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May 10, 2017 at 3:15 pm #13755

Topic: Problems with SPI

in forum PIC Microcontroller

Yash
Participant

Hey guys,

I am working with PIC18F4620 micro in MPLAB with XC8 compiler below is the code I have written to initialize SPI. In the code i am trying to generate clock pluses by continuously sending 0xAA to the SPI output and I am simulating this code in PIC18 simulator, but I am not getting any signal on either of the pins (clk or the DO) and similarly I am also not getting any signal on the IC too. In simulation it is stuck at SSPSTAT –> BF waiting for it to go high and even if I set the flag high in simulation manually it still won’t generate any clock signal. There must be some silly mistake that I might have made please have a look.

Code

#include <xc.h>

#include <stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <math.h>

#include <pic18f4620.h>

// PIC18F4620 Configuration Bit Settings

// CONFIG1H

#pragma config OSC = HSPLL // Oscillator Selection bits (HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1))

#pragma config FCMEN = OFF // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)

#pragma config IESO = OFF // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)

// CONFIG2L

#pragma config PWRT = ON // Power-up Timer Enable bit (PWRT enabled)

#pragma config BOREN = ON // Brown-out Reset Enable bits (Brown-out Reset enabled and controlled by software (SBOREN is enabled))

#pragma config BORV = 3 // Brown Out Reset Voltage bits (Minimum setting)

// CONFIG2H

#pragma config WDT = OFF // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit))

#pragma config WDTPS = 32768 // Watchdog Timer Postscale Select bits (1:32768)

// CONFIG3H

#pragma config CCP2MX = PORTC // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1)

#pragma config PBADEN = OFF // PORTB A/D Enable bit (PORTB<4:0> pins are configured as digital I/O on Reset)

#pragma config LPT1OSC = OFF // Low-Power Timer1 Oscillator Enable bit (Timer1 configured for higher power operation)

#pragma config MCLRE = ON // MCLR Pin Enable bit (MCLR pin enabled; RE3 input pin disabled)

// CONFIG4L

#pragma config STVREN = OFF // Stack Full/Underflow Reset Enable bit (Stack full/underflow will not cause Reset)

#pragma config LVP = OFF // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled)

#pragma config XINST = OFF // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))

// CONFIG5L

#pragma config CP0 = OFF // Code Protection bit (Block 0 (000800-003FFFh) not code-protected)

#pragma config CP1 = OFF // Code Protection bit (Block 1 (004000-007FFFh) not code-protected)

#pragma config CP2 = OFF // Code Protection bit (Block 2 (008000-00BFFFh) not code-protected)

#pragma config CP3 = OFF // Code Protection bit (Block 3 (00C000-00FFFFh) not code-protected)

// CONFIG5H

#pragma config CPB = OFF // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected)

#pragma config CPD = OFF // Data EEPROM Code Protection bit (Data EEPROM not code-protected)

// CONFIG6L

#pragma config WRT0 = OFF // Write Protection bit (Block 0 (000800-003FFFh) not write-protected)

#pragma config WRT1 = OFF // Write Protection bit (Block 1 (004000-007FFFh) not write-protected)

#pragma config WRT2 = OFF // Write Protection bit (Block 2 (008000-00BFFFh) not write-protected)

#pragma config WRT3 = OFF // Write Protection bit (Block 3 (00C000-00FFFFh) not write-protected)

// CONFIG6H

#pragma config WRTC = OFF // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected)

#pragma config WRTB = OFF // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)

#pragma config WRTD = OFF // Data EEPROM Write Protection bit (Data EEPROM not write-protected)

// CONFIG7L

#pragma config EBTR0 = OFF // Table Read Protection bit (Block 0 (000800-003FFFh) not protected from table reads executed in other blocks)

#pragma config EBTR1 = OFF // Table Read Protection bit (Block 1 (004000-007FFFh) not protected from table reads executed in other blocks)

#pragma config EBTR2 = OFF // Table Read Protection bit (Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks)

#pragma config EBTR3 = OFF // Table Read Protection bit (Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks)

// CONFIG7H

#pragma config EBTRB = OFF // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)

