Yes it is........uhmmmm no lab jack at my disposal...(use shoe boxes and text books to stack upI am assuming the x-axis is the depth of water in its container. Correct?
1. Graph of Sensor @ fixed distance of 10cm away from glass vessel
2. Graph of Sensor @ fixed distance of 10cm away from glass vessel
3. Graph of Sensor @ fixed distance of 10cm away from glass vessel
distance output V
30 0.509
20 0.724
13 0.725
Let's focus only on water for now -- wine is later
Do you have a cooking pot or aquarium
better labeled charts! )
have used 3 types of the Sharp GP2 sensors with no real stability problems but I had a good +5v supply and short wiring. Lots of people do report erratic readings, (probably noise?). Putting a 10uF cap right at the sensor power between +5v and ground is supposed to help, and also doing some low pass filtering of the analog voltage out would help especially if you have long wires between the sensor and the PIC.
the attached pic shows put a cap from the i/o line to ground.....
would it really make a difference in my readings that i placed the cap right at the sensor power between +5v and ground .....and not as shown in the pic???
#include <pic.h>
#include "pic.h"
#include "delay.h"
#include "math.h"
#include <stdio.h>
#include <stdlib.h> //
void userMenu(char pos); //
void FloatToStr(float , char[]);
void DelayMs(unsigned char);
void lcd_cmd(unsigned char);
void lcd_data(unsigned char);
void lcd_clear(void);
void lcd_puts(const char[]);
void lcd_goto_L1(void);
void lcd_goto_L2(void);
void lcd_cursor(unsigned char);
void lcd_init(void);
void init(void);
char WaitForInput(void);
unsigned char user_input(void);
void home_screen(void);
void EnterHeight(void);
void EnterScreen(void);
void ShowDigits(unsigned char val);
void calc_distance(void);
void main(void);
unsigned char cm2LCD;
unsigned char cmHigh, cmLow;
#define LCD_RS RC0 //LCD RS pin
#define LCD_EN RC1 //LCD EN pin
#define LCD_STROBE() LCD_EN = 1; asm("nop"); asm("nop"); LCD_EN = 0
unsigned char cm10; //
unsigned char cm; //
unsigned int math; // used for voltage calculations
unsigned char NumDec;
unsigned char NumSep[2];
unsigned char i,j,k;
//char temp[8];
//[/b]
unsigned char height=50;
unsigned char range;
unsigned char area;
unsigned char SensorPos=10;
//[/b] New Vars
char input_sw;
char mnuPOS;
unsigned char MyVal;
unsigned char MyValLCD[2];
unsigned char MyMaxVal;
unsigned char MyMinVal;
unsigned long bres; // for bresenham 2-second timer system
unsigned char ;
#define HOME_SW RC2 //HOME switch
#define INCREASE_SW RC3 //INCREASE switch
#define DECREASE_SW RC4 //DECREASE switch
#define ENTERSETTINGS_SW RA4 //ENTERSETTINGS switch
///////////////////////CONVERT FLOAT TO STRING///////////////////
// This function was taken from the CAVR library. It was modified slightly
// to suit our design.
