Let's Make Robots!


Tells the direction of motion
The device uses 2 ldrs. It is programmed to check if any of them is low(I mean not receiving light). If so, then it checks if now the other one is low. Based on … Read more
Sweeps the floor using ultrasound, IR, and an encoder for obstacle detection/avoidance
Using a
this is a follow-on to an earlier proof-of-concept robot found here: http://letsmakerobots.com/node/36052 The brush part of this sweeper is from a Shark hand held … Read more

Hexapod controlled by arduino+devantechSD21

Hello there,

I am working on a hexapod robot and i am trynig to controll it by using aruino + SD21 servo controller.When i am  test each servo separately ,are acting like i want but when i am connecting all of them its like most servos are not moving at all.


This is my code:

#include <Wire.h>

#define ADDRESS 0xC2  


int servo1  = 63;

int servo2  = 64;

int servo3  = 65;

int servo4  = 66;

int servo5  = 67;

int servo6  = 68;

int servo7  = 69;


Finaly, after years of waiting, the killer app is here: ArduinoDroid an app that allows one to program an Arduino board from a tablet or (some) phone. Yeah, now you can pack light for that robotic contest or conference, no need to carry the whole laptop, just a tiny 7" tablet that you can also use to read, watch movies, play games... or quickly tweak your sumo robot's code.

pushes other bots out of the arena
Using a
Hi everybody, as some people allready know i am new to LMR and robots all together, meaning this is my first robot. It was originally going to be a holiday project … Read more
Autosquared, or automatic automobile, or just A2 is my current testbed for developing GPS code, ultrasonic sensor relilibility, etc in an outdoor enviroment while … Read more

A hexapod for my son to ride on - a big experiment

After seeing the weblink by bdk6 "inspiration for Hexapod builders" I was inspired. The video is of the "Mantis" turbo diesel all terrain hexapod.

Ok, I cannot afford to build a 2 tonne turbo diesel hexapod but I can build one big enough for my 8 year old son Shi Sen to ride on. My plan is to have almost the entire robot laser cut from 6mm plywood.

IR Sensor Info

IR Sensor Info

IR distance sensor - Sharp GP2YOA21YKOF
This sensor has a range of 10cm - 80cm. Approximately 4" - 32".
The sensor outputs an analog voltage based on the object distance. The
voltage ranges from 3v for a near object to .4v for a distant object.

The IR sensor is mounted on a a servo that sits on the rotating base.
This gives both an X and Y axis movement to the IR sensor. The base
rotation will sweep the sensor back and forth, across the width of the

Reversing DC Motor

I have the 4WD Dagu 5 Rover with a Dagu 4 channel motor controller and I have got that working perfectly with an Arduino UNO and it runs very well.

I need to control 2 more DC motors however and so I went and got another motor controller and wired it the same using different outputs from my Arduino. I used very similar code for this DC motor as I did for the 4 wheels of the Rover.

arduino infrared help

Anyone out there successfully used the IR libraries with arduino? Calculon is trying to use it with some bots, but not in the way the libraries are written. Calculon is trying to get one duino to talk to another using a byte, the way that a Picaxe can.

All the code and tutorials he has googled seem to be for emulating or talking to a remote control and figuring out the protocol of that remote.

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

YellowBot, project overview.

The platform should be able to independently navigate our normal household
without getting stuck in/under something or falling down the stairwell.

This project has been down using previously purchased kits and very little
additional hardware. All of this is done using an ArduinoUno.

The platform drive system is a two wheel setup using a frewheeling cater wheel
at the rear.

The platform has been setup with a breadboard and mounting for the Arduino.

The Arduino is powered by a 9v battery.

hexapod control using arduino

i am working on a hexapod controlled by arduino + devantech sd21 servo controller... can anyone send me any working sample code ? so i can see how it works...

Obstacle avoidance via IR sensor.
Using a
My goal is to create an obstacle avoiding mobile platform. I'd like to add a Raspberry Pi to supply remote communitions and some control. The platform should be … Read more
Navigates tight areas and broadcast a video from a mounted IPCam
Glad I found this site.. Although I've been building robots of the LEGO and DIY sort for some time, this is my first post here. Sometimes, robot ideas come to me … Read more
     Hi guys.      One month ago I ordered two $1 webcams from eBay for future projects with some vision functions. Last week I received those items and I … Read more

Dagu 5rover arduino code

Hello i Got the dagu 5 rover and the 4wd motor controller, attached it to an arduino,  i wrote code to use it but it doesn't seem to be functional


volatile int rotaryCount = 0;


#define INTERRUPT0 0  // that is, pin 2

#define INTERRUPT1 1//pin 3


#define DIRECTIONA 4

#define MOTORA 5


#define DIRECTIONB 7

#define MOTORB 6


int QEM [16] = {0,-1,1,2,1,0,2,-1,-1,2,0,1,2,1,-1,0};               // Quadrature Encoder Matrix


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.

arduino error when uploading a sketch

i just got my arduino today and when trying to upload the simple led blink code off the arduino site and an error came up saying "serial port 'com4' is allready in use , try quiting any programs that may be using it.

can anyone tell me how i can deal with this???

uses ultrasound to navigate around obstacles
Using a
I came across the instructions to build this in a magazine and found it a great entry into robotics. It is working well but I'm still fine-tuning the programming. I … Read more
Recently my company has been asked to demonstrate a robot that can perform an enviromentally friendly task. I only have about 1 month to complete the robot and I'm … Read more
Reprogrammable remote for use with all my Arduino bots
Using a pair of APC220’s from Core Electronics, an Arduino Uno and Nano and a SNES controller I made this nifty retro looking reprogrammable controller for all … Read more

Arduino Measuring Time in Milliseconds

Greetings fellow robot builders,

I have used my Arduino so far with much succes but I cannot, for the life of me, find out how to measure the time from one point of the program to another in milliseconds. I have downloaded the Arduino "Time" library and it seems that that can only measure in whole seconds and as many of you know, a second is a very very long time in a program. By the way, I do not want the robot to pause in this time. (I know about the "delay" function)

Any help would be appreciated.

Thanks, Riddellikins

autonomous lawn mower
Using a
Well I have finally made some time this winter to return to my lawn mower project.. This has plagued me for a few years, trying to figure out the buried wire … Read more
Autonomously roaming, avoiding obsticles
Using a
Third robot build, almost identical to RoverBee One. Using the following: - Arduino Uno - Arduino Motor Shield r3 - HC-SR04 Distance Sensor - Tamiya Universal … Read more
Autonomously roaming, avoiding obsticles
Using a
Second robot ever built using the following: - Erector set for chassis. - Arduino Uno - Arduino Motor Shield r3 - HC-SR04 Distance Sensor - Tamiya Twin Motor … Read more

ATtiny servo control


After a brief discussion with fellow LMR member Maxhirez, about his Hedwig robot,
it seems as though there isn't much support for servos in the ATtiny family of
microcontrollers. After fighting with the 8-bit servo library I found HERE that was
supposed to make it as easy as a standard Arduino to add servos to an ATTiny project,