//
// adproj.c Analog to Digital test program for the 
//          68HC12.
//
// This file is written using Imagecraft's icc12 
// compiler. 
//
// Written as part of an Encoder article for the
// seattle robotics society. See www.seattlerobotics.org
// for details.
//


#include <stdio.h>
#include <hc12.h>

#define TRUE -1
#define FALSE 0


int g_CurrentChannel;
int g_CurrentValue;

void InitializeSystem()
{
    // The 68HC12 COP (Watchdog timer) needs to be disabled
    COPCTL = 0;         // Turn of the COP
    
    // Turn on the serial port
    setbaud(13);        // Set to 19200 baud
    
    // Power up the A/D converter
    
    ATDCTL2 |= 0x80;
    
    // Turn on the TCNT timer
    TSCR |= 0x80;
    
    // Initialize global variables
    g_CurrentChannel = 0;
    
    g_CurrentValue = -1;
    
}


// Single channel scan returns the average A/D result for channel iChannel
int SingleChannelScan(int iChannel)
{
    int iSum = 0;
    int i;
    
    unsigned char *pADR = (unsigned char *)&(ADR0H);   
    
    if((iChannel < 0) || (iChannel > 7))
    {
        // Something bad has happened
       
        return -1;
    }
    //
	// Perform a single channel A/D read cycle. By setting the
	// S8CM bit, the single channel is sampled 8 times consecutively
	// The low 3 bits determine which channel is going to be sampled
	// and is derived from the argument passed to this function.
	//
	// The 8 results are stored in registers ADR0 thru ADR7
	//
	// This provides a quick way of grabbing an average value
	//
	// Writing to ATDCTL5 will initiate the conversion
	
	ATDCTL5 = 0x40 + iChannel;
	
	// Now we wait for the SCF (Sequence Complete Flag) of ATSTAT to be
	// set. When it is set, then the result registers are valid
	
	while( !(ATDSTAT & 0x8000));
	
	// The results are now in ADR0 thru ADR7. ADR0 thru ADR7 are 
	// aligned on word boundaries (70,72,74,76...), so we do some
	// extra math on the index
	
	for (i = 0 ; i < 8 ; i++)
	{
	   iSum += pADR[i<<1];
	}
	
	iSum = iSum >> 3;      // Divide sum by 8 to determine average
	
	return iSum;
	
}
void RunSingleChannelTest(int iChannel)
{
    char ch;
    int iNewValue;
    
    iNewValue = SingleChannelScan(iChannel);
    
    // Report the changed value
    printf("(%x) Single Channel 0x%x: 0x%x\n",TCNT,iChannel,iNewValue);
              
}
void RunMultiChannelTest()
{
    int i;
    unsigned char *pResult = (unsigned char *) &(ADR0H);
    
    printf("(%x) Multi Channel Scan \n",TCNT);
    
    // Put the A/D converter into SC8M | MULT and let it rip
    
    ATDCTL5 = 0x50;
	
	// Now we wait for the SCF (Sequence Complete Flag) of ATSTAT to be
	// set. When it is set, then the result registers are valid
	
	while( !(ATDSTAT & 0x8000));
	
	//
	// Print out the results
	//
	for(i=0;i<8;i++)
	{
	   printf("Channel %u = 0x%x\n",i,pResult[i<<1]);
	}
	return ; 
	
}
//
// The idea being this program is simple. On the RS-232 line, just press
// the numeric key of the channel you wish to sample. To get all of the
// channels using Multi-channel mode, press 'm'
//
void main()
{
    

	int ch;

    InitializeSystem();
    printf("adproj started\n");
    for(;;)
    {
        ch = getchar();
        printf("ch = %x '%c'\n",ch,ch);
        
        switch(ch)
        {
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        {
            RunSingleChannelTest(ch - '0');
            break;
        }
        case 'm':
        {
            RunMultiChannelTest();
            break;
        }
        default:
            printf("Press number (0-7) for single channel\n");
            printf("Press 'm' for multi-channel\n");
        
        }
 

    }
}

/* As is, all interrupts except reset jumps to 0xffff, which is most
 * likely not going to useful. To replace an entry, declare your function,
 * and then change the corresponding entry in the table. For example,
 * if you have a SCI handler (which must be defined with
 * #pragma interrupt_handler ...) then in this file:
 * add
 *	extern void SCIHandler();
 * before th table.
 * In the SCI entry, change:
 *	DUMMY_ENTRY,
 * to
 *  SCIHandler,
 */
extern void _start();	/* entry point in crt??.s */

#define DUMMY_ENTRY	(void (*)())0xFFFF

#pragma abs_address:0xffd0

/* change the above address if your vector starts elsewhere
 */
void (*interrupt_vectors[])() =
	{
	/* to cast a constant, say 0xb600, use
	   (void (*)())0xb600
	 */

	DUMMY_ENTRY,	/* BDLC */
	DUMMY_ENTRY,	/* ATD */
	DUMMY_ENTRY,	/* RESERVED */
	DUMMY_ENTRY,	/* SCI */
	DUMMY_ENTRY,	/* SPI */
	DUMMY_ENTRY,	/* PAIE */
	DUMMY_ENTRY,	/* PAO */
	DUMMY_ENTRY,	/* TOF */
	DUMMY_ENTRY,	/* TOC5 */	/* HC12 TC7 */
	DUMMY_ENTRY,	/* TOC4 */	/* TC6 */
	DUMMY_ENTRY,	/* TOC3 */	/* TC5 */
	DUMMY_ENTRY,	/* TOC2 */	/* TC4 */
	DUMMY_ENTRY,	/* TOC1 */	/* TC3 */
	DUMMY_ENTRY,	/* TIC3 */	/* TC2 */
	DUMMY_ENTRY,	/* TIC2 */	/* TC1 */
	DUMMY_ENTRY,	/* TIC1 */	/* TC0 */
	DUMMY_ENTRY,	/* RTI */
	DUMMY_ENTRY,	/* IRQ */
	DUMMY_ENTRY,	/* XIRQ */
	DUMMY_ENTRY,	/* SWI */
	DUMMY_ENTRY,	/* ILLOP */
	DUMMY_ENTRY,	/* COP */
	DUMMY_ENTRY,	/* CLM */
	_start	/* RESET */
	};

#pragma end_abs_address

// End of file