#define rs PORTDbits.RD6 //LATBbits.LB6

#define en PORTDbits.RD7 //LATBbits.LB7

#define _XTAL_FREQ 40000000

#define le PORTDbits.RD4 //bus bar control

#define watch 0b00000001

#define drain_valve 0b10000000

#define cal_led 0b01000000

#define level_sw PORTEbits.RE2

#define CS_PIN PORTCbits.RC2 //3 // Chip Select

#define TRIS_CS_PIN TRISCbits.TRISC2

#define DIN_PIN PORTCbits.RC4 // Data in

#define TRIS_DIN_PIN TRISCbits.TRISC4

#define DOUT_PIN PORTCbits.RC5 //6 // Data out

#define TRIS_DOUT_PIN TRISCbits.TRISC5

#define SCK_PIN PORTCbits.RC3 //5 // Clock

#define TRIS_SCK_PIN TRISCbits.TRISC3

void config_spi(void);

unsigned char write_spi(unsigned char mybyte);

unsigned char read_spi(void);

void main(){

TRISB =0x00; // lcd 0-7

TRISD =0x00; // D6, D7

TRISC = 0b10010011;

TRISE =0b101;

PORTEbits.RE1 = 0;

PORTB =0x00;

PORTD =0x00;

CS_PIN = 1; // Chip Select

ADCON0 = 0x00;

ADCON1 = 0b00001111; // all pins digital

unsigned char data=’a’;

config_spi();

while(1) write_spi(0xAA);

}

void config_spi(void){

TRIS_CS_PIN = 0;

TRIS_DIN_PIN = 1;

TRIS_DOUT_PIN = 0;

TRIS_SCK_PIN = 0;

SSPSTAT =0b10000000;

//SSPCON1 =0x22;

SSPCON1 = 0b00100010;

SSPADD =0x00;

CS_PIN = 0; // Chip Select

}

unsigned char write_spi(unsigned char mybyte){

SSPCON1bits.WCOL =0;

PIR1bits.SSPIF =0;

SSPBUF = mybyte;

//while(!SSPSTATbits.BF);

while(!PIR1bits.SSPIF);

return SSPBUF;

}

unsigned char read_spi(void){

while(!SSPSTATbits.BF);

return SSPBUF;

}

April 10, 2017 at 5:54 pm #13657

Topic: programming an audio signal using pic18f and Interrupt service Routine

in forum PIC Microcontroller

yamabonadine
Participant

Hi,

I have in my pocession a microphone, an amplifier and a pic18f452. I have already connected the microphone to the amplifier. I did it on a turntable. I will connect the output of my microphone on the deck with an annalog port on the picdem Board and ground with ground on the picdem board. The channelA0 of the picdem board is reserved for the potentiometer so I have to use another port different from port A to connect the output of my Microphone, for exemple PORTC.
concerning programming I have to write a program that allows me to digitize this analog signal from the microphone and send it through the uart of my picdem board to a module blutooth HC05. the Picdem Board have an integrated ADC (10bit).

this is what i already do.can you suggest me anything? MY CODE

#pragma config OSC=HS,WDT=OFF,LVP=OFF // HS Oszillator, Watchdog Timer disabled, Low Voltage Programming

#include “p18f452.h”

#include “lcd.h”

extern void lcd_printf (const char* message);

extern void lcd_gotoxy (char row,char column);

extern void lcd_clear (void);

extern void lcd_init (void);

extern void lcd_byte (char num);

extern void lcd_int (int num);

extern void lcd_putc (char num);

void high_prior_InterruptHandler (void);

void low_prior_InterruptHandler (void);

unsigned int x=0, y=0;

unsigned char signal_in[];

unsigned char signal_out[];

unsigned char empfangspuffer,sendepuffer;

#pragma code high_prior_InterruptVector = 0x08

void high_prior_InterruptVector(void)

{

_asm

goto high_prior_InterruptHandler

_endasm

}

#pragma code low_prior_InterruptVector = 0x18

void low_prior_InterruptVector(void)

{

_asm

goto low_prior_InterruptHandler

_endasm

}

void init (void)

{

lcd_init();

lcd_clear();

/*UART serielle Schnittstelle initialisieren*/

RCSTAbits.SPEN = 1; // Serial Port Enabled for TX & RX

RCSTAbits.CREN = 0; // Continuous Receive Enabled

TXSTAbits.BRGH = 1; // High Baud Rate Selected

SPBRG = 25; // Naud Rate = FOSC / (16(X+1)) // 4MHZ Asynch & HSpeed

TXSTAbits.SYNC = 0;

/*ISR ,Interrupt Serielle Schnittstelle initialisieren*/

PIE1bits.RCIE = 1; //Enable USART Interrupt

PIR1bits.RCIF = 0; //Clear USART RX Interrupt Flag

IPR1bits.RCIP = 1; //High Priority Enable

TRISCbits.TRISC6 = 1; // 0b10111111;

//AD-Interrupts

PIR1bits.ADIF = 0; // Clear ADC Interrupt Flag

IPR1bits.ADIP = 0; //SET to Low Priority

PIE1bits.ADIE = 1; // Enable ADC Interrupt

// Allgemeine Interrupts

RCONbits.IPEN = 1;

INTCONbits.GIE =1;

INTCONbits.PEIE =1;

//AD Einstellungen

TRISAbits.RA0 = 1; //Port RA0 Poti auf Eingang setzen

TRISEbits.RE0 = 1; //configure RE0 as input pin for Microphone

ADCON1=0x8B; // Make RA0/AN0 and RE0 pin as analog pin

ADCON0=0xA9; //Fosc/32, Channel 5

ADCON0bits.ADON = 1; // Enable ADC

}

/* UART Receive*/

#pragma code

#pragma interrupt high_prior_InterruptHandler

void high_prior_InterruptHandler(void)

{

//code

}

/*sendung mit uart TX*/

#pragma code

#pragma interrupt low_prior_InterruptHandler

void low_prior_InterruptHandler(void)

{

//code

}

/*AD Wandlung*/

#pragma code

#pragma interrupt low_prior_InterruptHandler

void low_prior_InterruptHandler(void)

{

if(PIR1bits.ADIF == 1) //A/D-Wandlung starten

{

x = ADRESH; //A/D-Ergebnis Bit 2 bis 10

y = ADRESL;

PIR1bits.ADIF = 0;

ADCON0bits.GO_DONE = 1; // ADC neu starten

}

void main()

{

//code

}

i want your help for Programming please.

Regards

April 10, 2017 at 5:49 pm #13656

Topic: programming an audio signal using pic18f and Interrupt service Routine

in forum PIC Microcontroller

yamabonadine
Participant

Hi,
I have in my pocession a microphone, an amplifier and a pic18f452. I have already connected the microphone to the amplifier. I did it on a turntable. I will connect the output of my microphone on the deck with an annalog port on the picdem Board and ground with ground on the picdem board. The channelA0 of the picdem board is reserved for the potentiometer so I have to use another port different from port A to connect the output of my Microphone, for exemple PORTC.
concerning programming I have to write a program that allows me to digitize this analog signal from the microphone and send it through the uart of my picdem board to a module blutooth HC05. the Picdem Board have an integrated ADC (10bit).
this is what i already do.can you suggest me anything? MY CODE

#pragma config OSC=HS,WDT=OFF,LVP=OFF // HS Oszillator, Watchdog Timer disabled, Low Voltage Programming
#include “p18f452.h”
#include “lcd.h”
extern void lcd_printf (const char* message);
extern void lcd_gotoxy (char row,char column);
extern void lcd_clear (void);
extern void lcd_init (void);
extern void lcd_byte (char num);
extern void lcd_int (int num);
extern void lcd_putc (char num);
 
void high_prior_InterruptHandler (void);
void low_prior_InterruptHandler (void);
 
unsigned int x=0, y=0;
unsigned char signal_in[];
unsigned char signal_out[];
unsigned char empfangspuffer,sendepuffer;
 
#pragma code high_prior_InterruptVector = 0x08
 
void high_prior_InterruptVector(void)
{
 _asm
 goto high_prior_InterruptHandler
 _endasm
}
 
#pragma code low_prior_InterruptVector = 0x18
 
void low_prior_InterruptVector(void)
{
 _asm
 goto low_prior_InterruptHandler
 _endasm
}
 
 
 
void init (void)
{
 lcd_init();
 lcd_clear();
 
/*UART serielle Schnittstelle initialisieren*/
 RCSTAbits.SPEN = 1; // Serial Port Enabled for TX & RX
 RCSTAbits.CREN = 0; // Continuous Receive Enabled
 TXSTAbits.BRGH = 1; // High Baud Rate Selected 
 SPBRG = 25; // Naud Rate = FOSC / (16(X+1)) // 4MHZ Asynch & HSpeed
 TXSTAbits.SYNC = 0;
/*ISR ,Interrupt Serielle Schnittstelle initialisieren*/
 PIE1bits.RCIE = 1; //Enable USART Interrupt
 PIR1bits.RCIF = 0; //Clear USART RX Interrupt Flag
 IPR1bits.RCIP = 1; //High Priority Enable
 TRISCbits.TRISC6 = 1; // 0b10111111;
//AD-Interrupts 
 PIR1bits.ADIF = 0; // Clear ADC Interrupt Flag
 IPR1bits.ADIP = 0; //SET to Low Priority
 PIE1bits.ADIE = 1; // Enable ADC Interrupt
// Allgemeine Interrupts
 RCONbits.IPEN = 1;
 INTCONbits.GIE =1;
 INTCONbits.PEIE =1;
//AD Einstellungen
 TRISAbits.RA0 = 1; //Port RA0 Poti auf Eingang setzen
 TRISEbits.RE0 = 1; //configure RE0 as input pin for Microphone
 ADCON1=0x8B; // Make RA0/AN0 and RE0 pin as analog pin 
 ADCON0=0xA9; //Fosc/32, Channel 5
 ADCON0bits.ADON = 1; // Enable ADC
}
 
/* UART Receive*/
#pragma code
#pragma interrupt high_prior_InterruptHandler
 
 
void high_prior_InterruptHandler(void)
{
 
 //code
 
}
 
/*sendung mit uart TX*/
#pragma code
#pragma interrupt low_prior_InterruptHandler
 
void low_prior_InterruptHandler(void)
{
 //code
}
 
/*AD Wandlung*/
#pragma code
#pragma interrupt low_prior_InterruptHandler
 
void low_prior_InterruptHandler(void)
{
 if(PIR1bits.ADIF == 1) //A/D-Wandlung starten
 {
 x = ADRESH; //A/D-Ergebnis Bit 2 bis 10
 y = ADRESL;
 PIR1bits.ADIF = 0;
 ADCON0bits.GO_DONE = 1; // ADC neu starten
 }
 
 
void main()
{
 
}
i want your help for Programming please.
Regards

February 2, 2017 at 7:08 pm #13461

Topic: Interfacing 2 HC-SR04 to PIC Microcontroller

in forum PIC Microcontroller

charmi pabari
Participant

How can I interface two HC-SR04 ultrasonic distance sensor with PIC 16F877A using a single timer (timer 1) ?

February 2, 2017 at 4:07 pm #13455

Topic: Using Capture and Compare mode together – PIC 12F1840

in forum PIC Microcontroller
GITANJALI
Participant
Hello,

I am working on PIC 12F1840 and MPLABX IDE 3.35 . I have written a code for reading PWM pulse width at one pin and writing that value to another PWM pin. But, at the time of simulation in logic analyzer output PWM pulse is not continuous. Is it a correct way to use capture mode and compare mode in one code ? Please check following code and guide me.
```
/*
* File: general.c
* Author: Murumkar
*
* Created on 25 January, 2017, 9:27 AM

*
*
* read input (freq 400Hz) RA2 pulse width and write to RA5 (PWM with freq 18Kz)
*
*
*/

#include <stdio.h>
#include <stdlib.h>
#include <xc.h>
#pragma config FOSC =INTOSC, PLLEN =OFF, WDTE =OFF, MCLRE =ON,
#pragma config CLKOUTEN =OFF, IESO =OFF, FCMEN =OFF,CP =OFF, CPD =OFF,BOREN=OFF
#pragma config WRT=OFF,STVREN=ON,BORV=LO,LVP=OFF

unsigned char counter=0;//Overflow counter
int count = 0;
unsigned char timer1_value1 @ 0x2020;
unsigned char timer1_value2 @ 0x2040;
unsigned int timer1_value @ 0x2060;
unsigned int Pulse @ 0x2080;
unsigned int PulseWidth @ 0x20A0;

delay()
{
 int i;
 for(i=0;i<30;i++)
 {
 ;
 }
}

void pwm_start()
{
 TRISAbits.TRISA2 = 1;
 APFCONbits.CCP1SEL = 0;
 CCP1CONbits.CCP1M = 0x05; // capture mode with each rising edge
 TRISAbits.TRISA2 = 0;

 TRISAbits.TRISA2 = 1; // RA2 as input
 ANSELAbits.ANSA2 = 0; // RA2 as Digital
}

void init_interrupt()
{
 INTCONbits.GIE = 1; // enable global interrupt
 INTCONbits.PEIE = 1; // enable peripheral interrupt
 PIE1bits.TMR1IE = 1; // enable timer 1
 PIE1bits.CCP1IE = 1; // enable capture mode interrupt
}

void pwm_again_start()
{
 TRISAbits.TRISA5 = 1; // RA5
 APFCONbits.CCP1SEL = 1; // CCP1 function on RA5
 CCP1CONbits.CCP1M = 0x0C; // PWM mode: P1A active-high; P1B active-high
 CCP1CONbits.P1M = 0x00; // Single output; P1A modulated; P1B assigned as port pins
 PR2 = 0xDD; //
 CCPR1L = 0x00; // UPDATE PWM TON=0
 CCP1CONbits.DC1B = 0x00; // the two LSbs of the PWM duty CYCLE
 PIR1bits.TMR2IF = 0; // TIMER2 FLAG CLEAR
 T2CONbits.T2CKPS = 0x00; // PRESCALER 1
 T2CONbits.TMR2ON = 1; // TIMER 1
 TRISAbits.TRISA5 = 0; //
}

void SetPWMDutyCyle(unsigned int duty_cycle_value)
{
 CCP1CONbits.DC1B = duty_cycle_value & 0x03; // two LSbs of the PWM duty cycle.
 CCPR1L = (duty_cycle_value >> 2); // MSB VALUES
 while(PIR1bits.TMR2IF==1)
 {
 PIR1bits.TMR2IF =0;
 }
 T2CONbits.TMR2ON = 1; // TIMER 1*/
 delay();
}

void interrupt ISR()
{
 if(PIE1bits.CCP1IE && PIR1bits.CCP1IF)
 {
 count++;
 if(count==1)
 {
 T1CONbits.TMR1ON = 1; // start timer 1
 PORTAbits.RA1 = ~PORTAbits.RA1;
 counter = 0;
 PIR1bits.CCP1IF = 0;
 CCP1CONbits.CCP1M = 0x04; // capture mode with each falling edge
 timer1_value1 = TMR1L;
 timer1_value2 = TMR1H;
 timer1_value = timer1_value1 + (((int)TMR1H) << 8);
 }
 else if(count==2)
 {
 count = 0;
 PORTAbits.RA1 = ~PORTAbits.RA1;
 INTCONbits.GIE = 0; // disable global interrupt
 INTCONbits.PEIE = 0; // disable peripheral interrupt
 PIE1bits.TMR1IE = 0; // disable timer 1
 PIE1bits.CCP1IE = 0; // disable capture mode interrupt
 counter = 0;
 PIR1bits.CCP1IF = 0;
 CCP1CONbits.CCP1M = 0x05; // capture mode with each rising edge
 timer1_value1 = TMR1L;
 timer1_value2 = TMR1H;
 Pulse = timer1_value1 + (((int)TMR1H) << 8);
 PulseWidth = Pulse - timer1_value;
 pwm_again_start();
 SetPWMDutyCyle(PulseWidth);
 pwm_start();
 init_interrupt();
 }
 }
}

void micro_init()
{
 OSCCONbits.SPLLEN = 0; // PLL DISABLE
 OSCCONbits.IRCF = 0x0F; // 16 MHZ INTERNAL FREQ
 OSCCONbits.SCS = 0x02; // INTERNAL OSCILLATR BLOCK
}

void main()
{
 micro_init();
 pwm_start();

 TRISAbits.TRISA1 = 0; // RA1 as output
 ANSELAbits.ANSA1 = 0; // RA1 as digital

 TRISAbits.TRISA2 = 1; // RA2 as input
 ANSELAbits.ANSA2 = 0; // RA2 as Digital

 TRISAbits.TRISA5 = 0; // RA5 as output

 init_interrupt();
 while (1)
 {
 ;
 }
}
```
thanking you ,

Gitanjali
February 1, 2016 at 1:16 pm #12100

Topic: PIC Microcontroller Non-Blocking Delay Implementation

in forum PIC Microcontroller
emufambirwi
Participant
I am doing a project which requires that I turn on and off two LED’s independently from a computer using serial port communication. I send a character like ‘A’ via the serial port and turn on one LED for say 1 minute and send another character like ‘B’ and turn on another LED for 2 minutes. My problem is that when using Timer0 of pic 18F87k22, I can’t implement the 1 minute and 2 minute delays independently. When I turn on the one LED the other one doesn’t respond and vice versa. I am simulating using Proteus and my code is is in MikroC as shown below:
```
char uart_rd;
char cnt;

void interrupt () 
{
 if (TMR0IF_bit) 
 {
 cnt++;                 // increment counters
 TMR0IF_bit = 0;        // clear TMR0IF

 TMR0L = 0xDC;             // set TMR0 for aproximetly 1 sec
 TMR0H = 0x0B;
 }
}

void one_min_delay () 
{
 TRISB  = 0;              // PORTB is output
 TMR0H = 0x0B;
 TMR0L = 0xDC;               // Timer0 initial value

 T0CON = 0x84;            // Set TMR0 to 8bit mode and prescaler to 256
 GIE_bit = 1;             // Enable global interrupt
 TMR0IE_bit = 1;          // Enable Timer0 interrupt

 cnt = 0;                 // Initialize cnt

 do 
 {
 if (cnt >= 60) 
 {
 LATB = 0x00;      // turnoff PORTB LEDs
 cnt = 0;             // Reset cnt
 }
 }while(1);
}

void two_min_delay () 
{
 TRISB  = 0;              // PORTB is output
 TMR0H = 0x0B;
 TMR0L = 0xDC;               // Timer0 initial value
 T0CON = 0x84;            // Set TMR0 to 8bit mode and prescaler to 256
 GIE_bit = 1;             // Enable global interrupt
 TMR0IE_bit = 1;          // Enable Timer0 interrupt

 cnt = 0;                 // Initialize cnt

 do 
 {
 if (cnt >= 120) 
 {
 LATB = 0x00;      // turnoff PORTB LEDs
 cnt = 0;             // Reset cnt
 }
 }while(1);
}

void main() 
{
 UART1_Init(9600);               // Initialize UART module at 9600 bps
 Delay_ms(100);                  // Wait for UART module to stabilize
 TRISB = 0x00;

 while (1) 
 {
 if (UART1_Data_Ready()) 
 {     // If data is received,
 uart_rd = UART1_Read();
 }

 if (uart_rd=='A')   
 {
 LATB = 0x01;
 one_min_delay();
 }
 else if (uart_rd == 'B')   
 {
 PORTB = 0x02;
 two_min_delay ();
 }
 uart_rd ='\0';
 }
}
```
March 24, 2015 at 1:02 pm #11112

In reply to: RPM sensing using hall effect sensor

Ligo George
Keymaster

Using Interrupt with PIC Microcontroller – MikroC

Please read the datasheet of PIC 16F877A microcontroller… there you can find the procedure to use timer / counter module.

March 23, 2015 at 10:59 pm #11111

In reply to: RPM sensing using hall effect sensor

Yash
Participant

I am using PIC16F877A with 8MHz external oscillator. And coding in MicroC

Idea is to measure the pules produce by the sensor for 1 sec and then multiply the value with 60 hence the RPM which I will display on LCD.

Please tell me if my method is right and how to implement it. As I want to show rpm on lcd so I would like it be slow enough so that rpm readings are stable.

I have no experience in timers if you can give me a basic code to get started with, then I can play with it and find my way to solution ?

Thank You.

January 18, 2015 at 9:30 am #10509

Topic: Timer0 of PIC 16F887

in forum PIC Microcontroller
chirag patel
Participant
hi, i m trying to interrupt timer on specific time but its doing randomly please help me out.
```
#include <htc.h>
unsigned  char vary,count=10;
#define _XTAL_FREQ 4000000

void main()
{
 TRISD=0b00000000;
 //PORTD=0b00000000;

 GIE=1;
 T0IE=1;
 TMR0=0;
 PSA=0;
 T0CS=0;
 PS0=1;
 PS1=1;
 PS2=0;
 T0SE=1;

 while (1)
 {
 PORTD=0b00000000;
 }
}
static void interrupt isr()
{
 if (T0IF == 1)
 {
 GIE=0;
 T0IF=0;
 vary++;
 if (vary=1)
 {
 PORTD= 0b11111111;
 }
 vary=0;
 GIE=1;
 T0IE=1;
 }
}
```
January 8, 2015 at 1:39 pm #10434

Topic: Interfacing HC-SR04 Ultrasonic Sensor with PIC 16F676 using Hi-Tech C

in forum PIC Microcontroller
sahu
Participant
With reference to the article Interfacing HC-SR04 Ultrasonic Distance Sensor with PIC Microcontroller, I am trying to change the microcontroller to PIC 16F676.
```
#define _XTAL_FREQ 8000000

#define RS RC5
#define EN RC4
#define D4 RC0
#define D5 RC1
#define D6 RC2
#define D7 RC3

//#include <xc.h>
#include <htc.h>

#include "lcd.h";
#include <pic16f676.h>

// BEGIN CONFIG
#pragma config FOSC = HS // Oscillator Selection bits (HS oscillator)
#pragma config WDTE = OFF // Watchdog Timer Enable bit (WDT enabled)
#pragma config PWRTE = OFF // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = ON // Brown-out Reset Enable bit (BOR enabled)
//#pragma config LVP = OFF // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)
#pragma config CPD = OFF // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off)
//#pragma config WRT = OFF // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control)
#pragma config CP = OFF // Flash Program Memory Code Protection bit (Code protection off)
//END CONFIG

void delayMs(int x);

void main()
{
 int a;

 TRISA = 0b00010001; //RA0 as Input PIN (ECHO)
 TRISC = 0x00; // LCD Pins as Output

 Lcd_Init();

 Lcd_Set_Cursor(1,1);
 Lcd_Write_String("Developed By");
 Lcd_Set_Cursor(2,1);
 Lcd_Write_String("electroSome");

 delayMs(3000);
 Lcd_Clear();

 T1CON = 0x10; //Initialize Timer Module

 while(1)
 {
 TMR1H = 0; //Sets the Initial Value of Timer
 TMR1L = 0; //Sets the Initial Value of Timer

 RA0 = 1; //TRIGGER HIGH
 __delay_us(10); //10uS Delay
 RA0 = 0; //TRIGGER LOW

 while(!RA1); //Waiting for Echo
 TMR1ON = 1; //Timer Starts
 while(RA1); //Waiting for Echo goes LOW
 TMR1ON = 0; //Timer Stops

 a = (TMR1L | (TMR1H<<8)); //Reads Timer Value
 a = a/58.82; //Converts Time to Distance
 a = a + 1; //Distance Calibration
 if(a>=2 && a<=400) //Check whether the result is valid or not
 {
 Lcd_Clear();
 Lcd_Set_Cursor(1,1);
 Lcd_Write_String("Distance = ");

 Lcd_Set_Cursor(1,14);
 Lcd_Write_Char(a%10 + 48);

 a = a/10;
 Lcd_Set_Cursor(1,13);
 Lcd_Write_Char(a%10 + 48);

 a = a/10;
 Lcd_Set_Cursor(1,12);
 Lcd_Write_Char(a%10 + 48);

 Lcd_Set_Cursor(1,15);
 Lcd_Write_String("cm");
 }
 else
 {
 Lcd_Clear();
 Lcd_Set_Cursor(2,1);
 Lcd_Write_String("Out of Range");
 }
 delayMs(400);
 }
}
/************************************************************/

void delayMs(int x)
{
 int i;
 for (x ;x>0;x--)
 {
 for (i=0;i<=110;i++);
 }
}
```
I am using Hi-Tech C compiler and getting following errors.

Error [1347] ; 0. can’t find 0x21 words (0x21 withtotal) for psect “text142” in segment “CODE” (largest unused contiguous range 0x1E)
Error [1347] ; 0. can’t find 0x12 words (0x12 withtotal) for psect “text140” in segment “CODE” (largest unused contiguous range 0x7)
Error [1347] ; 0. can’t find 0xF words (0xf withtotal) for psect “text144” in segment “CODE” (largest unused contiguous range 0x7)
December 9, 2014 at 1:00 pm #10165

Topic: LCD and UART PIC Microcontroller

in forum PIC Microcontroller
Ivan
Participant
I’m trying send data to the PIC using the Terminal Window on Proteus, but something is wrong and I don’t understand why. I attached the Proteus project and *.HEX.

