unsigned char frequencyrange(void)
{
unsigned char m;// represent adc convert value
unsigned int f;// represent frequency
char msg1[16] = " START NOW? ";//LCD LINE 1 message
char msg2[16] = " PRESS ANYKEY ";// LCD line 2 message
LCD_Reset();// initiliaze LCD
sprintf(msg1," Please choose ");// chose frequency message
LCD_Line1(msg1);
sprintf(msg2,"Frequency");
LCD_Line2(msg2);
Delay10KTCYx(250);// delay 0.25s
Delay10KTCYx(250);//delay 0.25s
Delay10KTCYx(250);// delay0.25s
Delay10KTCYx(250);//delay0.25s
LCD_Reset();// initialize lCD
switch(bo)
{
case 1:
do
{
sprintf(msg1,"Range:11~2277 Hz");
LCD_Line1(msg1);
m=poten(8);// ADC convert value
if (m==0) m=1;// let the least ADC value is 1
f=(unsigned int)1/(1/12600+m*0.00035+0.000089);;// caculate sine wave frequency
if ((m<=60)&&(m>=30))f=f-1;// slightly adjust frequency
if ((m<=20)&&(m>=10))f=f-4;// slightly adjust frequency
if ((m>5)&&(m<10) )f=f-5;// slightly adjust frequency
if(m==5) f=f-6;// slightly adjust frequency
if(m==4) f=f-7;// slightly adjust frequency
if(m==3) f=f-7;// slightly adjust frequency
if (m==2) f=f+13;// slightly adjust frequency
sprintf(msg2,"%10d Hz",f);
LCD_Line2(msg2);// show frequency
if (SWITCH_1==0)
{
switch_release();//wait for RA5 release
return 2;// if RA5 pressed goto wavetype function
}
}
while(SWITCH_0 == 1);
switch_release();//wait for RB0 release
sinewave(m);//output sine wave
switch_release();//wait for RA5 release
return 3;// if RA5 pressed goto frequency range function
break;
case 2:
do
{
sprintf(msg1,"Range:6~581 Hz");
LCD_Line1(msg1);
m=poten(8);// ADC convert value
if (m==0) m=1;// let the least ADC value is 1
f=(unsigned int) 1/ (1/847 + m*0.00057+0.001230); //caculate and slightly adjust triangle wave frequency
if (m==1) f=f+26;//caculate and slightly adjust triangle wave frequency
if (m==2) f=f+20;//caculate and slightly adjust triangle wave frequency
if (m==3) f=f+12;//caculate and slightly adjust triangle wave frequency
if (m==4) f=f+10;//caculate and slightly adjust triangle wave frequency
if (m==5) f=f+7;//caculate and slightly adjust triangle wave frequency
if ((m>=6)&&(m<=8)) f=f+5;//caculate and slightly adjust triangle wave frequency
if (m==9) f=f+4;//caculate and slightly adjust triangle wave frequency
if ((m>=10)&& (m<=13)) f=f+3;//caculate and slightly adjust triangle wave frequency
if ((m>=13)&&(m<=17)) f=f+2;//caculate and slightly adjust triangle wave frequency
if ((m>=18)&&(m<=50)) f=f+1;//caculate and slightly adjust triangle wave frequency
sprintf(msg2,"%10d Hz",f);
LCD_Line2(msg2);// show frequency
if (SWITCH_1==0)
{
switch_release();//wait for RA5 release
return 2;// if RA5 pressed goto wavetype function
}
}
while(SWITCH_0 == 1);
switch_release();//wait for RB0 release
triwave(m);// output triangle wave
switch_release();//wait for RA5 release
return 3;// if RA5 pressed goto frequency range function
break;
case 3:
do
{
sprintf(msg1,"Range:5~676 Hz");
LCD_Line1(msg1);
m=poten(8);// ADC convert value
if (m<=1) m=2;// let the least ADC value is 2
f=(unsigned int) 1/ (1/15600 + m*0.000709+0.00007);//caculate sawtooth wave frequency
if ((m==2)||(m==3)) f=f+4;//caculate and slightly adjust sawtooth wave frequency
if (m==4) f=f+1;//caculate and slightly adjust sawtooth wave frequency
sprintf(msg2,"%10d Hz",f);
LCD_Line2(msg2);// show frequency
if (SWITCH_1==0)
{
switch_release();//wait for RA5 release
return 2;// if RA5 pressed goto wavetype function
}
}
while(SWITCH_0 == 1);
switch_release();//wait for RB0 release
sawtooth(m);//output sawtooth wave
switch_release();//wait for RA5 release
return 3;// if RA5 pressed goto frequency range function
break;
case 4:
do
{
sprintf(msg1,"Range:102~7690Hz");
LCD_Line1(msg1);
m=poten(8);// adc convert value
if (m==0) m=1;// let the least ADC value is 1
if ((m>=140)&&(m<=255)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-0.5;//caculate and slightly adjust square wave frequency
if ((m>=101)&&(m<=139)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-1.5;//caculate and slightly adjust square wave frequency
if ((m>=70)&&(m<=100)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-2.5;//caculate and slightly adjust square wave frequency
if ((m>=64)&&(m<=69)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-3.5;//caculate and slightly adjust square wave frequency
if ((m>=55)&&(m<=63)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-4.5;//caculate and slightly adjust square wave frequency
if ((m>=46)&&(m<=54)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-5.5;//caculate and slightly adjust square wave frequency
if ((m>=45)&&(m<=43)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-6.5;//caculate and slightly adjust square wave frequency
if ((m>=40)&&(m<=42)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-7.5;//caculate and slightly adjust square wave frequency
if ((m>=30)&&(m<=40)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-9.5;//caculate and slightly adjust square wave frequency
if ((m>=20)&&(m<=29)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-11.5;//caculate and slightly adjust square wave frequency
if ((m>=10)&&(m<=19)) f=(unsigned int) 1/ (1/11400 + m*0.0000376+0.000075)-2.5*m;//caculate and slightly adjust square wave frequency
if (m==10) f=2131;//caculate and slightly adjust square wave frequency
if (m==9) f=2313;//caculate and slightly adjust square wave frequency
if (m==8) f=2540;//caculate and slightly adjust square wave frequency
if (m==7) f=2810;//caculate and slightly adjust square wave frequency
if (m==6) f=3140;//caculate and slightly adjust square wave frequency
if (m==5) f=3570;//caculate and slightly adjust square wave frequency
if (m==4) f=4130;//caculate and slightly adjust square wave frequency
if (m==3) f=4900;//caculate and slightly adjust square wave frequency
if (m==2) f=6020;//caculate and slightly adjust square wave frequency
if (m==1) f=7690; //caculate and slightly adjust square wave frequency
sprintf(msg2,"%10d Hz",f);
LCD_Line2(msg2);// show frequency
if (SWITCH_1==0)
{
switch_release();//wait for RA5 release
return 2;// if RA5 pressed goto wavetype function
}
}
while(SWITCH_0 == 1);
switch_release();//wait for RB0 release
squarewave(m);//output square wave
switch_release();//wait for RA5 release
return 3;// if RA5 pressed goto frequency range function
break;
default:
break;
}
}
void sample(int frequency) {
int samples_per_period = SAMPLE_RATE / frequency;
squarewave(samples_per_period);
}