void FloatToStr(float n, char str[])
{
float scale;
unsigned char d,f;
f=0;i=0;
if (n<0.0) {n=-n; str[f]='-'; f++;};
n=n+0.005;
scale=1.0;
while (n>=scale) {scale=scale*10.0; ++i;};
if (i==0) {str[f]='0'; f++;}
else
while (i--)
{
scale=floor(0.5+scale/10.0);
d=(unsigned char) (n/scale);
str[f]=d+'0';
n=n-scale*d;
f++;
};
str[f]='.';
f++;
for (j=0;j<=1;j++) //2 decimal points
{
n=n*10.0;
d=(unsigned char) n;
str[f]=d+'0';
n=n-d;
f++;
};
str[f]='\0';
}
///////////////////END CONVERT FLOAT TO STRING///////////////////
/////////////////////////////DELAY///////////////////////////////
void DelayMs(unsigned char cnt)
{
#if XTAL_FREQ <= 2MHZ
do {
DelayUs(996);
} while(--cnt);
#endif
#if XTAL_FREQ > 2MHZ
unsigned char p;
do {
p = 4;
do {
DelayUs(250);
} while(--p);
} while(--cnt);
#endif
}
void DelayS(unsigned char cnt)
{
for (j=0; j<(cnt*10); j++)
DelayMs(100);
}
///////////////////////////DELAY END/////////////////////////////
//////////////////////////////LCD SETUP//////////////////////////
/* send a command to the LCD */
void lcd_cmd(unsigned char c)
{
DelayMs(2); //wait for LCD to be ready shorter delay
LCD_RS = 0; //write instruction
PORTB = (c & 0xF0); //load upper nibble on LCD data lines
LCD_STROBE(); //send instruction to LCD
PORTB = ((c << 4) & 0xF0); //load upper nibble on LCD data lines
LCD_STROBE(); //send instruction to LCD
}
/* send data to the LCD */
void lcd_data(unsigned char c)
{
DelayMs(2); //wait for LCD to be ready shorter delay
PORTB = 0x00;
LCD_RS = 1; //write data
PORTB |= (c & 0xF0); //load upper nibble on LCD data lines
LCD_STROBE(); //send instruction to LCD
PORTB &= 0x00; //load upper nibble on LCD data lines
PORTB |= ( (c << 4) & 0xF0);
LCD_STROBE(); //send instruction to LCD
}
/*Clear the LCD*/
void lcd_clear(void)
{
lcd_cmd(0x01); //command to clear LCD
}
/*write a string of chars to the LCD*/
void lcd_puts(const char s[])
{
j = -1;
while(s[++j]!=('\0')) // send characters until null character reached
lcd_data(s[j]);
}
/*go to beginning of line 1*/
void lcd_goto_L1(void)
{
lcd_cmd(0b10000000); // command to go to line 1
}
/*go to beginning of line 2*/
void lcd_goto_L2(void)
{
lcd_cmd(0b11000000); // command to go to line 2
}
/*move cursor "x" positions to the right*/
void lcd_cursor(unsigned char x)
{
lcd_cmd(((x)&0x7F)|0x80);
}
/*initialise the LCD - put into 4 bit mode*/
void lcd_init(void)
{
LCD_RS = 0;
LCD_EN = 0;
DelayMs(20); //wait for LCD startup
lcd_cmd(0x02);
lcd_cmd(0x28); // 4-bit mode
lcd_cmd(0x08); // display off
lcd_cmd(0x01); // clear display
lcd_cmd(0x0C); // disp. on, cursor off, cursor blink off
lcd_cmd(0x06); // entry mode
lcd_cmd(0x80); // initialise DDRAM address to zero
}
//////////////////////////LCD SETUP END//////////////////////////
void init(void)
{
// setup the PIC 16f690
OSCCON = 0x72; // internal osc, 8MHz
PORTA = 0;
TRISA = 0b10010010; // RA7 high imp, RA3 is serial out, RA4 button input
PORTB = 0; // PORTB not used
WPUB = 1; // PORTB pullups ON
RABPU = 0;
[COLOR="Red"]
/* Init ADC */
ADCON0 = 0b10000101; // bit 7 right justify,analogue channel select bits bits5-2 0001=AN1,ADC ON, RA1 is ADC input
ADCON1 = 0b00100000; //bits6-4 fosc/32
ADON=1; // turn on the A2D conversion module
ANSEL=0x02; //set RA1 as analog input for GP2 sensor
ANSELH=0x00;
T1CON = 0b00010001; // TMR1 is ON, 1:2 prescale, =1MHz
T2CON = 0b00000101; // TMR2 is ON, 1:4 prescale, =1MHz[/COLOR]
