Good day to all,
Please i need your support.I am Controlling Led brightness with PWM Signal and at the same time Displaying the duty cycle(represented in %) on an Lcd Display.The Problem i am having is that the percentage of the duty cycle shown on the oscilloscope is different from the value shown on my Lcd Display.For example when the oscilloscope showed 50% duty cycle the value shown on the LCD was 38%.I would be glad if somebody could help me have a look at my code may be there is something i am not doing correctly.Below are my lines of code.Thank you for the usual Support.
Best regards.
Please i need your support.I am Controlling Led brightness with PWM Signal and at the same time Displaying the duty cycle(represented in %) on an Lcd Display.The Problem i am having is that the percentage of the duty cycle shown on the oscilloscope is different from the value shown on my Lcd Display.For example when the oscilloscope showed 50% duty cycle the value shown on the LCD was 38%.I would be glad if somebody could help me have a look at my code may be there is something i am not doing correctly.Below are my lines of code.Thank you for the usual Support.
Best regards.
Rich (BB code):
# define F_CPU 1000000UL
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/delay.h>
#include "NewHeaven_LCD.h"
#include "USI_TWI_Master.h"
#define SLAVE_ADDR 0x50
#define MESSAGEBUF_SIZE 20
#define TWI_GEN_CALL 0x00 // The General Call address is 0
// Sample TWI transmission commands
//#define TWI_CMD_MASTER_WRITE 0x28
//#define TWI_CMD_MASTER_READ 0x29
// Sample TWI transmission states, used in the main application.
#define SEND_DATA 0x01
#define REQUEST_DATA 0x02
#define READ_DATA_FROM_BUFFER 0x03
#define RTC_ADDRRESS 0x34 //0x68
#define RTC_REG_POINTER 0x00
unsigned char messageBuf[MESSAGEBUF_SIZE];
unsigned char TWI_DisplaySlaveAddress,TWI_RTCSlaveAddress, temp, pressedButton, myCounter=0;
unsigned char TWI_Act_On_Failure_In_Last_Transmission ( unsigned char TWIerrorMsg )
{
// A failure has occurred, use TWIerrorMsg to determine the nature of the failure
// and take appropriate actions.
// Se header file for a list of possible failures messages.
asm volatile ("nop");
return TWIerrorMsg;
}
unsigned char Reset_RTC()
{
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT);
messageBuf[1] = RTC_REG_POINTER;
messageBuf[2] = 0;
messageBuf[3] = 0;
messageBuf[4] = 0;
messageBuf[5] = 0;
messageBuf[6] = 0;
messageBuf[7] = 0;
USI_TWI_Start_Transceiver_With_Data(messageBuf,8);
return 0;
}
int main( void )
{
char time_array[10];//HH:MM:SS
unsigned char repeat=1;
unsigned char sec,min,hr;
unsigned char i,check=1;
unsigned char mode=0; // mode=0 : Power_Setting ;;;; mode=1 : Time_Setting
int LED_Power=1;
int On_Time=0;
int LED_on=0;
int Duration=0;
int RTC_Seconds=0;
TWI_DisplaySlaveAddress = 0x28;
TWI_RTCSlaveAddress = 0x68;
sei();
USI_TWI_Master_Initialise();
messageBuf[0]=(TWI_DisplaySlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT); // Display an 0x28 schreibend ansprechen
messageBuf[1]=0xFE;
messageBuf[2]=0x53;
messageBuf[3]=8;
USI_TWI_Start_Transceiver_With_Data(messageBuf,4);
// Set PWM-Port PB4
PORTB = 0x00;
DDRB |=(1<<PB4) ; //PWM output pin
TCCR1A |= ((1 << PWM1B)); // Enable Fast PWM for OCR1B
TCCR1C |= ( (1 << PWM1D) ); // Enable Fast PWM for OCR1D
TCCR1C |= ( (1 << COM1D0) ); // OC1D & OC1D^ are connected,Clear on Compare Match
OCR1C = 77;
OCR1D = LED_Power;
//Invert output
TCCR1B |= (1 << PWM1X);
// Start timer1
TCCR1B |= (1 << CS10)|(1 << CS11)|(1 << CS12);
//Switch internal pullups on
PORTA |= (1<<PA7) | (1<<PA6) |(1<<PA5) |(1<<PA4);
PORTB |= (1<<PB6);
Clear_LCD();
for(i=0;i<8;i++)
