Let's Make Robots!

Using PiFace but still using I2C

I got a PiFace Display in the mail not too long ago, and just cracked it open.
I got it as a tester to write a review, because I wanted the LED display and the infrared on it.

Making a PING sensor control a DC motor

Hi, guys. I'm kinda new to this robot-scene. I've been doing it for about 3 days i bought a arduino uno r3 and a few other odds and ends to make a simple robot. ive got 2 DC motors(3v), A PING sensor, and everything else to make a robot(don't feel like going into detail lol). I know how to run the motor and the sensor by themselves but i need some help making the sensor and the motor cooperate. Any ideas

 

P.S. i have programming knowledge so i dont need it (dumbed) down lol

Motor Arm Length Calculator

Below is a picture of what I'm trying to build. This is the motor that I'm using, which has plenty of torque.


Servo problems!

I'm having a lot of problems with the servos I'm using to build a quadruped robot. I should start by mentioning that I bought the servos from Dagu like 4 years ago, BUT most of them had never even been unpacked until recently.

The problems are the following:

Printing with trimmer line

As many of the shout box regulars have found out i have my printer up and running. when i finished it i had no material to print with and a massive desire to see my monstrosity work amd remembered something i had read online.People were experimenting with trimmer line (the stuff thats used in weed wackers/weed eaters etc...) but last i had looked into it deltas and bowdens were the new and most people were running 3mm filament. well after looking around i found .065 inch line which measures out to ~1.68mm.

Parts Prices (In US Dollars)

Here is the analysis I have done so far. I didn't look everywhere, but I did learn 2 things.

  1. You can't buy everything from 1 place
  2. It is cheaper if you buy from outside of the US on some parts

Here goes my summary: (For all intents and purposes, when priced in £ double it for US dollars. It is a bit less than double, but after your credit card company charges a fee to convert the purchase it will be close to double given the current rate of exchange on 5/7/2008)

Starter Pack (Picaxe 28 with USB cable)

Servo problems

My Picaxe 228x1 arrived today with the servo upgrade pack. I have followed all instructions but can't get the servo command to work. It appears to be trying to turn clockwise past the stop - i.e. it turns all the way and then buzzes. I can get it to move ok with pulsout commands so I don't think that the servo or any connection is fundamentally broken. The following is my program - the servo 0,150 is the command that isn't working as expected (any position I give seems to give the same result)

Anybody got any ideas what I've missed?

 

Advice - PICAXE to PICAXE IR

Guys-

The goal is to allow 2 PICAXE chips to speak with each other via IR.

What receiver and transmitter have you all had success with. Where can I purchase? (links?)

Thanks all.

Software PWM

I was hoping to avoid wrighting my own software pwm for the pic but it looks like i've arrived there.  the motors and tracks I hot glued toghther don't drive straigh so the only way I can think of fixing it is to use PWM to slow down one motor.  I know I could use the one hardware pwm to slow down just one motor but thats going to be used in the future for somthing else so I have to create the pwm myself in software.

Help with 555 circuit.

Well, I have got the 38khz distance sensor working in picaxe form.

Here

Here

Now I am trying to wire-up a stand-alone unit with a 556. Now I know this is a RTF(data sheet) moment and I know the resistor/resistor*cap/2 (or whatever) equation, but the final circuit is still above my head. Are there any of you circuit guys out there that can do a little drawing for me? Maybe with a couple pots for fine adjustment? I plan on the final output going into a picaxe using the pulse-in command.

Thanks in advance.

n/a

TENET TECHNETRONICS is now an official Distributor in INDIA for Arduino Boards

TENET TECHNETRONICS is now an official Distributor in INDIA for Arduino Boards an open source Electronic Prototyping/Development Board, an easy way to procure boards in INDIA. These boards will help your  electronic ideas to become a reality. We also host a range of electronic boards - Micro Controller, VLSI and Embedded boards. We host a wide range of electronic components to cater your needs.

Boards we currently distribute
    Arduino Mega
    Arduino USB/Arduino Duemilanove
Arduino Pro
Ethernet Shield for Ardunio

Picaxe PWM and servos

I have tried using picaxes PWM outputs on 2 robots now with limitted success. The biggest problem I have is that the PWM frequency although adjustable is very high (typically 16KHz with a 16MHz resonator). This causes the windings of the motor to have a much higher impedance resulting in poor torque. When I use the setfreq command to drop the clock speed very low (500KHz) then I get good torque even with a low dutycyle but the processor is so slow it is almost asleep.

Big choice of servos in Europe

Hi,

I'm making a robot arm, and I need 1 shop to buy all my servos from (legal reasons).

Problem is, the shop has to have all the range from powerful and durable high-torque servos with full ball bearings (about 25 - 30 kg/cm), to lighter standard, to even some very lightweight mini servos.

So far the shop with the best choice is http://www.active-robots.com/products/motorsandwheels/servo-index.shtml, but I would be very happy if someone coined me some more or better options :)

Hello! I'm new here

 

Hi there. I have seen a few videos from this website. I've even been told a few time to sign up, so here I am! :) Glad to meet you all! Lots of fun projects on here. I've been looking through the Robots and Blog area, some real neat stuff.

I'm a robot builder also, sorta, kinda. I spit out new ones often, so I may not have time to post them in the Robots section. But I really like the active forum here! I'll probably be around often. 

Here's a few links to some of my robots if you're interested: