dsPIC Tutorial 3-Đọc ngõ vào và giao tiếp LCD

[silvadk2]

uh, mình hiểu rồi, cảm ơn bạn nha !

[harakiri]

Mình viết đoạn code này để xuất một chuỗi kí tự và số lên trên máy tính, quá trình truyền là ok. Tuy nhiên, khi dùng hàm delay_us hay delay_ms qua trình truyền lại không xảy ra.
Đây là code :


#include<p33fj256gp710.h>
#include<stdio.h>
_FOSCSEL(FNOSC_FRC); // Internal FRC oscillator
_FOSC(FCKSM_CSECMD & OSCIOFNC_OFF & POSCMD_NONE);
// Clock Switching is enabled and Fail Safe Clock Monitor is disabled
// OSC2 Pin Function: OSC2 is Clock Output
// Primary Oscillator Mode: XT Crystal

//unsigned int a,b,c,d;
#define ms_count 125 ;
unsigned int time_out,m,x,y;
unsigned char sbuf[200],c='C',t='T';

void __attribute__ ((interrupt, no_auto_psv)) _U1RXInterrupt(void) {
LATA = U1RXREG;
IFS0bits.U1RXIF = 0; //interrupt request has not occurred
}
void __attribute__ ((interrupt, no_auto_psv)) _U1TXInterrupt(void) {
IFS0bits.U1TXIF = 0;
}

void InitClock() {
PLLFBD = 38; // M = 40
CLKDIVbits.PLLPOST = 0; // N1 = 2
CLKDIVbits.PLLPRE = 0; // N2 = 2
OSCTUN = 0;//khong su dung oscillator tuning register
RCONbits.SWDTEN = 0; // disabe watch dog timer

// Clock switch to incorporate PLL
__builtin_write_OSCCONH(0x01); // Initiate Clock Switch to FRC with PLL (NOSC=0b001)
// luu y : doc thanh ghi OSCCON de thay
__builtin_write_OSCCONL(0x01); // Start clock switching
//ghi lan luot vao 8 bit cao va thap cua OSCCON
while (OSCCONbits.COSC != 0b001); // Wait for Clock switch to occur

while(OSCCONbits.LOCK != 1) {}; //pll lock status bit
}

void InitUART1() {

// configure U2MODE
U1MODEbits.UARTEN = 0; // Bit15 TX, RX DISABLED, ENABLE at end of func
//U2MODEbits.notimplemented; // Bit14
U1MODEbits.USIDL = 0; // Bit13 Continue in Idle
U1MODEbits.IREN = 0; // Bit12 No IR translation
U1MODEbits.RTSMD = 0; // Bit11 Simplex Mode
//U1MODEbits.notimplemented; // Bit10
U1MODEbits.UEN = 0; // Bits8,9 TX,RX enabled, CTS,RTS not
U1MODEbits.WAKE = 0; // Bit7 No Wake up (since we don't sleep here)
U1MODEbits.LPBACK = 0; // Bit6 No Loop Back
U1MODEbits.ABAUD = 0; // Bit5 No Autobaud (would require sending '55')
U1MODEbits.URXINV = 0; // Bit4 IdleState = 1 (for dsPIC)
U1MODEbits.BRGH = 0; // Bit3 16 clocks per bit period
U1MODEbits.PDSEL = 0; // Bits1,2 8bit, No Parity
U1MODEbits.STSEL = 0; // Bit0 One Stop Bit

// Baud Rate Generator is for 9600.
// See section 19.3.1 of datasheet.
// U1BRG = (Fcy/(16*BaudRate))-1
// U1BRG = (37M/(16*9600))-1
// U1BRG = 240
U1BRG = 239; // 40Mhz osc, 9600 Baud, baud rate = Fcy/[16x(UxBRG+1)]

// Load all values in for U1STA SFR
U1STAbits.UTXISEL1 = 0; //Bit15 Int when Char is transferred (1/2 config!)
U1STAbits.UTXINV = 0; //Bit14 N/A, IRDA config
U1STAbits.UTXISEL0 = 0; //Bit13 Other half of Bit15
//U2STAbits.notimplemented = 0; //Bit12
U1STAbits.UTXBRK = 0; //Bit11 Disabled
U1STAbits.UTXEN = 0; //Bit10 TX pins controlled by periph
U1STAbits.UTXBF = 0; //Bit9 *Read Only Bit*
U1STAbits.TRMT = 0; //Bit8 *Read Only bit*
U1STAbits.URXISEL = 0; //Bits6,7 Int. on character recieved
U1STAbits.ADDEN = 0; //Bit5 Address Detect Disabled
U1STAbits.RIDLE = 0; //Bit4 *Read Only Bit*
U1STAbits.PERR = 0; //Bit3 *Read Only Bit*
U1STAbits.FERR = 0; //Bit2 *Read Only Bit*
U1STAbits.OERR = 0; //Bit1 *Read Only Bit*
U1STAbits.URXDA = 0; //Bit0 *Read Only Bit*

