Problems with Motor Controls w/ Keypad Input

Using Arduino Project Guidance
1

So I'm trying to control a stepper motor (or maybe more) using input from a keypad shield w/ LCD screens.

Stepper motor (3v,6A) http://flashcutcnc.com/pdf/MP-2303%20Land.pdf
Arduino UNO R3
Keypad 4x4 input : http://iteadstudio.com/store/index.php?main_page=product_info&products_id=308

The problem I'm running into is the stepper motor only uses 3V and requires about 6A and I could not find a motor shield that can output 4-6A and 3V.

I'm thinking of buying this shield
Megamoto Shield: Robot Power Products - MegaMoto Plus Motor Control Shield for Arduino
and use PWM to control the voltage. I've never done this before so I'm not sure how this will work out. Any thoughts?

Another problem is that I cannot use these shields together since there are pins conflicts. I'm planning to connect two arduinos using i2c but it interferes with the keypad pin A4-5. How do I make this work?

Any help will be much appreciated! XD

2

Your keypad/lcd shield is using 13 pins out of 18 available arduino pins. There is no way you can use it for any realistic project involving more hardware. Use a serial LCD and keypad to possibly reduce pin count and you may get to pick the keypad connections (8 pins if you connect directly to arduino).

FYI, I am selling this LCD keypad combo:

http://www.inmojo.com/store/liudr-arduino-and-physics-gadgets/item/serial-lcd-back-pack---phi-panel/

For 2 Arduino pins, you get 4x4 keypad and LCD.

3

Thanks for the input. I think I might get your keypad instead. But theoretically, it is kind of like having another microcontroller with a keypad with it :). Now I just have to solve some problem with the motor controller.

4

eigenz:
Thanks for the input. I think I might get your keypad instead. But theoretically, it is kind of like having another microcontroller with a keypad with it :).

Yes, my panel is using ATMEGA328.

5

Do you by any chance which arduino pins are used for the kit?

6

eigenz:
Do you by any chance which arduino pins are used for the kit?

The backpack uses all ATMEGA328 pins except for analog 4,5. That is not your concern since these pins are the pins on the on board ATMEGA328, not your Arduino pins. Your Arduino only needs 2 pins to connect to the panel.