Let's Make Robots!

PIC18F452 and DC motor controller.

Hey folks.

 Becausse the PICAXE kit already ships with all the components (er, most of it) glued, I wanted something more challenging. So, I am trying to build my robotic brains from scratch. 

Whilst I have come across quite a few (video) tutorials with circuit diagrams using PIC microcontrollers, I am not able to use a motor controller. One such is here: http://www.seattlerobotics.org/encoder/200001/simplemotor.htm. 

Picaxe and iPods... OH YEAH!!

Just found this baby... I am now looking for hackable iPod connectors buyable from the US...



**Update** (5 minutes later --I love the Google!!)

Sparkfun has got them!!


sfr04 programming in C

Hi all,
I am programming an SFR04 sonar device using C. I have got a PICDEM2 plus starter kit from Microchip. com.
I am using an PIC18F chip that came with the board/kit. What I would like to do is use the L.E.D's on the kit to flash when an object is detected. I have a progamme but am having trouble incorperating the L.E.D's with it. I have put the programme on an attached file. Any pointers or help would be great.



where to find connectors

I was following the "first robot" tutorial to get ideas on where to start and it said to buy some pins. they are great because the servo connectors just plug right onto them, but i cant find any similar connectors to put on the ends of my motor wires etc. its really hard to solder to the output pins so i would really appreciate it if anyone knows where they are available.

Basic Atom Programming Help Needed

Ok Basically this is my pseudocode. It's very rough though I did it in around a minute.


start both wheel servos full speed

if object too close in sight move back and move ir sensors left and right to choose direction

if object is blocking left side and not right.. right servo spins backwards and then both servos at full speed

if object is blocking right side and not left... left servo spins backwards then both servos at full speed

if object is blocking both sides... move back and make right servo moves backwards and goto main


DC motors: "altered brush timings"

In this thread, under Chris' noise question, Cliff suggested that motors sometimes are optimized to run in one direction. To the detriment of the motor's performance when running in the opposite direction. Ken observed the same thing in car-window-wiper-motors. Now I want to know more about this.

Have a look at the motor I use for my Theo Jansen Leg experiments.


Needing servo help!

I'm really hoping someone can help us.  I am trying to help my 10 year old build a robot.  He is using a basic stamp kit and three servos.  He rigged the servos to turn 360 degrees. 

Track design for tracked robots

I am brand new to the robot hobby with questions about track profiles.

The high sided triangular track profile of Wall-E or Johnny 5 looks really good, but seems to make inefficient use of track links.  Other than good looks, is there a good design reason for this profile?

Of the other general profiles available (parallelogram - WWI tanks), (rounded rectangle - Christie type WWII tanks), (inverted trapazoid - short base down), what are the relative merits in terms of efficient use of links vs. object climbing ability?

Analog Logic Circuit with Timer/Delay, need some help


I have a processor which needs to be powered on by pulling a pin LOW for 1 second.  I would like to set the system up so that whenever a battery is present, the processor turns on.  I have a programming background so I am having a little trouble turning ths into an analog design.


Here is what I have:

3.7V battery input (Li-ion), 900 - 1100mA, call it BAT

ON# pin, which needs to be pulled LOW for 1 second.

POWRMON pin, which is HIGH when the unit has been turned on OR ON# pin is pulled LOW.