SO.. i might have bitten off more than i can chew

[testsubject27]

let me start off by saying hi to all as this is my first post.

Im currently studying a L3 btec in engineering and after getting top grades for my first year i have selected to make a Photovore for my last year project. to make my first robot more interesting i wanted to give it a memory recall system to prioritize high light locations and go there first.
and now that the first of my basic components are arriving i have found that i have no idea what i am doing with just the photovore, let alone the memory system.

so far i have 2x 5v motors, some 555 timers, lots of photo resistors, some zener diodes, 20 x NPN transistors, 25x in4001s, and 1 ultrasonic sensor unit for arduino, i already have an arduino Ono basic kit as well. i have also ordered the AEX001u picaxe board and chip to give options when it comes to programming.

I need so much help. any advice (and criticism served with help) is very welcome.

[mstacho]

Generally speaking people come onto forums like this with very similar problems to yours and they rarely get help :-P The issue is that you aren't asking *specific* questions and haven't really shown us that you're trying to solve the problems that you have.  This is OK (it takes a while to be able to break a large project up into smaller chunks), but you won't get help until you at least try.  Here are some questions for you:

- Can you sense light?  How are you planning on doing that?
- Can you move your motors?  with what?
- What is your plan for turning/driving forward?  How many sensors will you use and how will you read them?

I strongly suggest you work on this one step at a time.  Memory is not feasible for you yet, so don't bother until you get the basic robot working.  Since you are still learning even the basics, some of the steps below might not seem to be relevant until you move on to the next step.  I suggest you do not skip any.  Also, keep in mind that this is a suggestion only - other forum members may disagree!

1) Read the intensity of light coming off of a photoresistor - there are MANY ways of doing this, but the simplest might be a "voltage divider" circuit.
2) Dim/brighten an LED - this is the fundamental skill needed for making motors move at arbitrary speeds, but it's simpler because you don't need to worry about making sure you can give your motors enough current.
3) Dim/brighten TWO LEDs with a positive and negative voltage (this means: put the LEDs in a circuit such that their biases oppose each other.  This allows you to experiment with how you would make your motors turn forwards and backwards, again without worrying about powering the motors.
4) Do the above 2 projects with a motor (take the old circuits and interface them to something that can power your motors)
5) Do the same thing for the other motor (you need at least two motors to make the robot move forward and turn)
6) Coordinate the motors using the arduino - get them to move the robot forwards, backwards, and to turn left and right.
7) Mount two light sensor circuits on opposite sides of the robot and make those sensors control how the robot turns.  Voila, a photovore!

Mike