Let's Make Robots!

How many PIC users here

I was wondering how many PIC users are on LMR and what languages are being used.  I am currently a fan of the dsPIC33's and use C and assembly for programming.

PCB Fabrication

I just discovered this site http://www.pcb-pool.com in the new Servo magazine. I went to check it out and was surprised. I can order 100 PCB boards of my shield design for $330 with 8 day turn around. SparkFuns batchPCB which is what I have been using would cost 1445.95 for 100 of the same board, and they take about a month to arrive.

picaxe or arduino automated ball pick up?

I have a picaxe and an Arduino, I'm trying to make a robot that scans for a golf ball, picks it up, then returns it to me, I found the CMUcam, but it is very expensive, is there an easy way to do this task? Am I overthinking this?



thanks :)

Beginner here. I need some direction...

I have come to a point in my life where I have some free time for a new hobby and I think robotics is something I could enjoy.

As I understand it, the following seems to be the basic skillset necessary to really get into robotics:

-  ability to understand and create mechanical features with your hands

-  have an understanding of electrical circuitry (especially in the context of commonly used robotics components)

-  have an understanding of event driven computer programming

Accurate temperature reading


Sorry if this post is in the wrong place but I don't know where it should really go?

Does anyone know if there is a piece of hardware that I can connect to an Arduino that will give me an accurate temperature reading. 

Are thermistorsaccurateenough to get a reading from?

Thanks in advance,


12vdc 5 Relay Board - WHO want IT!

Hi LMR's

I giving a way 2 of this nice 10 relay boards. Salvaged from working a control system to be discarted.

They are 12 vdc coils drived by 2 ULN2004, also have indicator power led and filter in the OUTs.

The board measures about  3.25 x 4.0 inches.

I hope that 2 of you people can use them.


Update------- They are SPST, one make by relay.


darlington drivers

Hey all.

Calculon has a question about the uln2803 darlington driver. He has a datasheet that says "the darlington pairs may be connected in paralell for more current-carrying capacity."   Calculon wonders how this is done?

Would that be pair of darlington pairs? And if he wanted more current capacity than that, what transistors would he use to make his own d-pair?

Calculon thanks you.

Soldering station...

Is there a particular rated (power) soldering station that I should look to buy?  Also - what tempreature should I usually run it at for day to day use?

Thanks in advance,


Remote control thing

I really dont know what the exact definition of a robot is...(Being autonomisnous*) but i am going to attempt to make a 4 wheeled remote control hybrid car with AA and solor panel on top...my goal is to be as fast as i can controlling it.

Items already planning on use http://letsmakerobots.com/node/5446 ... is it any good? and are there any items/stuff that can help me or intrest me on this project...thanks for your help and hope its not too stupid of a question

what will i need? i know a source/wheels... what else/what prodects?

My switch/case statement isn't working?

Ok I'm trying to to use the switch/case statement but can't seem to figure out what is wrong with it.  I thought I was doing everything right, cause I looked around.  I'm using an Arduino.


void mydirections (int myAngle, int distance)
  case 10:
  if (distance < range)

  case 20:

  if (distance < range)






My first robot help

Hello i am new here...is there a simple robot to make that is remote controlled and runs on AAA battery? or is there something to this i dont understand yet? 0_o

 Totally new ..know nothing and REALLY want to get into this if anybody is willing to teach me a step or two

trouble with Srf05/Srf005 help please.

hi everybody, ok i first got into this page a few weeks ago, and the idea of building and putting a robot together has always been there so i instantly got hooked, thing is i got everything ready but my Srf005 isnt giving any readings on the b1 section when i copied/pasted the code that makes the srf005 enter into debug mode, which fritsl gives us in ''look here on how to hook this up'' (http://letsmakerobots.com/node/66) located somewhere in the start here robot, and no response if i wave my hand in front of it either.

Half Life Full Life Consequences: Free Man

I can't handle the stupid alone, so I decided to share.

Safari problems - popups

Mintvelt posted in an obscure part of the forums about popup problems in Safari. I would like to hear from others as well. That's why I am posting in this forum. More people will notice this in the Recent posts and Unread posts.

Chassis support for big bot... help please?

I have just resumed my project and still dont have a valid chassis idea, here are some pictures, please dont hesitate with any and all suggestions.

But some might not be considered because of the fact that I dont have a welder, CNC, lots of scrap metal.
I have not drilled on the caster wheel, because I think I might upgrade after realizing all of the bot's weight will be on the caster.

Inconsistency in my L293D

Sorry, I have no schematic prepared to make this easier.

L293D by ST Electronics (datasheet) (quad half-H-bridge), only one power source: 5V from battery.
V1 = V2
Enable pins for 1+2 and for 3+4 are high.
Input pins for all half-bridges are pulled to GND via 22kOhm resistors
Motors connected to outputs: M1 to outputs 1+2, M2 to outputs 3+4.

All on the breadboard, I have an extra wire in the V+ bus. I use it to make the inputs high. Start experimenting.

LMR DAGU Contest rules anyone?

Oddbot mentioned in another post that some rules would/should be announced regarding the LMR DAGU Contest.

I thought the rules were vaguely outlined as something like:

1 Use the Mr.Basic kit.

2 make sure your robot is way cooler than the other contestants.

3 good luck.

-So, do we need any more rules? Do everybody have to use all the parts from the kit? Which partscannot me excluded? Is there an upper price limit?

Looking for foam tires that you can mount to a servo

I have been looking around the internets for foam tires that are made to mount to a servo horn. Any links?

Props to the Arduino

I found this article and thought all of you Arduino guys would appreciate it...

I have to say though I give props to both the Arduino guys and the picaxe guys as they have given us this great tech thats easy to use. I think articles like this help to inspire us when we may not be totally "feeling it"...which happens to me on occasion..

Diptrace vs Eagle

So I've been fidling around with diptrace and have really enjoyed working with it. Drawing out your schematic is simple enough, and converting it to a layout is trivial as well. The one thing I've noticed though is lack of some simple components when using the layout mode.