Let's Make Robots!

Direct pin reading/writing instead of digitalRead and digitalWrite

Hi guys, I'm trying to make a bit bang serial connection through mega328 and Arduino seems to lack speed as the connection never happens. Here is the code, so you can better understand what I'm trying to do:

Rf links sending and interpreting

I have made a controller and trying to start programming. This is my first time playing around with rf links. I have went through gareth's walkthrough and get messages to print on my screen, thats cool but what about sending other stuff. My question is must i always send messages or can i just send integers? Also i need a bit of help on how to get the receiving code to interpret the message or integer. 

Arduino Duemilanove and Ardumoto SparkFun Motor Shield help

Hello all... first post on here :)


I am very new to Arduino and coding, for the past few days I have been struggling with some code. I am working towards a small Arduino based rover with two DC motor for movement control. Before I build a body and all that fun stuff I wanted to get basic controls working.

With the code below I can move forward, backward and the BR200# and so on...  (RB case) all work. When I try BF200# nothing happens.. I thought it might be due to the LOW settings on both motors as the HIGH HIGH works ok. 


Problem with SparkFun PicAxe USB programmer cable

Ok, got to the point where it's time to start coding and I got power to everything that needed it and started installing the drivers needed for the Picaxe programmer cable. Well to no avail. If anybody has an idea a walkthrough it would be appreciated.



PIC processors

  I am getting use to Parallax basic stamp and find it easy software to use. Curious about PIC processors. They have many kinds and sizes. I am interestted with as much I?O as possable and imfo on an inexpensive programming board and perhaps a proto board later. The programming language seems similar to me. What is the compairison besides price. I am not a beginner with electronics just programming. Any helpful imfo would be appreciatted. Thanks in advance.

line follower

actually  i am beginner in autonomous bots, i am making a line follower . i wanted to know whether its necessary to give  time delay  while programing the bot. if yes then how can we decide the right amount of time delay??

PolyMorph Hand (Anthropomorphic)

This for sure will be one of my next experiments........

Edit:- ........ Already experimented

Wheeled to Biped conversion

Greetings. *spock sign*

 I have been reading a lot of these articles over a period of time while trying to develop a good understanding of robotics before I begin making them. (It's always a good idea to test the water before jumping into a lake, right?)

Start robot pins

I really hate to ask this question, but what pins do you need to put onto the microcontroller to connect the servo and sensor? I ordered some online that I thought were correct, but they do not fit. I tried going to my local Radioshack to get more, but they sold zero pins. I'm going to order more online, but I would like to ask first to make sure I'm getting the correct items this time.

AXE 045 RGB sensor


 Does anyone around here have any experience with the AXE045 RGB-sensor from Picaxe? I connected it to my Picaxe 28X1 microcontroller and I am only able to get readings from about max 40 for red and blue, green only gets to one or, if I shine directly into the lens with a flashlight, up to 9.

 Any help?




arduino code probs(again)

ok the motor code works fine now, but now i added, some of the 2-10cm infrared sensors ,and the code just drives forward, as if it doesnt see the infrared? any help would be appreciateted ,here is the code

int infra=3;
int value = 0 ;
int infra2=4;
int val2= 0;

void setup()
  pinMode (11,OUTPUT);
  pinMode (10,OUTPUT);
  pinMode (3,INPUT);
  pinMode (infra,INPUT);
NEW: the first 2 parts work the third doesnt 

LCD not quite working

Here is my LCD. http://www.sparkfun.com/commerce/product_info.php?products_id=709. The backlight is working, which isnt much. The problem is that it just isnt displaying the messages. The code is the code in the example and i am very certain it is right. The pins are in the same pins as the code and the example shows. So assuming that this is connected right, i think i may know some of the problem.

Could the 6v i supplied have fried it?

Another capacitor question

I'm working out my understanding of capacitors, I'm a bit stuck on the differences between these 2:

Mono Cap from Jameco


l293d problem

Ok so what does this mean....

 1. the four corner pins are connected to 5v

2. the 2 middle pins on each side of the chip are connect to ground

3. the pins on the outside of the ground pins are connect to the motor

4. the pins on the outside of the motor pins are connected to the inputs.


I have verified those contacts with a multimeter and they are all getting there respective connections and voltages.  

So it is connect correctly.

arduino code not working the way it should

i made a code ,and the code doesnt work the way it should, it makes the motors go bakwards ,pause, backwards

this isnt what i told it to do, why is this so here is the code , hope you can help cause i want to enter this in the arduino challenge

Xbee modules help

HI, well, the free day is arriving, so i thought i'd go to sprakfun and fill my cart.

what exactly do i need to have wireless COM betwen two microcontrolers, or PC, to micro controller, or even stand alone Xbee's?

I have these items in my cart:

Christmas Presents

What was the best present you got this year? post it here so we can all see and show off to others what we got for christmas.

grrr reflectance sensors



Ok i have these on my chess robot but dont remember what i had to do to get them to work. It is the pololu digital line sensor http://www.pololu.com/catalog/product/959. Im using a arduino and 4 1.2v batteries. Here is my code. Please i forgot how to use these. 



int sensor= 4;

int x;

void setup(){ 

  pinMode (sensor, INPUT);

   digitalWrite(sensor, HIGH);





void loop(){

Start robot, hooking up sensor

The cables that came with my sensor (Sharp GP2D120 IR Sensor) are black, red, and white. But when you connect it on the start tutorial, it looks like you're connecting the cables through a black thing (sorry for my lack of electric vocab) that was used with a/the servo. My cables do not have this. They just...end. So how do I connect these to the microcontroller?

Internal Timers

Does the Internal Timers of microcontroller gets burn!

I'am using ATtiyn2313 microcontroller I blink the led by 1000ms delay but then I increased the delay by 9000000 does this burns the inetrnal timers now i'am not able to get the output and the led does not blink!