/* //////////////////////////////////////////////////////////////////////////// Handy Macros //////////////////////////////////////////////////////////////////////////// */ #define set_motor(X) P1 = (P1 & 0xC0) | X /* Set the motor control lines without messing up the other two bits of Port 1 */ /* //////////////////////////////////////////////////////////////////////////// Local Function Prototypes //////////////////////////////////////////////////////////////////////////// */ void step_the_motor(signed char); /* //////////////////////////////////////////////////////////////////////////// Module Variables //////////////////////////////////////////////////////////////////////////// */ /* These macros correlate the L6219 signal names with their positions within Port 1. Note that here we call the two windings 'A' and 'B' instead of '1' and '2' like the data sheet does. */ #define A_I0 0x01 /* Hardware dependent */ #define A_I1 0x02 /* Hardware dependent */ #define A_Ph 0x04 /* Hardware dependent */ #define B_I0 0x20 /* Hardware dependent */ #define B_I1 0x10 /* Hardware dependent */ #define B_Ph 0x08 /* Hardware dependent */ /* These macros give names to the various possible settings of the current control signals. The numbers in the names indicate percent of full current. */ #define A_0 (A_I0 | A_I1) #define A_33 A_I1 #define A_67 A_I0 #define A_100 0 #define B_0 (B_I0 | B_I1) #define B_33 B_I1 #define B_67 B_I0 #define B_100 0 /* These macros give names to the directions of current flow in the two windings. */ #define A_PLUS A_Ph #define A_MINUS 0 #define B_PLUS B_Ph #define B_MINUS 0 /* This table specifies the sequencing of the I/O lines needed to make the motor move. See the data sheet for the L6219 motor driver for details. */ #if STEP_FULL /* Full stepping with 100% current */ static code char sequence[] = { A_MINUS | A_100 | B_MINUS | B_100, A_PLUS | A_100 | B_MINUS | B_100, A_PLUS | A_100 | B_PLUS | B_100, A_MINUS | A_100 | B_PLUS | B_100 }; #endif #if STEP_HALF /* Half stepping with 67% current */ static code char sequence[] = { A_MINUS | A_0 | B_PLUS | B_67, A_PLUS | A_67 | B_PLUS | B_67, A_PLUS | A_67 | B_PLUS | B_0, A_PLUS | A_67 | B_MINUS | B_67, A_PLUS | A_0 | B_MINUS | B_67, A_MINUS | A_67 | B_MINUS | B_67, A_MINUS | A_67 | B_MINUS | B_0, A_MINUS | A_67 | B_PLUS | B_67 }; #endif #if STEP_QUARTER /* Quarter stepping with 67% current */ static code char sequence[] = { A_MINUS | A_0 | B_PLUS | B_67, A_PLUS | A_33 | B_PLUS | B_67, A_PLUS | A_67 | B_PLUS | B_67, A_PLUS | A_67 | B_PLUS | B_33, A_PLUS | A_67 | B_PLUS | B_0, A_PLUS | A_67 | B_MINUS | B_33, A_PLUS | A_67 | B_MINUS | B_67, A_PLUS | A_33 | B_MINUS | B_67, A_PLUS | A_0 | B_MINUS | B_67, A_MINUS | A_33 | B_MINUS | B_67, A_MINUS | A_67 | B_MINUS | B_67, A_MINUS | A_67 | B_MINUS | B_33, A_MINUS | A_67 | B_MINUS | B_0, A_MINUS | A_67 | B_PLUS | B_33, A_MINUS | A_67 | B_PLUS | B_67, A_MINUS | A_33 | B_PLUS | B_67 }; #endif #if STEP_SIXTH /* Sixth stepping with 100% current */ static code char sequence[] = { A_MINUS | A_0 | B_PLUS | B_100, A_PLUS | A_33 | B_PLUS | B_100, A_PLUS | A_67 | B_PLUS | B_100, A_PLUS | A_100 | B_PLUS | B_100, A_PLUS | A_100 | B_PLUS | B_67, A_PLUS | A_100 | B_PLUS | B_33, A_PLUS | A_100 | B_PLUS | B_0, A_PLUS | A_100 | B_MINUS | B_33, A_PLUS | A_100 | B_MINUS | B_67, A_PLUS | A_100 | B_MINUS | B_100, A_PLUS | A_67 | B_MINUS | B_100, A_PLUS | A_33 | B_MINUS | B_100, A_PLUS | A_0 | B_MINUS | B_100, A_MINUS | A_33 | B_MINUS | B_100, A_MINUS | A_67 | B_MINUS | B_100, A_MINUS | A_100 | B_MINUS | B_100, A_MINUS | A_100 | B_MINUS | B_67, A_MINUS | A_100 | B_MINUS | B_33, A_MINUS | A_100 | B_MINUS | B_0, A_MINUS | A_100 | B_PLUS | B_33, A_MINUS | A_100 | B_PLUS | B_67, A_MINUS | A_100 | B_PLUS | B_100, A_MINUS | A_33 | B_PLUS | B_100, A_MINUS | A_67 | B_PLUS | B_100 }; #endif /* //////////////////////////////////////////////////////////////////////////// step_the_motor() /////////////////////////////////////////////////////////////////////////////// DESCRIPTION: This function moves the motor by one step in the specified direction. NOTE: A "step" is a full motor step (1.8°) if STEP_FULL is 1, or a half step (0.9°) if STEP_HALF is 1, or a quarter step (0.45°) if STEP_QUARTER is 1. REVISIONS: 31 Jul 06 - RAC - Genesis //////////////////////////////////////////////////////////////////////////// */ void step_the_motor(signed char inc) { static signed char index; /* Sequence table index */ index += inc; /* Bump sequence table index */ #if STEP_FULL index &= 0x03; /* Wrap at end of table */ #endif #if STEP_HALF index &= 0x07; /* Wrap at end of table */ #endif #if STEP_QUARTER index &= 0x0F; /* Wrap at end of table */ #endif #if STEP_SIXTH if (index > 23) index = 0; /* Wrap at end of table */ if (index < 0) index = 23; /* Wrap at end of table */ #endif set_motor(sequence[index]); /* Apply new pattern */ } /* End step_the_motor() */