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If you are not familiar with electronics it will be very deficult to guide you to build your project which is very simple and nice. So I advise you to get some electronics guy to do the electronic part, and you may do the visualization part.

AHA, now I got the point, I thought it was a toy car.... - You can put a speed meter to show the car speed. - Ofcource break lights are abvious.

If you are not familiar with micro controllers, then the 555 timer will be a good solution, but your idea states that each timer will drive 2 LEDs so you need 32 timers (WAW, a very large and mesy board), so there are two solutions: 1- Use a micro controller (ATtiny2313 as I suggested before) if you know how to program one. And the board will be simple and prety. The datasheet of this uCont. is found onthe Atmel's web site "www.atmel.com" 2- Or use two 8bit counters and two 8bit buffers (or one 16bit) and a timer, but in this case YOU have to connect the LEDs to the counters in such a way that when they count (up or down) the LEDs will look like switching randomly. The timer will drive the counters and you can use a variable res. to play with the speed of switching.

you can provide your car to give signal when turning left or write if it does turn. By the way, is it a remote controlled car or what..?

Well, if you have to use the serial port for data transmit, then you can use the USB port to power supply your circuit, and 100mA is enough since a wireless receiver does not consume much power as a transmitter. If you run your Atmel with low frequency (1~4 MHz) and low voltage (2.7~3.3v) it will consume current in nAmps. More over new USB ports are high power load this means they can supply 500mA. But trying the circuit given by "MP" won't be useless, try to get rid of any un-necessary elements. Then, maybe 5~7 mA is enough. Good luck

I found the UV sensor 6490, I hope it does fit your need.

If you google for "UV sensor" you will find many many choices amongst you can choose the appropriate one that is available in your area. Then use a uController to set the desired UV level.

Why don't you use the USB port for trasmiting the data instead of the RS232 port, here is a PDF doc. that describes how to do that: URL http://www.atmel.com/dyn/resources/prod_documents/doc2556.pdf The source code is even there: http://www.atmel.com/dyn/resources/prod_documents/AVR309.zip I hope it works.

You can use a microcontroller and program it to generate a random number. If you are saying that you have an 8x8 square of LEDs an ATtiny2313 would be fine or ATmega8 if you want to have more free pins to do fancy thing with them. I hope this gives you a clue, if more help is needed just tell me.

Hi everyone, I need a single chip that contains an ADC and a DAC at the same time. I found the AD7569 chip from "Analog" which is fine: (8 bit, parallel, AD/DA) But is ther any other options!!?? - The interface does not matter (serial or parallel) - 8 bit res. is enough.

This is a very simplified design just to give you an idea. You may use any cheap micro. If the 7seg is CC then you should use BC337 instead of BC327. If you need more help tell me.

I think thermo-switch could be a good name