned the Picaxe basic coding? That might help me.


The Bromz.

Homebrew tilt compensation?

Honeywell's datasheet on the HMC6343 compass states that tilt compensation is made using data from a built-in three axis accelerometer. I thought that a cheaper three-axis magnetometer- accelerometer combination is much more reasonable for small scale projects, so my question is: What kind of calculations do I need to perform to get a decent degree of accuracy?


Doubts about software development for robots

Hi LMRtians

After doing some programming for my first robot I was wondering (maybe because of my computer science background) if someone uses some kind of notation or software development methods at the hour of programming the robot.
When you are programming simple things like the Start Here Robot (http://letsmakerobots.com/start) it is easy to program a sequence of actions:

  Condition 1: gosub Action 1
  Condition 2: gosub Action 2

Listen to LMR!

I came across a website called www.codeorgan.com that turns the code of any website into music! put the url for the LMR homepage in, and it sounds pretty good. I wouldn't expect less from LMR.

Stupid / Beginning Questions

I'm somewhat new to arduino and finally found out about libraries.  Unfortunately I have looked for instructions on how to create one and how to upload an existing library.  So if someone could give me step-by-step instructions on how to get this library i have here sitting on my desktop to something i can use in code. (please dummy-down the instructions).

It would also be helpful if someone could provide me with a small sample code for a robot that uses Ping)))

Code Repository!

Can we get everyone who has got their code to successfully run to post their files here? Ive been looking all over the site for a central area for code, and I cannot find one. If there is one, point me in that direction, if not, lets all start posting here!

Try not to paste lines of code here, lets keep it clean. uploaded files only please!


Name of code,

What it's for

File (zip or IDE compatible file)


What do you guys think?

Arduino Motor Control Code Help

I am currently using a arduino duemilanove, and it is awesome. I have been playing around with it for a couple of days now, and I really like it. Anyways I figured it was time to start to building a robot. I decided to start with the motors. For the motor control I decided to use guibot's tutorial. It worked fine, but the motors only traveled in one direction. Because I wanted the motors to also travel in reverse too I decided to experiment with my own code (on only one motor) that looks something like this: