Let's Make Robots!

Window wiper motor for a steering mechanism (centers when you release the stick on the controller)

Hi all

I am building myself a remote controlled car with a lawnmower engine, and am currently having some difficulty in designing a steering mechanism, hoping all you guys could help.

What I have is a window wiper motor to operate the steering system and a servo, now I just need to design a system as basic as possible (hopefully just using switches, levers and wire).

micro controller

Is it possible to have one central micro controller connected to 3 other micro controllers? And let the impulse of that micro controller control the other micro controllers. My system works on a censor bases that skips the secondary control servos and feeds its impulses directly to the main servo. From there to the secondary servos and to the mechanical response. So the censors are connected to the main servo.

Has anyone heard of this Ultrasonic Sensor?

The model is SP-40-38F. You can find it here: http://www.cutedigi.com/product_info.php?cPath=278_295&products_id=4282&osCsid=d133de8082a4556d02f27cdf248ae912

I would like to buy a few but after looking at the site, I am a little hesitant to send them any money.


Arduino EMF detector

Arduino EMF detector !!!

Interesting Sensor project from makezine

Does UART require a pullup resistor?

I am trying to understand how UART communication works.

I have not read anything stating that pullup resistors are required for UART, but conceptually some type of pullup is in fact required because otherwise there would be an unknown state.

Is it part of the UART standard that each device on the bus must have it's own pull-up resistor?  If so how can this be because if the pull-ups are of different voltage then the state is again unknown.


UART level translation, what type of translation IC is required?

I have two devices, and need to figure out how to translate between them for 2 wire UART.

U-Blox NEO-5G, 1.8V
Input low:  0.22V (MAX)
Input high: 0.91V (MIN)
Output low:  0.4V (MAX)
Output high: 1.4V (MIN)

Telit GC864
Input low:  0 - 0.5V
Input high: 2.1 - 3.3V
Output low:   0 - 0.35V
Output high: 2.2 - 3.0V

UBlox -> Telit
LOW: .4V (MAX) -> 0-0.5V   (WORKS)
HIGH: 1.4V (MIN) -> 2.1-3.3V (DOES NOT WORK)

Picaxe28x1 kit and those ribbons..

*warning* Extreme newbie questions below..

I have the 28x1 starter pack and it includes 3 ribbons but I'm not sure of the correct/best way to use them..

Is the red stripe at the top of the ribbon supposed to indicate something? 

My First Robot - Motor control for tracks

Hello all

So, I've been lurking this forum for a while now and finally decided to make my first robot.

I started out reading the "Start here" guide - and it's a really cool guide by the way :)

Motors and Arduino

   Hello, is it possible to control regular small DC motors with an arduino board? If yes what limitations do I have?  can I use the PWM feature to increase decrease their speed?+

what about servos, do I need a motor driver or can I control them with just an arduino?