Using MicroCore-11 and a Quad Motor Driver Board to Implement a MicroMouse

Recommended Hardware Configuration:

We recommend you arrange a MicroCore-11 MCU module, a Quad Motor Driver Module, and a Prototyping card in a stack configuration, similar to the photo above.  Add some IR distance-measuring modules and you're ready to roll. A a solenoid driver circuit is included on the motor driver board for such purposes as grabbing the "cheese" at the end of the maze (you provide the motors and mechanical design, of course).  Here's what to order:

OK, I've got my hardware, now what?
    First of all, you should read the Starter Package Manual.  Follow the instructions for checking out your hardware setup, and make sure you can get the demo program to display its menu in your terminal window.  This will assure you that your power supply, communications, and PC are all set up correctly.

How do I use the Quad Motor Driver Module?
    This module has four H-bridge circuits and some simple logic.  It is capable of driving four DC motors or two bipolar stepper motors (one channel per winding).  Each channel is controlled by an enable signal and a direction signal.  The direction signal controls the direction of the current through the winding.  Since there are four channels, eight output port lines are required to drive them. The default port line assignments are: PORTA bits PA3 - PA6 and PORTD bits PD2 - PD5.  These port pins are connected from the 26-pin connector to the motor driver circuits via small removable wire links if for some reason you wish to re-assign the port pin functions.
    Check your motor driver board by downloading the dual stepper motor demo program mentioned on the MicroCore-11 Accessories page (available at http://www.technologicalarts.com/myfiles/files/mc11dsm.zip ).  Before hooking up any motors, apply voltage to the stack of boards by attaching the red & black power cable to J1 of the MicroCore-11 module.  The voltage regulator on MicroCore-11 supplies the required 5V for both the boards at this point in the test.  Download the Stepper Motor test program into the boards memory, and then switch to PROT and RUN.  Press RESET, and you should see all red and green LEDs on the motor board flickering rapidly (you may have to move your eyes--  or the boards-- quickly to see the flickering).  This indicates everything is working properly.
    Now, disconnect power and remove the MicroCore-11 board from the stack.  Cut the W1 jumper on the motor driver board, so that its on-board voltage regulator will not be sending 5V to the other board through the 26-pin connector (each board has its own 5V regulator).
    If you're new to stepper motors, be sure to browse through the links on our Application webpage for a wealth of information to get you up to speed (pardon the pun ;-).
    Each stepper motor has two windings (ie. four wires).  Identify which two wires are for each winding (by using an Ohmmeter, for example).  Making sure the power is off, attach one winding to each terminal block on on one side of the Quad Motor Driver Module.  Then connect the two windings of the other stepper motor to the two terminal blocks on the opposite edge of the board, tightening the screws securely.  Then replace the MicroCore-11 board on top of the stack.
    You're about to apply power to the motors, so make sure they are oriented in such a way that they won't do any damage when the shafts suddenly start turning.  Make sure that the power you supply to J1 of the motor driver board is the correct voltage necessary to run the stepper motors (eg. use a 9V supply if you are using 9V stepper motors).  Of course the voltage has to be at least 5V, or the regulators and the MicroCore-11 board won't work.  Using the two red & black power wires supplied, apply power to both boards.  Once power is applied, the motor shafts should begin turning or vibrating.  If the shaft turns steadily, you have the winding connections correct.  If it is jerky or stalls, then you have the winding sequence incorrect.  Carefully loosen one winding at a time from the terminal block, and reverse the winding connections until you find the proper sequence that makes the motor shaft run smoothly.  Be careful not to let the free end of the wire touch anything on the circuit board, or you might blow something out.  Make a note of this wiring configuration so you don't have to go through this phase of testing again.

Tips for using ICC11 (v4.5 shown)...

• always include the file vectors.c.  If there are no vectors, the MCU will never even start executing your code (because it always needs a reset vector to point to the start of your program).

• You must set up the linker options (under COMPILER).  You can use the SETUP WIZARD (select upper 32K ROM/ lower 32K RAM).  This gives the linker settings:

• 0x8000 for TEXT
• 0x1400 for DATA
• 0xfff for stack
• When you've got some C code written, select COMPILE TO EXECUTABLE, set the TERMINAL for BOOTSTRAP DOWNLOAD MODE, select BOOTSTRAP OPTIONS to EXTERNAL EEPROM and NORMAL Then download the .s19 file to MicroCore, after resetting the board with the switch settings at BOOT and WRITE

• try the hello.c program first--  if you can't get it to work, then there's no point struggling with your own program yet
• If you are using "canned" motor driver software (eg. the miniboard motor routines), you should first check to see if the routines are using some other port lines instead of the ones connected for the motor driver board you have.  MicroCore-11 does not have ports B and C, so any code that manipulates these ports will have no effect.  Remember, too, that your second stepper motor will be using PORTD lines, so it will need to be different than the ones driving your first motor. You'll have to modifiy the code accordingly.

• MicroCore-11 Quad Motor Driver Module Schematic
• Data Sheet for SN754410 1 Amp Dual H-bridge Chip
• Application Note (126K) Using the MicroCore11 Motor Driver Module

• Stepper Motor Driver Software Example
• DC Motor Driver Demo Software
• MiniBoard C Libraries
• MicroCore-11 Demo Program (C version)