. Em xem phần nguồn của con dsPIC cũng ko phát hiện gì cả.
. Em xem phần nguồn của con dsPIC cũng ko phát hiện gì cả.
.
namqn
void Init_ADC12(void)
{
//ADCON1 Register
//Set up A/D for Automatic Sampling
//Use Timer3 to provide sampling time
//Set up A/D conversrion results to be read in fractional
//number format.
//All other bits to their default state
ADCON1bits.FORM = 3; // luu du lieu dinh dang signed fractional 1.15
ADCON1bits.SSRC = 2; // dung timer3 de kich chuyen doi ADC
ADCON1bits.ASAM = 1; // cai dat che do tu dong lay mau
//ADCON2 Register
//Set up A/D for interrupting after 16 samples get filled in the buffer
//All other bits to their default state
ADCON2bits.SMPI = 15; // cai da che do ngat ADC sau khi day 16 mau trong bo dem du lieu
//ADCON3 Register
//We would like to set up a sampling rate of 8KHz
//Total Conversion Time= 1/Sampling Rate = 125 microseconds
//At 29.4 MIPS, Tcy = 33.9 ns = Instruction Cycle Time
//Tad > 667ns (for -40C to 125C temperature range)
//We will set up Sampling Time using Timer3 & Tad using ADCS<5:0> bits
//All other bits to their default state
//Let's set up ADCS arbitrarily to the maximum possible amount = 63
//So Tad = Tcy*(ADCS+1)/2 = 1.085 microseconds
//So, the A/D converter will take 14*Tad periods to convert each sample
ADCON3bits.ADCS = 63;
//Next, we will to set up Timer 3 to time-out every 125 microseconds
//As a result, the module will stop sampling and trigger a conversion
//on every Timer3 time-out, i.e., 125 microseconds. At that time,
//the conversion process starts and completes 14*Tad periods later.
//When the conversion completes, the module starts sampling again
//However, since Timer3 is already on and counting, about 110
//microseconds later (=125 microseconds - 14*Tad), Timer3 will expire
//again. Effectively, the module samples for 110 microseconds and
//converts for 15 microseconds
//NOTE: The actual sampling rate realized may be 7998.698 Hz
// due to a small round off error. Ensure you provide the
// true sampling rate to dsPICworks if you are trying to plot
// the sampled or filtered signal.
TMR3 = 0x0000;
PR3 = 0X0E65;
IFS0bits.T3IF = 0; // cho co ngat timer3=0
IEC0bits.T3IE = 0; // khong cho phep ngat timer3
//ADCHS Register
//Set up A/D Channel Select Register to convert AN7 on Mux A input
ADCHS = 0x000F; // chon AN15 la kenh thu du lieu analog
//ADCSSL Register
//Channel Scanning is disabled. All bits left to their default state
ADCSSL = 0x0000; // tat che do quet cac kenh. Cac n=bit con lai de che do mac dinh
//ADPCFG Register
//Set up channels AN15 as analog input and configure rest as digital
//Recall that we configured all A/D pins as digital when code execution
//entered main() out of reset
ADPCFG = 0xFFFF;
ADPCFGbits.PCFG15 = 0; //ngo AN15 la ngo vao analog
//Clear the A/D interrupt flag bit
IFS0bits.ADIF = 0; // xoa co ngat chuyen doi ADC
//Set the A/D interrupt enable bit
IEC0bits.ADIE = 1; // cho phep ngat ADC
//Turn on the A/D converter
//This is typically done after configuring other registers
ADCON1bits.ADON = 1; // bat dau cho do ADC hoat dong
//Start Timer 3
T3CONbits.TON = 1; // cho timer3 bat dau chay
}
void __attribute__((interrupt, no_auto_psv)) _ADCInterrupt(void)
{
IFS0bits.T3IF = 0; //Xoa co ngat timer3
unsigned int i = 0;
IFS0bits.ADIF = 0; //Xoa co ngat ADC
adcPtr=&ADCBUF0; // lay dia chi thanh ghi ADCBUF0 ghi vao thanh ghi adcPtr
for(i=0;i<=15;i++)
{
*iPtr++=*adcPtr++; //lay noi dung cua cac thanh ghi Buffer lan luot ghi vao cac bien
// inputsignal[]
}
if (iPtr>&inputsignal[159]) doFilterFlag=1; // thu duoc 160 mau thi vao xu ly
}
....
while(1)
{
while(!doFilterFlag){}; //Vong lap cho day 160 mau trong bo dem ADC
doFilterFlag=0; //chuan bi vong lap sau
(.....tính toán xử lý .........................)
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