The PIC is 16F628a.
```
#define _XTAL_FREQ 8000000

#define RS RB0
#define EN RB3
#define D4 RB4
#define D5 RB5
#define D6 RB6
#define D7 RB7

#include <xc.h>
#include "lcd.h"
#include "uart.h"

#pragma config FOSC = INTOSCCLK // Oscillator Selection bits (INTOSC oscillator: CLKOUT function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF      // RA5/MCLR/VPP Pin Function Select bit (RA5/MCLR/VPP pin function is digital input, MCLR internally tied to VDD)
#pragma config BOREN = ON       // Brown-out Detect Enable bit (BOD enabled)
#pragma config LVP = OFF        // Low-Voltage Programming Enable bit (RB4/PGM pin has digital I/O function, HV on MCLR must be used for programming)
#pragma config CPD = OFF        // Data EE Memory Code Protection bit (Data memory code protection off)
#pragma config CP = OFF         // Flash Program Memory Code Protection bit (Code protection off)

void main()
{
 TRISB = 0b000000110;
 TRISA0 = 0;

 Lcd_Init();
 Lcd_Clear();
 Lcd_Set_Cursor(1,1);
 Lcd_Write_String("WAITING...");

 UART_Init(9600);
 UART_Write_Text("Terminal is running!");

 while(1)
 {
 if(UART_Data_Ready())
 {
 Lcd_Clear();
 RA0 = 1;
 Lcd_Write_String(UART_Read_Text);
 __delay_ms(1000);
 }
 }
}
```
The UART.h and LCD.h from https://electrosome.com/lcd-pic-mplab-xc8/ and https://electrosome.com/uart-pic-microcontroller-mplab-xc8/

Somebody know why the code is not working?
December 9, 2014 at 12:42 pm #10164

In reply to: PIC C Compiler and HC-SR04 Ultrasonic Sensor
Ligo George
Keymaster
Hello, It seems like you converted our program in the article Interfacing HC-SR04 with PIC Microcontroller to CCS C.

In that tutorial I used prescaler : 2, so you should use :
```
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_2);
```
and you should change a-4 to a in printf().

Please check the above program after making these changes and let me know whether it works or not. If it works, I can include it too in that article such that it will help others too.
December 8, 2014 at 7:39 pm #10154

Topic: PIC C Compiler and HC-SR04 Ultrasonic Sensor

in forum PIC Microcontroller
enhee enheelee
Participant
What is wrong. The below code. Please help me.
```
#include "C:\Users\enhee\Documents\lcd16f873a.h"
#define use_portb_lcd TRUE
#include <LCD.C>
#byte timer1=0x10
#bit  trigger=0x07.2
#bit  echo=0x07.1
#bit on_off=0x10.0

unsigned char zai=12;

void main()
{
 float a;
 set_tris_c(0x02);
 timer1=0x10;

 setup_adc_ports(NO_ANALOGS);
 setup_adc(ADC_OFF);

 setup_spi(SPI_SS_DISABLED);

 setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
 setup_timer_1(T1_DISABLED);
 setup_timer_2(T2_DISABLED,0,1);

 setup_comparator(NC_NC_NC_NC);
 setup_vref(FALSE);

 lcd_init();
 lcd_gotoxy(1,1);
 printf(lcd_putc,"zai medregch");

 for(;;)
 {
 set_timer1(0x0000);
 trigger=1;
 delay_us(10);
 trigger=0;

 while(!echo);      //Waiting for Echo
 on_off = 1;       //Timer Starts
 while(echo);       //Waiting for Echo goes LOW
 on_off = 0;       //Timer Stops

 a=get_timer1();
 a = a/58.82;
 a = a + 1;

 if(a>=2 && a<=400)   //Check whether the result is valid or not
 {
 lcd_gotoxy(1,2);
 printf(lcd_putc,"zai=%f cm",a-4);
 }
 else
 {
 lcd_gotoxy(1,2);
 printf(lcd_putc,"heterhii hol bna");
 }
 delay_ms(200);
 }
}
```
October 3, 2014 at 1:18 pm #9378

In reply to: watchdog timer in pic18f

Ligo George
Keymaster

PIC may reset due to different problems..
Unexpected reset might not be due to Watchdog timer..
Use a good power supply..

October 3, 2014 at 1:11 pm #9359

In reply to: timer in pic18f
Ligo George
Keymaster
You may solve it by incrementing a variable as above…. but the best solution is to use PIC’s internal timer module..
eg :
```
//Start Timer
for(a=read_timer;a< a_value;)
{
 //Do Something
}
//Stop Timer
```
You can use Timer0 module… Read the Timer0 section in the datasheet.
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