controlling a dc motor with a 18200 H-bridge

I need help in determining which pins should be connected to the arduino for direction and braking controls. I have tried to use the l293 H-bridge but its current output is too low. therefore, the motor that i need to use will not turn, but smaller motors do turn. please help!!

which pins should be connected to the arduino for direction and braking controls.

??? Any pins you like, the motor controller has logic level inputs and the arduino provides the logic level output. A big motor is no different than a small motor in this respect.
Is there something missing in your phrasing of this question?

Given the block diagram on page 2 of the datasheet (you didn’t specify the manufacturer, but they all should be pin-compatible):

http://www.national.com/an/AN/AN-694.pdf

Pins 3, 4, and 5 of the 18200 control direction, brake, and PWM respectively. Your motor outputs are on pins 2 and 10 of the 18200. Pin 9 is the “thermal flag” output; hook this up to another pin on the Arduino, and you can tell if the chip is “overloaded” and shutdown the system or whatever.

If you look on page 9, you will see another diagram - note the two 10nF caps - they are (should be?) each connected from pins 2 and 10 to pins 1 and 11 (respectively) as “bootstrap” caps to provide a charge-pump to the internal FETs (I think that is right). They are probably important to this thing actually working, based on what I little remember about FET h-bridges.

Also, if you connect a resistor (not sure of value, but the spec sheet should give hints) between pin 8 and ground, then run a line from pin 8 to the Arduino (to one of its analog inputs), you will be able to sense a voltage proportional to the amount of current being drawn by the motor controlled by the h-bridge. High current = stall condition; extremely-low current = slip condition: Monitoring this line would allow you to easily implement a traction control system.

Tons of info on how to use these h-bridges in that spec-sheet, so read it very carefully. Also, remember to mount those h-bridges to a suitable heatsink; you won’t get anywhere near the current capability from them without it (fortunately, the thermal-flag circuitry will probably kick in and shut things down, at least from the h-bridge’s view).

Hope this helps - good luck!

YES this is helpful, thank you!!