Let's Make Robots!

Arduino Motor Control Code Help

I am currently using a arduino duemilanove, and it is awesome. I have been playing around with it for a couple of days now, and I really like it. Anyways I figured it was time to start to building a robot. I decided to start with the motors. For the motor control I decided to use guibot's tutorial. It worked fine, but the motors only traveled in one direction. Because I wanted the motors to also travel in reverse too I decided to experiment with my own code (on only one motor) that looks something like this:

High Byte, Low Byte, which is which in Arduino

Okay, so I've got a question about how Arduino considers High and Low bytes. By way of example, here's how I thought it worked;

0x00FF == 255, High Byte is 0x00, Low byte is 0xFF
0x0100 == 256, High Byte is 0x01, Low byte is 0x00

Voltage regulator problem

Hi, i recently added a sharp ir sensor, a servo, and a picaxe 8m to my robot, trix. The power supply i made for the picaxe board and sharp ir sensor assembly was simple and should have worked i thought, it was a five volt regulator from parallax, a 9volt bettery clip, and a 3 pin header for the power out (5volt reg, un regulated 9v, ground), However when i plugged the power supply into the picaxe board, my multimeter read only like 2.5 volts across the picaxe and the voltage regulator heat sink got so hot i burt my finger quite a bit.

A Video Game Quintet

Ok ok ok it's not a video about robot. But it says "Videos from around the web you have found and want to share" and well, i just really wanted to share this one with you... i'm sure most of you will like it :D

Radio emitter and receiver query

Hi all..

I'm new here so hello and be gentle!

LMR "mark all as read"?

Is there a way to mark all items as read so that the "Unread posts" page can start fresh?  (Other than actually reading all posts?)

 ~michael

Embedded: "Real men(and women) program in C"

A great link on the use of c in the embedded technology world.

how does XORF work?

howd yu do?

I finaly caught on to the PIC assebly language!

I am using a pic on a simple little robot with the usual bump, revese, turn, obsticle avoidance. it will do more than that later but I havent even writen a PIC program yet so I am starting small. anyway there is on thing I don't understand in the tutorial i read. it is the XORFcommand. I understand xor gates but how does it work here; http://www.pictutorial.net/?page_id=152

it says 

Question about this Transistor!

Well, I was surfing eBay a few days ago.. and came across an exciting deal..100 S9013 NPN transistors for $4 with free shipping..

Of course, before looking into the specifications too much, just scammed over and seen that it can handle up to 30v at 500ma..

But I seen that the "Absolute Maximum Emitter Current"  is -500 ma.

 http://www.datasheetcatalog.org/datasheet/auk/S9013.pdf

Parallax Board of Education board + extras

This is a collection of items to make up a complete Parallax Board of Education training kit. The Basic stamp is a new BS2P processor which is faster, more memory and comands then the original Basic Stamp2. It retails for $79.99. The board is in mint condition (only used a few times) and tested before listing. Everything else is new except the USB cable I used with my camera a few times. Parallax retail value of over $190, not counting the cable and un-opened bag of electronic parts that go with the book.

problem with IR remote upgrade

i was trying to see if i could make sounds, LDR-test and ir remote test.

upgrade stuff here: http://www.rev-ed.co.uk/docs/axe040.pdf

but there is a syntax error :(

3803545020_97a5fdd508_o.jpg

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please help!

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real time servo & motor control

Hi there

Sorry for this post as I`m sure there are many like this....

I need to be able to control upto around 70 servos and motors from a pc or networked pc`s 

I want to start with one servo and one motor for now.

the thing is tho, I know there is MANY products to set up a sequence of movements on software -> download to controller then run the sequence. or something like that

NiCd discharge question

i have any questions about the topic

 

when a nicd cell have to be recharged? i am taking about voltage... 1,15v? 1,10v? 1,05v? 1,00v?  per cell

i have a 3xcell batt pack in a bot , the system self recharge when the voltage reach 3,4v, so 1,13v  per cell

is it an insufficient discharge? which can bring to lazy effect?

 

assuming that X is the ideal voltage per cell  to decide to recharge..... have i to read X  when the battery is under load or when it isunder no load.

Motor Driver question

hallo

i'm trying to build 'start here' robot using  arduino as the brain 2 gear motor as the driving force.one of the forumer has point out to me that i need a motor driver to control the motor for forward and reverse movement,

my question is(sorry if sound stupid) do i need 2 motor driver for the 2 gear motor or 1 motor driver is enough.and how to use this motor driver.

thanks for the help.truly preciated

 

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How to use two analogue devices with only one analoque input?

For now it's theory, it's for a future evolution of a future project (yeah i know that's two "future")
Ok actually i'll need 3 analogue inputs (one SRF05 ultrasonic rangefinder and one 2-axis accelerometer), but the 18x picaxe chip has only two. So basically, i need to find a way to share one of the inputs. As i won't need to read the all inputs at the same time, maybe it's doable.

So two ideas came to my mind, each one with its pros and cons.


First idea : a SPDT relay.

With that, two solutions :

Where to find Timing belts and pullies?

    Well for the next iteration of my sumo- "bot" I will need some timing belts and pulleys. The pulleys need a 6mm bore though, I've been searching Google with minimal success, anything I find is either really expensive or needs to be ordered in bulk, can anyone help out?

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