Let's Make Robots!

Wanted: Sharp GP2D12's

I am looking for someone willing to trade. I need 3 Sharp IR GP2D12 sensors with the cables and I have:

Analog input - Not getting good readings

I am using a Sharp IR Analog Sensor (2 different ones, in fact) and the readings I'm getting on both are not 'correct'.  I'm using a PICAXE 28 & a Sharp GP2D120XJ00F or GP2Y0A21YK.

Servo question

I'm attempting to put together the Start robot as my pieces come in the mail. I got my servo today, but the "you can get this here" link doesn't for me. So I got a different one from Sparkfun. In the Start robot pictures, it shows the servo with a full circle above it. The parts (3 different parts) that came with mine are not circular. There is one that looks like a cross, but the small horizontal lines are in the middle. Another that is just a 180 degree line. And another that is a line starting at the middle (like a line modelling a radius). I'm confused about how to set this up.

No response from SRF05!

Hello, I am trying to connect a SRF05 to my 28x1 PICAXE starterkit.

 Using the "start here" guide and the How to connect SRF05 to Picaxe 28 pin Project board
I am able to make the SRF05 LED flash like the guide says it should, however I am not able to receive any input in debug.

I have connected every wire like in the picture and I am only using the program provided. 

Need help with a solar-powered boat robot

Hi,

Two friends and I are starting to make a solar-powered boat for a competition (here's the link: http://techfest.org/competitions/torque/solarsplash/), and we need a little help. We're beginners with no previous experience.

Quick question

Hello, I'm a noobie at this. Is there a beginners forum? All the best

my first project

It might work, but I am not that much concerned with pressure applied to the given surface. And I can’t use motor amp changes to indicate when the “leg” is in contact with a surface because of inertia and movement speed of the “leg” that constantly changes. My pressure applied so to speak of will only be applied for rather short time periods and would almost constantly differ in pressure.

FIRST Robotics competition

I hope this is the right catergory for this post.

 

So basically our school started a new team this year and we entered into the NY FRC challange which begins january 9th. Now i personally dont know too much about the competition regarding the specs of the parts and build requirements but we can worry about that later. I was just wondering if anyone here has done this at there school or knows more about it and would be able to give a first year team some pointers.

School project tank robot

Hi

To finish my education i have decided to make a tank robot as my project. But i cant afford it to cost to much, as i am not sure how much time i will use on it when i am done. And if i decide to spend more time on my robot, i realy want it to be able to drive around outside. (more fun)

First problem i have runed into is, damm tracked based chassis cost alot. And most of them can only be used indoors. Any1 know some good cheap track based chassis that dont cost to much? And some motors/gearbox.

Noise From Motors

Hi Guys,

 Some of you may remember that I was having a difficult time getting an Arduino Motor Shield to run my 4 wheel motors on my robot Herbert.  No matter what I tried, I couldn't get it to work right so I finally decided to try a different route.  I bought two qik2s9v motor controllers from Pololu...one board for the front motors and one board for the back motors.

Qik 2s9v1 Motor Control Code

Update!  I answered my own question....I found that this motor controller has a max PWM of 127 not 255.  Once I changed that, I was okay!

 

HI Guys,

 

how to calculate motor strength?

Is there a common formula for finding required motor strength?

If I know the total bot weight and wheel diameter, could I find out what kind of motor I need. I know that gearing will come into play, but I dont know anything about these physics thingys so I choose to phrase the question as vaguely as possible.. 

Like, what kind of specs would a motor for a scooter (with me on top of it), doing 35km/Hrs require

or,  an offroader weighting 10K, doing 3km/Hrs with 10cm big wheels in rough terrain?

led stop blinking after disconnecting the programming cable

Hii!!

  I'am using Atmels ATtiny2313 microcontroller. Few days ago I was able to blink led after disconnecting the proframming cable. but now after disconnecting the programming the led stops blinking!!!!!!why???

Anyone Please help me why this happen????

Plzz help me!

Mac OS X and PICAXE USB Cable

I have tried to get the USB cable that came with the PICAXE 28X1 to work on my MBP (OS X), without any luck.  I have tried finding advice online, reviewed the manual to no avail...

I loaded the AXE027 driver (as suggested in the manual) and then I went to System Preferences > Network and attempted to connect but I get the following error:

Could not negotiate connection with PPP server.  Please verify your settings and try again.

KTY83-110 sensor maximum temperature

Hi all,

 One question for you:

 What do PTC sensors as this one KTY83-110 (datasheet here: http://www.datasheetcatalog.org/datasheet/philips/KTY83_SERIES_5.pdf) do when the measured temperature exceeds the one specified in the datasheet? 

In this case it is 175 degrees celsius, the temperature I would measure might go well over 200 degrees celsius.

Will it still return a reading? Will it smoke or will it blow?

parallel, sync, async data transfer

which one is the fastest amongst those three?

line follower

want to build my first bot and it wil be line followwer looking for the simplist and cheapest to help me start to understand electronics any suggestions

hbridge basic question

Does a hbridge requires a positive, negative, and ground?