IPC7 = 0x4400; // Mid Range Interrupt Priority level, no urgent reason

IFS0bits.U1TXIF = 0; // Clear the Transmit Interrupt Flag
IEC0bits.U1TXIE = 1; // Enable Transmit Interrupts
IFS0bits.U1RXIF = 0; // Clear the Recieve Interrupt Flag
IEC0bits.U1RXIE = 1; // Enable Recieve Interrupts

U1MODEbits.UARTEN = 1; // And turn the peripheral on

U1STAbits.UTXEN = 1;

}


int main(void) {

InitClock(); // This is the PLL settings

InitUART1(); // Initialize UART2 for 9600,8,N,1 TX/RX

while(1){ // The ever versatile Infinite Loop!

sprintf(sbuf,"%c%c %i %i %i %i %i %i \n",'T','C',20,40,40,60,30,10);
putsUART1(sbuf);

}
}
/************************************************** *************************
* Function Name : putsUART1 *
* Description : This function puts the data string to be transmitted *
* into the transmit buffer (till NULL character) *
* Parameters : unsigned int * address of the string buffer to be *
* transmitted *
* Return Value : None *
************************************************** *************************/

void putsUART1(unsigned int *buffer)
{
char * temp_ptr = (char *) buffer;

/* transmit till NULL character is encountered */

if(U1MODEbits.PDSEL == 3) /* check if TX is 8bits or 9bits */
{
while(*buffer != '\0')
{
while(U1STAbits.UTXBF); /* wait if the buffer is full */

U1TXREG = *buffer++; /* transfer data word to TX reg */
delay_us(100);
}
}
else
{
while(*temp_ptr != '\0')
{
while(U1STAbits.UTXBF); /* wait if the buffer is full */

U1TXREG = *temp_ptr++; /* transfer data byte to TX reg */
delay_us(100);
}
}
}
/************************************************** *****************************************
//Function: void Init_TMR1(void)
//Input: None
//Output: Setup Parameter to Timer1 Operate
// TMR1 use for delay
************************************************** *****************************************/
void Init_TMR1(void)
{
T1CONbits.TON=0; //Stop Timer1
T1CONbits.TGATE=0; //Disable Gated Timer mode
T1CONbits.TCKPS=2; //Select Prescale 1:1
T1CONbits.TCS=0; //Internal clock
PR1=ms_count;
_T1IF=0;
_T1IE=1;
TMR1=0;
}
/************************************************** *****************************************
//Function: void delay_us(unsigned int n)
//Input: n: n us to delay
//Output: Delay n us
************************************************** *****************************************/
void delay_us(unsigned int n)
{
PR1=n*ms_count;
time_out=0;
T1CONbits.TON=1;
while(time_out==0);
T1CONbits.TON = 0;
TMR1=0;
}
/************************************************** *****************************************
//Function: void delay_ms(unsigned int n)
//Input: n: n ms to delay
//Output: Delay n ms
************************************************** *****************************************/
void delay_ms(unsigned int n)
{
unsigned int i;
i=0;
while(i<=n)
{
delay_us(1000);
i++;
}
}
void _ISR _T1Interrupt(void)
{
_T1IF = 0; //Clear Timer1 flag
time_out = 1;
}

[namqn]

Nguyên văn bởi harakiri

Mình viết đoạn code này để xuất một chuỗi kí tự và số lên trên máy tính, quá trình truyền là ok. Tuy nhiên, khi dùng hàm delay_us hay delay_ms qua trình truyền lại không xảy ra.
Đây là code :
...

Có vẻ bạn áp dụng một cách máy móc kỹ thuật delay dùng Timer 1 trong tutorial mà không hiểu về nó. Có chắc đoạn code delay_us(n) sẽ làm trễ n micro giây không?

Bạn có hàm Init_TMR1() trong source code, nhưng không hề gọi nó trong main(), vậy Timer 1 sẽ được thiết lập ra sao?

Thân,