MyVal = 0; //initializn these variables here
MyMinVal = 0;
MyMaxVal = 99;
TRISB=0x00;
TRISC=0xFC;
lcd_init(); //call LCD initialisation
}
char WaitForInput(void){
char done;
char temp;
done = 0;
while(!done){
if(!ENTERSETTINGS_SW){
temp = 1;
done = 0xff;
}
if(!HOME_SW){
temp = 2;
done = 0xff;
}
if(!INCREASE_SW){
temp = 3;
done = 0xff;
}
if(!DECREASE_SW){
temp = 4;
done = 0xff;
}
}//end of while
DelayMs(150); //debounce
return temp;
}//
void userMenu(char pos){
lcd_clear();
lcd_goto_L1();
switch(pos){
case 0:
lcd_puts(" HEIGHT ");
break;
case 1:
lcd_puts(" RANGE ");
break;
case 2:
lcd_puts(" SURFACE AREA ");
break;
}
lcd_goto_L2();
lcd_puts("Press Up/Down"); //home screen message (line 2)
}
// New Menu System
void EnterHeight(void){
lcd_clear();
lcd_goto_L1();
lcd_puts(" ENTER HEIGHT ");
lcd_goto_L2();
lcd_puts("Press Up/Down"); //home screen message (line 2)
}
void EnterScreen(void){
lcd_clear();
lcd_goto_L1();
lcd_puts(" [cm] ");
}
void ShowDigits(unsigned char val){
MyValLCD[0] = val /10; //returns the quotient (if temp = 35 the result is 3)
MyValLCD[1] = val % 10; //Returns remainder (if temp = 35 the result is 5)
MyValLCD[0] += 0x30; //to ASCII
MyValLCD[1] += 0x30; //to ASCII
EnterScreen();
lcd_goto_L2();
lcd_data(MyValLCD[0]); //to LCD
lcd_data(MyValLCD[1]); //to LCD
}
[COLOR="Red"]void calc_distance(void)[/COLOR]
{
// from the transeiver datasheet the analog voltage is
// the inverse of distance, so distance can be calculated
// d = (1 / volts) then just scaled to suit the transeiver
// load ADC value in 16bit math var
math = ADRESH;
math = (math * 256);
math += ADRESL;
// now invert it; (1 / volts) use (6050 / volts) for scaling
math = (6050 / math);
if(math >= 2) math -=2; // fix linear error (-2)
if(math > 99) math = 99; // max limit at 99cm
// convert from 0-99 to 2 decimal digits, 0-99cm
cm10=0;
while(math >= 10)
{
cm10++;
math -= 10;
}
cm = math;
}
//
unsigned char user_input(void) //This will return what we want
{
char done = 0;
MyVal = 0; //Start on 0
while(done == 0){
input_sw = WaitForInput();
switch(input_sw){
case 1:
done = 0xff; //This tells us the user finished entering
lcd_goto_L1();
lcd_puts(" Done! "); //home screen message (line 1)
break;
case 3:
if(MyVal < MyMaxVal)
MyVal++;
EnterScreen();
ShowDigits(MyVal);
break;
case 4:
if(MyVal > MyMinVal)
MyVal--;
EnterScreen();
ShowDigits(MyVal);
break;
default:
break;
}
}
DelayS(1);
return MyVal;
}
void home_screen(void){
mnuPOS = 0;
lcd_clear();
lcd_goto_L1();
lcd_puts("INFRARED LIQUID"); //home screen message (line 1)
lcd_goto_L2();
lcd_puts("LEVEL DETECTOR"); //home screen message (line 2)
input_sw = 0; //Reset the value
while(input_sw != 1) //Wait until enter is pressed
input_sw = WaitForInput();
userMenu(0);
DelayMs(2); //shorter delay
height = user_input(); //The HEIGHT var will have the myVal
userMenu(1);
DelayMs(2); //shorter delay
range = user_input(); //The HEIGHT var will have the myVal
userMenu(2);
DelayMs(2); //shorter delay
area = user_input(); //The HEIGHT var will have the myVal
/*
"enter height"
call enter/settings (which is now user input function in new code)
height=MyVal
"enter range"
call user_input
range=MyVal
"enter surface area"
call user_input
area=MyVal
*/
}
//*********************************************************
/* Junebug_Serial4.c RomanBlack.com 19th July 2009.