{
time_array='0';
}
time_array[2]=time_array[5]=':';
/*Convert ASCII to BCD coded data and store in RTC registers*/
for(i=0; i < 8; i++)
{
if ((i==2) || (i==5))
; //do nothing
else
{
time_array -= 48;
}
}
sec = (((time_array[6] << 4) & 0xf0) | (time_array[7]));
min = (((time_array[3] << 4) & 0xf0) | (time_array[4]));
hr = (((time_array[0] << 4) & 0xf0) | (time_array[1]));
/*Write data (time ) in RTC*/
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT);
messageBuf[1] = RTC_REG_POINTER;
messageBuf[2] = sec;
messageBuf[3] = min;
messageBuf[4] = hr;
USI_TWI_Start_Transceiver_With_Data(messageBuf,5);
while(1==1)
{
if (mode==0) // Power_Setting
{
if (!(PINA & 64 ))
{
if (LED_Power>1) LED_Power--;
}
else if (!(PINA & 16 ))
{
if (LED_Power<100) LED_Power++;
}
}
if (mode==1) // Time_Setting
{
if (!(PINA & 64 ))
{
if (On_Time>0) On_Time--;
}
else if (!(PINA & 16 ))
{
if (On_Time<300) On_Time++; // maximale On-time 5min
}
}
if (!(PINA & 32))
{
switch (mode)
{
case 0: mode=1;
break;
case 1: mode=2;
break;
default:mode=0;
break;
}
_delay_ms(200);
}
if (mode==0)
{ SetPos_LCD(0,0);
sprintf(lcd_text,"*Power One %d ",LED_Power);
WriteString_LCD();
SetPos_LCD(0,1);
if (On_Time) sprintf(lcd_text," Real Time %ds ",Duration); else sprintf(lcd_text," On_Time Period ");
WriteString_LCD();
_delay_ms(10);
}
if (mode==1)
{ SetPos_LCD(0,0);
sprintf(lcd_text," Power One %d ",LED_Power);
WriteString_LCD();
SetPos_LCD(0,1);
if (On_Time) sprintf(lcd_text,"*Time One %ds ",Duration); else sprintf(lcd_text,"*On_Time Period ");
WriteString_LCD();
_delay_ms(10);
}
if (!(PINA & 128))
{
_delay_ms(200);
if (LED_on==0) {LED_on=1; Reset_RTC(); RTC_Seconds=0;} else LED_on=0;
if (LED_on) {OCR1D=50; _delay_ms(1);}
}
if (LED_on) OCR1D=LED_Power; else OCR1D=0;
if (LED_on==0)
{
Duration=On_Time;
SetPos_LCD(15,0);
sprintf(lcd_text," ");
WriteString_LCD();
}
else
{
SetPos_LCD(15,0);
sprintf(lcd_text,"*");
WriteString_LCD();
}
if ((LED_on) && (On_Time))
{
if (RTC_Seconds>=On_Time)
LED_on=0;
else
Duration=On_Time-RTC_Seconds;
}
// Set RTC Register
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT);
messageBuf[1] = RTC_REG_POINTER;
USI_TWI_Start_Transceiver_With_Data(messageBuf,2);
// Read RTC Register
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (TRUE<<TWI_READ_BIT);
USI_TWI_Start_Transceiver_With_Data(messageBuf,2);
sec=messageBuf[1];
// Set RTC Register
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT);
messageBuf[1] = 0x01;
USI_TWI_Start_Transceiver_With_Data(messageBuf,2);
// Read RTC Register
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (TRUE<<TWI_READ_BIT);
USI_TWI_Start_Transceiver_With_Data(messageBuf,2);
min=messageBuf[1];
// Set RTC Register
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT);
messageBuf[1] = 0x02;
USI_TWI_Start_Transceiver_With_Data(messageBuf,2);
// Read RTC Register
messageBuf[0]=(TWI_RTCSlaveAddress<<TWI_ADR_BITS) | (TRUE<<TWI_READ_BIT);
USI_TWI_Start_Transceiver_With_Data(messageBuf,2);
hr=messageBuf[1];
// convert time to seconds
RTC_Seconds= (sec & 0x0f) + 10* ((sec >> 4) & 0x0f) // seconds
+ 60*(min & 0x0f) + 600*((min >> 4) & 0x0f); // minutes to secs
// convert BCD coded decimal to ASCII code, display on LCD
time_array[0] = (hr >> 4) & 0x0f;
time_array[1] = hr & 0x0f;
time_array[3] = (min >> 4) & 0x0f;
time_array[4] = min & 0x0f;
time_array[6] = (sec >> 4) & 0x0f;
time_array[7] = sec & 0x0f;
for(i=0; i< 8; i++)
{
if ((i==2) || (i==5))
; //do nothing
else
{
time_array += 48;
}
}
time_array[8]=0;
//SetPos_LCD(0,1);
//sprintf(lcd_text,"Second %s ",time_array);
//sprintf(lcd_text,"seconds %d ",RTC_Seconds);
//WriteString_LCD();
// OCR1B=64;
}
}
