help me to build a line follower robot ...plz

nayan

I m building a line follower autonomus robot....but facing some

problems........plz help

i) i want to take the input from sensors , where(which port) should i take

the input. How to convert the analog signal from sensor to digital signal for

microcontroller (ATMEGA32)
iii) which sensor to use ....it should be able to work when other flash lights

and lasers are allowed inside the arena

iii) Out put from the microcontroller will be 5v ....this is not sufficient for

motor .....how can i increase the volt ??

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i shall be very glad to get the answers ...plz give the answer

elaborately......and mention some factor that i may be missing....thanks

Mike Green

This is a support forum for Parallax robotics products. We cannot help you with other microcontrollers like the ATMega32. In terms of sensors, have you looked at Parallax's QTI IR Sensors? Browse through the sensors portion of the Parallax webstore. The various webstore pages all have links to documentation and sample programs for Parallax's microcontrollers like the Basic Stamps and the Propeller.

If you go to the main Parallax webpage and click on the Resources tab, you'll see a link to Nuts and Volts Columns. Column #6 shows how to control small motors, relays, and high power LEDs from a microcontroller I/O pin. The suggestions are applicable to a variety of microcontrollers.

Martin_H

To keep this within the scope of Parallax products I will discuss building a line follower using the QTI sensor and converting output to a digital value using the BS2.· This is a good sensor as it has many use options, but any sensor with a similar schematic would be used the same way.· This might help you with your question indirectly.

What you do is connect one I/O pin to supply power and another to read the output.· You bring the power pin high and pause to charge the QTI sensor's capacitor.· You then set the power pin low and use the BS2's RCTIME command to see how long it takes the output pin to transition to zero.

One sensor likely won't be enough to build a line follower, but two sensors can be delt with in·similar manner.· However, unless you know what you're doing use four pins,·supplying both sensors power from a single I/O pin might consume too much current and damage a micro controller.

But why stop with two sensors when you can build a sensor array and do something much cooler?

A few years back I bought Scribbler robot to use with my kids and it charges two sensors off a single I/O pin.· The schematic has a black box between the output LED's and the I/O pin, so I'm guessing the pin isn't supplying the current directly for reasons I mention above.· But I am in the process of adding two more line sensors under Scribbler so I will have a total of four!· Then I will have a line sensor array and can solve line mazes with Scribbler.

I wish I knew how much currrent the black box on the schematic could supply.· If I could drive two additional sensors from it I could save myself some work.