uses "zero error 1 second timer"
system to generate a 2 second interval, then every
2 seconds it reads an analog voltage from a
Sharp GP2 distance sensor and converts it to decimal
distance, then sends that data to a LCD
Code for MikroC, config handled by MikroC compiler;
_INTI02_OSC_1H
_WDT_OFF_2H
-MCLRE_ON_3H
_LVP_OFF_4L
_PWRT_ON_2L
*/
//*********************************************************
void main(void)
{
init(); // initialise I/O ports, LCD
while(1){
// home_screen();
[COLOR="Red"]// wait for 2 seconds, uses TMR1 free running at 1Mhz
while(!TMR1IF) // wait for TMR1 overflow
TMR1IF = 0; // clear overflow flag
bres += 65536; // add 65536uS to bres value
if(bres >= 2000000) // if reached 2 seconds!
{
bres -= 2000000; // subtract 2 seconds, keep error
// read the ADC voltage RA1 (Sharp GP2 sensor)
GODONE=1; // initiate conversion on the channel 0
while(GODONE) continue; // Wait convertion done
calc_distance(); // convert ADC value to distance
//CM is higher than 09 so spilt the variable CM into 2
cmHigh = ( ( cm >> 4 ) & 0x0F ) + 0x30;
cmLow = ( cm & 0x0F ) + 0x30;
lcd_data(cmHigh);
lcd_data(cmLow);
[/COLOR]
}
}
}
void main(void)
{
init(); // initialise I/O ports, LCD
while(1){
// home_screen();
// wait for 2 seconds, uses TMR1 free running at 1Mhz
while(!TMR1IF) // wait for TMR1 overflow
TMR1IF = 0; // clear overflow flag
bres += 65536; // add 65536uS to bres value
if(bres >= 2000000) // if reached 2 seconds!
{
bres -= 2000000; // subtract 2 seconds, keep error
// read the ADC voltage RA1 (Sharp GP2 sensor)
GODONE=1; // initiate conversion on the channel 0
while(GODONE) continue; // Wait convertion done
calc_distance(); // convert ADC value to distance
//CM is higher than 09 so spilt the variable CM into 2
cmHigh = ( ( cm >> 4 ) & 0x0F ) + 0x30;
cmLow = ( cm & 0x0F ) + 0x30;//[b]
lcd_clear(); //ADDED THIS[/b]
lcd_data(cmHigh);
lcd_data(cmLow);
} //END OF IF
}//END OF WHILE(1)
}//END OF MAIN
void main(void)
{
init(); //initialise I/O ports, LCD
while(1){
//home_screen();
//wait for 2 seconds, uses TMR1 free running at 1Mhz
while(!TMR1IF); // wait for TMR1 overflow [b] forgot to place ; here[/b]
TMR1IF = 0; // clear overflow flag
bres += 65536; // add 65536uS to bres value
if(bres >= 2000000) // if reached 2 seconds!
{
bres -= 2000000; // subtract 2 seconds, keep error
// read the ADC voltage RA1 (Sharp GP2 sensor)
GODONE=1; // initiate conversion on the channel 0
while(GODONE) continue; // Wait convertion done
calc_distance(); // convert ADC value to distance
//CM is higher than 09 so spilt the variable CM into 2 //[b]
cmHigh = ( cm / 10 ) + '0'; // My Mistake this will get you true
cmLow = ( cm % 10 ) + '0'; // values
lcd_clear(); // ADDED THIS[/b]
lcd_data(cmHigh);
lcd_data(cmLow);
}//END OF IF
}//END OF WHILE(1)
}//END OF MAIN
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