Let's Make Robots!

Need to hold balloons in place

Hi everyone,

so I'm a bit stumped with this project I was working on. The idea is to have 40 balloons held in place that can be individually and specifically released. Originally I was going to use hobby motors but I need something that has a little more force (to prevent people from just taking the balloons) and was thinking of using servos.

For Loop trouble

Hey everyone,

I have a small programming dilemma. I'm working on a school project where I have to build a solar tracking platform on which solar cells can be mounted. The setup I have is a solitary panel, with phototransistors on top and botton. All of this is mounted pan/tilt style using servos. I tried to set up a for loop that would iterate through each servo position and take a reading from the phototransistor, and at the end the servo would jump back to the position where the transistor had the lowest analog reading (the most light).

This is the code I had:

Common Ground?

Noobie electronics question:

I built the tristate circuit nuumio posted a while back and managed to get it working with my picaxe 28x project board. I then tried to use it with an 08pic and a little breakout board I had created for it however, I can't seem to get it working. The 08 pic has two 100k pulldown resistors connected after the outputs pins on output 1 and 2 which are then connected to 4.5v ground powering the pic. My tristate circuit uses 4AA batteries to power the motors, with the only input being the two pins from the pic.


serLCD and arduino

alright so i cannot seem to get this to work...


i bought a 2x16 serLCD from sparkfun (this one to be exact: http://www.sparkfun.com/commerce/product_info.php?products_id=9067)

Concept Question

Now that i have several small robots under my belt, along with a somewhat firm grasp of programming basics i would really like to scale up. I worked on a robot for the FIRST robotics competition which was really my first time handling a somewhat larger project. The materials required for that robot were quite expensive and the robot itself is too big for one person alone.


I'm just going to throw some ideas out there 1. to force myself to actually get started on this and 2. to hear some constructive feedback and to make sure i'm being reasonable.


robo sumo

Hey everyone,

i'm looking to get involved in some local robo sumo matches, if not start a competition at my school. We're going by the rules found here: http://www.robotroom.com/SumoRules.html

We would be sticking with the 10cmx10cm robot dimensions and following pretty much all of the rules.

Hmm before i go on i should probably ask if there are newer/ more official rules that can be found. I'm assuming most places have slightly different rules, but are there some basic guidelines? If anyone has sites with more information those would be great.


Down amping circuits

Alright so i have an electronics question and i'm not really sure what to do as i've never worked with this much power before. We have a 17 amp 12VDC battery connected to a power distrubution board, the board has 40 and 20 amp 12v outputs.  We purchased some of the cold cathodes from parallax to put some lights on our robot however i have no clue how to down amp the power from the board.


the DC to AC converters

Damn those LCDs

Rightyo, sparkfun 16x2 serial lcd hooked up to 3.3v, gnd, and the tx pin on my arduino. I just want an example of really basic code that will print something on the lcd, i've searched the arduino site and google but none of the tutorials seem to make sense. is the move to x character command necessary? I just want print like the values from a sensor or what not which seems easy if i could just have it print something simple.


 this is my code:

Looking for serial servo controller

I hope this is the right forum category.

I am looking to operate 12~ servos with a serial connection and i'm looking for a serial board that will either be compatable with the picaxe X1's or the arduino 2009. Sparkfun only seems to have an 8 servo controller and i've been out of the robotics area for a while and don't know where to look. 

Servo Strength

Alright, so i've been out of the game for a while and most of my parts are being used. I now need to order several servos (12 in total) for a hexapod build I am planning. Each leg will have 2 DOF, with one standard servo (i'll come back to this) connected to turn the leg right and left, and a more powerful servo (coming back to this again) to move the leg up and down. I'm not exactly short on cash right now, but I really want this to be a relatively cheap build.