This semester I had my first microcontrollers class and cant seem to get enough of it. For the classes final project my professor gave each student the choice between 4 different projects. I decided that I wanted to go through and do them all for practice. The program that I am working on takes a string of ASCII characters and sends them over the SCI and converts it to morse code. The following code is what I have done so far but I am having trouble with the last ISR and dont really have a clue how to do what the instructions says. The part I am confused about is under the line of asterisks.
Any help would be appreciated. Thanks!
Any help would be appreciated. Thanks!
Rich (BB code):
#include <hidef.h> /* for EnableInterrupts macro */
#include "mc9s08qg8.h" /* include peripheral declarations */
#define RBUFSIZ 80
#define BAUD 9600
#define SCIBDVAL (1000000+BAUD)/(2*BAUD)
#define INITIAL_UNIT 25
#define Morse_Unit 25
extern unsigned const char morsecode[];
static unsigned char UnitDelay=INITIAL_UNIT, UnitCountDown=INITIAL_UNIT;
static unsigned char MorseState=0;
static unsigned char rcvbuff[RBUFSIZ] = "hello there";
static unsigned char *rcviptr, *rcvoptr; // my code
static unsigned char chara;
static unsigned char codechar;
void main(void) {
unsigned int i;
SOPT1 = SOPT1_BKGDPE_MASK+SOPT1_RSTPE_MASK;
PTAPE = 0xff;
PTBDD = 0xff;
ICSTRM = NV_ICSTRM;
for (i=0;i<400;i++); /* delay 2 ms (at 4 MHz) */
ICSC2 = 0; /* up speed to 8 MHz */
PTADD_PTADD0 = 1; /* set pin 16 as an output */
PTADS_PTADS0 = 1; /* make capable of driving LEDs */
SCIBD = SCIBDVAL;
SCIC2 = SCIC2_RE_MASK+SCIC2_RIE_MASK;
/* Correctly complete these 2 lines to produce 250 TOF interrupts per sec */
MTIMSC = 0b01010000;
MTIMMOD = 249;
/* The following configures TPM Channel 0 to toggle pin 16 */
TPMC0SC = 0x14;
/* The defalult for all other registers is okay except */
/* the modulo register sets the frequency of the tone produced */
/* on pin 16 according to the formula: freq = 8000000/(2*(TPMMOD+1)) */
TPMMOD = 300; /* pick a value for a freq between 500-2000 */
rcvoptr = rcvbuff;
rcviptr = rcvbuff+11; /* "hello there" is in buff */
EnableInterrupts; /* enable interrupts */
for(;;); /* loop forever leaving all work to the ISRs */
}
interrupt VectorNumber_Vmtim void mtimisr() {
static unsigned char charcode;
MTIMSC_TOF = 0;
if (--UnitCountDown==0)
{
UnitCountDown = Morse_Unit; // default delay will be 1
switch (MorseState)
{
case 0:
if (rcvoptr != rcviptr)
{
chara = *rcvoptr++;
if (rcvoptr > rcvbuff+RBUFSIZ)
rcvoptr = rcvbuff;
if (chara ==' '){
{UnitCountDown = 3*Morse_Unit; break;}
codechar = (unsigned char)morsecode[chara];
startsound();
MorseState=1;
}
if (codechar & 0x80==0x80)
/*most significant bit of codechar is 1*/
UnitCountDown = 3*Morse_Unit; //UnitCoundDown changed from MorseCountDown
break;
case 1:
/*insert code to stop sound and advance to state 2*/
stopsound();
MorseState = 2;
break;
case 2:
/* the code here first shifts codechar one bit left */
codechar = (codechar << 1);
/* then it checks if it is 0x80 indicating char complete */
if(codechar = 0x80)
MorseState = 0;
/* follow the state arrow indicated from the above result */
/* if char not complete code is a copy of the four lines */
/* starting with startsound() from state 0 above */
else{
startsound();
MorseState = 1;
}
if ((codechar & 0x80)==0x80){
UnitCountDown = 3*Morse_Unit;
}
break;
}
}
}
}
void startsound() {
/* add code to start sound by starting TPMCNT counting
by setting the the CLKSA bit in TPMSC. This selects
the bus clock as the clock for the counter. */
TPMSC_CLKSA = 1;
}
void stopsound() {
/* add code to stop sound (clear CLKSA which selects nothing
as the clock for the counter thus disabling it */
TPMSC_CLKSA = 0;
}
interrupt 15 void scirisr() {
static unsigned char charb;
charb = SCIS1;
charb = SCID;
//*********************************************************
//This part below is what I am having Trouble with.
/* test to see if the character is one of any special characters you picked */
/* to vary the speed or tone frequency of the Morse code being produced */
/* if it is do the specified change. The speed is modified by changing the */
/* value of MorseUnit. The freq of the tone is modified by changing TMPMOD. */
/* if not command char, place SCID value in the circular receive buffer */
}
/* complete the constant table below */
unsigned const char morsecode[] =
{0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
0x80,0,0,0,0x13,0,0,0, /* sp - - - $ - - - */
0,0,0,0,0xce,0,0x56,0, /* - - - - , - . - */
0xfc,0x7c,0x3c,0x1c,0x0c,0x04,0x84,0xc4, /* 0 1 2 3 4 5 6 7 */
0xe4,0xf4,0xe2,0xaa,0x00,0x00,0x00,0x32, /* 8 9 : ; - - - ? */
0x00,0x60,0x88,0xa8,0x90,0x40,0x28,0xd0, /* - A B C D E F G */
0x08, 0x20, ox78, 0xb0, 0x98, 0xe0, 0xa0, /* H,J,K,L,M,N,O*/
0xf0,0x98,0xb8,0xc8,0,0,0,0,0, /* X Y Z - - - - - */
0x00,0x60,0x88,0xa8,0x90,0x40,0x28,0xd0, /* - a b c d e f g */
0x68, 0xd8, 0x50, 0x10, 0xc0, 0xc0, 0x30, /*p, q, r,s,t,u,v*/
0x18, 0x60,0x98,0xb8,0xc8,0,0,0,0,0}; /* x y z - - - - - */
/* end of source file */
