I had a vexplorer from a little bit ago and I busted the controller so it was useless but I thought "I'm gonna hack this" and that's what I'm gonna do. thing is i am a arduino noob and im 9 
so any code help will be greatly, greatly appreciated. (btw i am using a pin for pin replacement h-bridge for the L293) and soon when i get the cash it will be xbee controlled!
Wow, you have now mentioned your age something like 4 times in 6 posts. That's got to be a record. For the record, I have some 20 years on you.
I don't have any experience with this "vexplorer" but a quick google search reveals it to be some sort of robotics kit. Are you sure that an arduino with 16k of flash and 2k of memory is up to the task of replacing whatever micro controller the device originally had? I suppose that this would somewhat depend on what exactly would you like the new controller to do. So, what's the goal? I doubt that you can perfectly emulate everything the original did but being able to control the robot in some fashion should be possible.
it actually is a rc robot that uses two drive servos and a servo each for the claw and arm but that will be a pain to make work.(i was thinking of using the ping(( sensors with the bot.)
The vexplorer robot is radio controlled, it has a radio receiver which can control several bi-directional DC motors
Usually, there are 2 drive motors, 1 arm motor and 1 gripper motor, although the receiver can control 6 motors
The ladyada motor shield can control "Up to 4 bi-directional DC motors with individual 8-bit speed selection", so that should work if you only have 4 motors
it should but i already got 2 h-bridges for this and thats what im gonna use.(its a pin for pin for pin replacement for the L293)
p.s. i use linux too
You beat me to it while I was looking up the ladyada motor shield, which can be found here Motor Shield - Arduino motor/stepper/servo control
An arduino with the motor shield should be able to control the 4 motors, I think they are actually bi-directional DC motors and not servos
You may need an ATmega328 to run the motor shield
Have you looked at http://sanguino.cc/ or http://www.liquidware.com/shop/show/ILL/Illuminato ?
Both have more pins and better specs ( 4 times the SRAM and flash compared to the ATmega168 ), some modifications are required to use with arduino
The sanguino can plug directly into a breadboard and then you can breadboard your H-bridges
If you get a sanguino, make sure your breadboard is wide enough for it
Hope this helps
i need only 6 pins for both motors i am using only two motors and one more for the ping sensor and i already have a protoshield so im set! I just need code [smiley=angry.gif] (you can set the pins)
Ladyada has some source code examples Arduino motor/stepper/servo control - How to use which might help, some code may not apply
http://www.arduino.cc/playground/Main/DirectionalMotorControlWithAL293D
Arduino Playground - InterfacingWithHardware look under Physical/Mechanical
and anyways the wires coming from the servos are 1. only two wire and 2. have a male end on them so from what i figured they are just dc motors so in the end i am just gonna breadboard it up and figure it out and then hack the ladyada motor shield library
Make sure you power your H-bridges with a suitable external power source, the arduino voltage regulator and the arduino pins cannot provide enough power
I think you need a common ground between the external power source and the arduino
i tried connecting the motors to plain 5v from the arduino and that worked fine
(will a hicap lithium backpack do for my source?)
The arduino voltage reg can output 1-1.5A but only with a heatsink attached. However, it would be better to get a DC-DC switch mode converter if you plan to pull that sort of load. This is especially true if you are running off of a battery. DC-DC converters are a lot more efficient than the resistive voltage reg on the arduino.
The arduino itself should not be used to source more than 200ma total across all pins. This isn't much of a problem if all you are doing is driving transistors.
A high capacity lithium pack should power things well.
it will all work with what i have?
it will all work with what i have?
I don't know... Do you plan to power the H bridges off of the arduino's power? If so you at least need a heatsink attached to the LM7805 voltage reg. How much power do the motors on the robot need? You should have some decent sized caps for decoupling the power supply to those h bridges. Motors are inductive loads so hopefully your h bridge setup has backfeed protection diodes. Be sure to use fast acting diodes such as schottky diodes.
I agree with AdderD and would recommend a DC-DC step down regulator with enough amps to feed the robot
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Be careful Lithium batteries can catch fire if mishandled
NiMH batteries would work too, they are not as good as Lithium batteries but they are cheaper and a little safer
actually the battery outputs 5 volts and you connect it as so to the gnd and 5v female headers and my battery has powered a similar robot for 2-3 hours.
5v does fine for the motors though so i think I'm in good shape.(i have a heatsink if needed)
You should use a DC to DC regulator otherwise your voltage will fluctuate as the batteries discharge, this will cause issues
The arduino requires regulated power at +5VDC
You can plug the battery back, Lithium, NiMH, etc into the power jack and run it through the onboard regulator on the arduino however you should use another power source ( DC-DC regulator ) for the H-bridges and motors
Make sure it can handle enough amps, otherwise you may get fireworks, the bad kind
Heres a link to a grumpy mike tutorial on driving DC motors from an embedded system:
http://www.thebox.myzen.co.uk/Workshop/Motors_1.html
It pretty well covers everything.
i just want to run the motors off the regular power source of the arduino i just need to know if i can do that or not. (yes or no)