Let's Make Robots!

Problem with robot program select menu

I have a problem with programming a menu for selecting my programs for my robot.

The program has to show 9 numbers from 1 to 9 on a 7-segment display, representing a program(avoidance, linefollowing,....)

With 2 switches you go up or down a number and you comfirm with the 3the button(selecting the program you want). The 3 buttons are 1 input that gives a different value depending which button is pressed.


Line following sensors questions

I am planning to place 2 line sensors on my robot project(ATmega8). I want to place LDR line sensors. Now i have a few questions.

What is the best distance to placethe sensors from each other? So that I have no bad readings and I still can follow the line 'smooth'.

What is the average breadth of a white line?

What is a good design of this type of sensor(LDR)? I would just place the LDR next to the led, is this okay?

And what is a good algorithme to use with a L293D with no pulse control(each motor is always on 100%)?




Amplifying ATmega8 signals

I am doing my final project for school at the moment.

I have a bit of a problem.

I use my ATmega8 with a BD243C transistor to switch a relay.

Now is the problem that the signal that goes to the transistor is to small to fully switch the relay. I was wondering if I could use this(http://www.datasheetcatalog.com/datasheets_pdf/T/L/0/7/TL074CN.shtml) TL074CN IC for amplifying the ATmega8 signal and so fully switch the relay. Can this be done?


I have not much time left to finish this project, so I would appreciat all help.


Question: Turn on a pin on a parallel port

I need a program to control a pin on the parallel port.

It need to work on windows xp and it needs to turn only one pin on.

The idea is to turn port D1 on with program: Pport1 for example

and D8 with an other program

so that with my project with voice control I just need to start the program with the voice control softwareto turn the port on.







Danny Temmerman

interface with atmega8 with parallel port

Does anybody of LMR knows how to for example turn port D0 on the atmega8 with the pc linked to the atmega8?

For example when I start this program the atmega8 turns on port D0 and when I turn an other program on port D1 turns on.

Which program do I need and what circuit do I need?

Can somebody give me an example program?







Danny Temmerman

Voice controlled room

I have an idea about a voice controlled room.

I would use an atmega8-16PU to switch lamp and other items on

I have an old pc laying in my room with windows 2000.

It has a serial port, a parallel port and 2 usb ports.

I want it to interface with my atmega8, but I am wondering how you use voice control with it.

I could also use an arduino, but for now I am thinking it al out.

This is an idea for home automation.


So does anybody now how I would program my pc for voice control.