技事新報

//
//
#include 
#include "adc10.h"
#include "timer.h"

// dsPic
// AN0   ---   audio signal in
// RE0   ---   -CS(mcp4922)
// RE1   ---   SCK(mcp4922)
// RE2   ---   SDI(mcp4922)
// RE3   ---   LDAC(mcp4922)
//
// Configuration bits--------------------------------------------------------
_FOSC(CSW_FSCM_OFF & FRC_PLL8);   //FRC with 8xPLL oscillator, Failsafe clock off
_FWDT(WDT_OFF);                  //Watchdog timer disabled
_FBORPOR(PBOR_OFF & MCLR_EN);    //Brown-out reset disabled, MCLR reset enabled
_FGS(CODE_PROT_OFF);             //Code protect disabled

// Setup Data for 10bits A/D Converter
// start by timer 3
unsigned int ValueADCON1 = ADC_MODULE_ON & 
                                              ADC_IDLE_STOP &                       
                                              ADC_FORMAT_SIGN_FRACT &
			                      ADC_CLK_TMR & 
                                              ADC_AUTO_SAMPLING_ON & 
                                              ADC_SAMPLE_INDIVIDUAL & 
			                      ADC_SAMP_OFF;
unsigned int ValueADCON2 = ADC_VREF_AVDD_AVSS & 
                                            ADC_SCAN_OFF &
                                            ADC_CONVERT_CH0 &
                                            ADC_SAMPLES_PER_INT_1 & 
                                            ADC_ALT_BUF_OFF & 
                                            ADC_ALT_INPUT_OFF;
unsigned int ValueADCON3 = ADC_SAMPLE_TIME_1 & 
                                            ADC_CONV_CLK_SYSTEM  &
                                            ADC_CONV_CLK_2Tcy;
unsigned int ValueADPCFG = ENABLE_AN0_ANA & 
                                            ENABLE_AN1_ANA & 
                                            ENABLE_AN2_ANA &
                                            ENABLE_AN3_ANA;
unsigned int ValueADCSSL = 0;
unsigned int Channel0 = ADC_CH0_POS_SAMPLEA_AN0 &                           
                                           DC_CH0_NEG_SAMPLEA_NVREF;

// variables
fractional SigIn;

// ADC割り込み処理
void _ISRFAST _ADCInterrupt(void)
{
	int d_in, d_out, i;
	
	IFS0bits.ADIF = 0;			

	SigIn = ReadADC10(0);	
  	
	d_in = ((0x8000 + SigIn)>>6) -512;
	// do something
  	d_out = 0x7000 | ((d_in + 512)<<2);
  	
  	LATEbits.LATE0 = 0;  //CS=0
  	for(i=0; i<16; i++){
    	     if(((d_out << i) & 0x8000) != 0){
      		LATEbits.LATE2 = 1;  //SDI=1
    	     }else{
      		LATEbits.LATE2 = 0;  //SDI=0
    	     }
    	     LATEbits.LATE1 = 1;  //SCK=1
    	     LATEbits.LATE1 = 0;  //SCK=0
  	}
  	LATEbits.LATE0 = 1;  //CS=1
  	LATEbits.LATE3 = 0;  //LDAC=0
  	LATEbits.LATE3 = 1;  //LDAC=0
}

//main-----------------------------------------------------------------------
int main(void)
{
	int i,j;
	
//Initialize
	LATE = 0x0000;	//

// Setup Port
	TRISB = 0x01;	//AN0 input
	TRISE = 0x00;	//all output
	
	SRbits.IPL=4;	//Set CPU priority Set core priority level to 4

// Setup ADC10		
	OpenADC10(ValueADCON1, 
                           ValueADCON2, 
                           ValueADCON3, 
                           ValueADPCFG, 
                           ValueADCSSL);
	SetChanADC10(Channel0);
	ConfigIntADC10(ADC_INT_PRI_7 & 
                                ADC_INT_ENABLE);

// Timer3 open　16kHz = (7.37MHz*8/4)/921
	OpenTimer3(T3_ON & T3_GATE_OFF & T3_PS_1_1 & T3_SOURCE_INT,921-1);

// init mcp4922
	LATEbits.LATE0 = 1;	//CS
	LATEbits.LATE1 = 0;	//SCK
	LATEbits.LATE2 = 0;	//SDI
	LATEbits.LATE3 = 1;	//LDAC

//Idle Loop
	while (1){};
}