Hey guys, I really appreciate if you could help me .
We will be making an Obstacle Avoidance Vehicle for our Final Year Project, so far we have bought the Materials needed listed as follows :
- Arduino Diecimilia Board
- Infrared Proximity/Collision Sensor http://www.e-gizmo.com/images/ikit/collision.gif
- 7v Bipolar Stepper Motors(2x)
- Universal PWM Stepping Motor Driver http://www.e-gizmo.com/images/ikit/PWM.gif
So here's the thing guys, apparently the Universal PWM Stepper Motor Controller as shown on the image is capable only on controlling 1 motor . Now I'm kinda confused on my decision if buying 2 PWM Stepper Controllers would still be okay. :-/ Any suggestion would be highly appreciated. Thanks in advance.
You might have better luck if you return the servo controller and servos, and then try to find an old toy r/c car for your platform.
Reverse engineer the motor (and steering) control circuit on the controller board in that (bypassing the radio-control RF portion), in order to connect it to the Arduino. If you are lucky, you might get such a car with its radio-control transmitter; on a bench, you could then back-trace the motor leads on the controller board through whatever is being used as an h-bridge, and probe inputs on that circuit from the RF section to determine what lines are being held HIGH and LOW to interface the Arduino to (via digital outputs - depending on the car and the controller, you might have to do some minor level shifting of voltages, too).
If you can't find an R/C vehicle, try to find a wired-control "tank" toy that has full function controls (left, right, forward, reverse); tear it down to just the base and motors/treads, then get a dual-DC motor controller of some sort (you can either buy a shield, or pick up something like an L293 or L298 h-bridge IC and interface to that).
Using such a pre-built vehicle saves you the trouble of having to deal with the mechanical construction, and possibly even the motor interface details; if you can find it used at a thrift or junk store, it shouldn't cost much, either (just make sure that it seems like it is a working device; turn the wheels and such, listen and feel for good mechanical workings).
I'd agree with cr0sh. I recently modified a RC car myself to interface with Arduino. Most RC cars nowadays use a separate board for receiver and the output lines are clearly marked.
All I did was to cut the output line traces and insert my control signal from there (need to pay attention to the voltage though, if it is not within the TTL specification, you may need to add some kind of clamping circuit)
In terms of obstacle detection, you can either use IR sensors or ultrasonic sensors. Ultrasonic sensors typically have a longer range and wider sensing angle.