// Serial communications example with MAX232R.
// using serial receive interrupt.
/* Задачата е да се изпрати от SerialPort Terminal през USART,някакъв предварително избран символ,
като например 'a'. Този символ да се присвои на PORTB и това да се индикира от LED1, който е
прикрепен към RB1.Задачката е проста за разбиращите,но аз съм начинаещ и нещо не ми се получава!
Използувам MPLAB IDE и C18 compiler.Кодът се компилира,минава през MPLAP SIM,но диодът не светва.
Опитвам да симулирам и чрез Proteus,но и там е същото.Вероятно имам проблем в кода,не не мога
да се справя сам!*/
//*****************************************************************************************************
#include <p18f2550.h>
#include <delays.h>
#include <usart.h>
/** CONFIGURATION ********************************************************************************************************/
#if defined(PIC18F2550_USB) // Configuration bits
#pragma config PLLDIV = 5 // (20 MHz crystal)
#pragma config CPUDIV = OSC1_PLL2
#pragma config USBDIV = 2 // Clock source from 96MHz PLL/2
#pragma config FOSC = HSPLL_HS
#pragma config FCMEN = OFF
#pragma config IESO = OFF
#pragma config PWRT = OFF
#pragma config BOR = ON
#pragma config BORV = 3
#pragma config VREGEN = ON // USB Voltage Regulator
#pragma config WDT = OFF
#pragma config WDTPS = 32768
#pragma config MCLRE = ON
#pragma config LPT1OSC = OFF
#pragma config PBADEN = OFF
// #pragma config CCP2MX = ON
#pragma config STVREN = ON
#pragma config LVP = OFF
// #pragma config ICPRT = OFF // Dedicated In-Circuit Debug/Programming
#pragma config XINST = OFF // Extended Instruction Set
#pragma config CP0 = OFF
#pragma config CP1 = OFF
// #pragma config CP2 = OFF
// #pragma config CP3 = OFF
#pragma config CPB = OFF
// #pragma config CPD = OFF
#pragma config WRT0 = OFF
#pragma config WRT1 = OFF
// #pragma config WRT2 = OFF
// #pragma config WRT3 = OFF
#pragma config WRTB = OFF // Boot Block Write Protection
#pragma config WRTC = OFF
// #pragma config WRTD = OFF
#pragma config EBTR0 = OFF
#pragma config EBTR1 = OFF
// #pragma config EBTR2 = OFF
// #pragma config EBTR3 = OFF
#pragma config EBTRB = OFF
#endif
//******************************DECLARATION OF GLOBAL VARIABLES**************************************************************
char data;
volatile unsigned char cUART_data_flg, cUART_char;
//******************************Declaration of Function Prototype************************************************************
char ReadUSART( void );
void init_uart(void);
void UART_putc(unsigned char c);
void InterruptHandlerLow ();
void WriteUSART( char data );
//***************************************************************************************************************************
// LED Setings:
#define setpin() TRISB = 0; // Set all pins to output
#define LED1 LATBbits.LATB1 // RB1
#define LED1_on()LED1 = 1; // Set pin to High
#define LED1_off()LED1 = 0; // Set pin to Low
void main(void)
{
setpin(); // Init LED
init_uart(); // Init UART module
while(1) // Create Loop
{
while(!cUART_data_flg); // Wait for data
cUART_data_flg = 0;
//data = ReadUSART(); // Read data
PORTB = cUART_char; // The receive data is send to PORTB
if(cUART_char=='1') { // If the received data is equal to the 'A'
LED1_on(); // LED blinking
Delay10KTCYx(250); // Dealay 250K cycles
LED1_off();
}
}
}
//***************************************************************************************************************************
#pragma code InterruptVectorLow = 0x18
void IntLow (void)
{
_asm
goto InterruptHandlerLow // jump to interrupt routine
_endasm
}
//**************************************************************************************************************************
// Low priority interrupt routine
#pragma code
#pragma interruptlow InterruptHandlerLow
void InterruptHandlerLow()
{
if (PIR1bits.RCIF==1) // Is interrupt occured by EUSART receive?,
// Then RCREG is full we have new data (cleared when RCREG is read)
{
if(RCSTA&0x06) // More efficient way than following commented method to check for reception error
//if(RCSTAbits.FERR==1 || RCSTAbits.OERR==1 )
{
RCSTAbits.CREN=0; // Overrun error (can be cleared by clearing bit CREN)
cUART_char=RCREG; // Clear Framing error
RCSTAbits.CREN=1;
}
else
{
cUART_char = RCREG; // Read new data into variable
cUART_data_flg = 1; // New data received. so enable flg
}
}
}
//***************************************************************************************************************************
void init_uart(void) // Init UART module for 9600bps boud, start bit 1, stopbit 1, parity NONE
{
cUART_data_flg=0; // Init data receive flag to zero (no data)
TRISCbits.TRISC7=1; // Make UART RX pin input
TRISCbits.TRISC6=0; // Make UART TX pin output
SPBRGH = 0x02; // 9600bps 20MHz Osc
SPBRG = 0x08;
RCSTAbits.CREN=1; // 1 = Enables receiver
RCSTAbits.SPEN=1; // 1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins)
BAUDCONbits.BRG16=1; // 1 = 16-bit Baud Rate Generator – SPBRGH and SPBRG
TXSTAbits.SYNC=0; // 0 = Asynchronous mode
TXSTAbits.BRGH=1; // 1 = High speed
TXSTAbits.TXEN=1; // 1 = Transmit enabled
RCONbits.IPEN = 1; // Enable Interrupt priority levels
IPR1bits.RCIP=0; // EUSART Receive Interrupt Priority 0 = Low priority
PIE1bits.RCIE=1; // 1 = Enables the EUSART receive interrupt
INTCONbits.GIEL = 1; // Enable interrupts
INTCONbits.GIEH = 1;
}
//****************************************************************************************************************************
void UART_putc(unsigned char c)
{
TXSTAbits.TXEN=0; // Disable transmission
TXREG=data; // Load txreg with data
TXSTAbits.TXEN=1; // Enable transmission
while(TXSTAbits.TRMT==0) // Wait here till transmit complete
{
Nop();
}
}
).
