frequency measurement and display on LCD

[sanam]

Dear reader,

                 could you please provide me code for sampling frequency readings from  555 timer oscillator into ATmega 16 kit. I am finding it difficult to count the frequency reading and display it in the LCD showing the level of water level measurement. From the hardware configuration i a have found frequency reading as follows

at 0cm water level = frequency is 900khz

at 1 cm ,872khz

at 2 cm 864khz

    .

    .

    .

at 30 cm, 435 khz

how can intake this random frequency range into the atmega16 kit and display the output in the LCD.

i would be most grateful for your support and guidance.

Thank you.

[Anonymous]

 

Hi,

       Really interesting project. Could you please tell me how are you generating different frequencies according to the water level using 555 IC ?

[Anonymous]

 

Hi,

       Really interesting project. Could you please tell me how are you generating different frequencies according to the water level using 555 IC ?

[sanam]

Dear reader,

                  Lets say the experiment i am doing is divided into 4 parts like any other measurement device principle: 1) the sensing element, 2)The signal conditioning element 3)signal processing element and software 4)data presentation element.

The sensing element in my experiment is the capacitive co-axial probe that operates using capacitive principle,As you immerse the probe in the water, the di-electric medium in between the 2 electrodes increase further increasing the capacitance. I have connected this probe to a frequency oscillator designed using a 555 timer in astable mode. The sensed signal is enhanced by this oscillator into a frequency domain. The frequency of the signal decreases as capacitance of the probe increases.WE have the relation as,

f =1/(2*pi*(LC)^1/2) for an LC circuit

 

f= 1.44/{(R1+2R2) C} for an RC circuit n this is my circuit and i have designed keeping my own values.

hence, when the probe is immersed in the water at0 cm scale, the frequency received is 872khz,further more as i went on taking the reading,the final point i needed to take is at 30 cm scaling and i received 435khz. So there is a frequency range of 400khz to 900khz.now i need to feed this signal to the ATmega16 controller. Its bit tricky at this point. The data sheet for atmega16 can be found in the internet. I know frequency and time is inversely related and i need to use timers .how ever i am stuck at this point of writing the codes,if anyone could help ma,then please i ask for it ,your effort,guidance and sample codes could lead to my progress.

thanking you 

 

[sanam]

Dear reader,

                  Lets say the experiment i am doing is divided into 4 parts like any other measurement device principle: 1) the sensing element, 2)The signal conditioning element 3)signal processing element and software 4)data presentation element.

The sensing element in my experiment is the capacitive co-axial probe that operates using capacitive principle,As you immerse the probe in the water, the di-electric medium in between the 2 electrodes increase further increasing the capacitance. I have connected this probe to a frequency oscillator designed using a 555 timer in astable mode. The sensed signal is enhanced by this oscillator into a frequency domain. The frequency of the signal decreases as capacitance of the probe increases.WE have the relation as,

f =1/(2*pi*(LC)^1/2) for an LC circuit

 

f= 1.44/{(R1+2R2) C} for an RC circuit n this is my circuit and i have designed keeping my own values.

hence, when the probe is immersed in the water at0 cm scale, the frequency received is 872khz,further more as i went on taking the reading,the final point i needed to take is at 30 cm scaling and i received 435khz. So there is a frequency range of 400khz to 900khz.now i need to feed this signal to the ATmega16 controller. Its bit tricky at this point. The data sheet for atmega16 can be found in the internet. I know frequency and time is inversely related and i need to use timers .how ever i am stuck at this point of writing the codes,if anyone could help ma,then please i ask for it ,your effort,guidance and sample codes could lead to my progress.

thanking you 

 

[sanam]

i would be most grateful if anybody could help me.

Thanking you

[sanam]

i would be most grateful if anybody could help me.

Thanking you

[sanam]

This is my approach but i am not getting anything. could u please help me where am i doing wrong.

Your help and guidance is heartily acknowledged.

 

#include <avr/io.h> 

#include <util/delay.h> 

#include <stdio.h> 

#include <avr/interrupt.h> 

#include <compat/ina90.h>    

 

#include “easyavr_lcd.c”    

 

volatile ov_counter; 

unsigned long frequency; 

 

 

ISR(TIMER1_CAPT_vect) 

{ 

   // Counter to 0 

   TCNT1 = 0; 

  

   // The result is valid only if the counter 

   // has not overflowed yet 

   if (!(TIFR & (1 << TOV1))) 

   { 

      // Calculating the frequency from the period 

      frequency = (unsigned long)8000000 / 

                  (unsigned long)ICR1; 

   } 

    

} 

 

ISR(TIMER1_OVF_vect){ 

   ov_counter++; 

} 

 

void init_timer(){ 

 TCCR1B = (1<<ICES1)  | (1<<CS10); 

  TIMSK = (1<<TICIE1) | (1<<TOIE1); 

} 

 

int main(){ 

  

   DDRB = 0x00; 

  

    

   init_timer(); 

         lcdinit(); 

lcdmsg(“CURRENT LVL”,1); 

 

 

    

char a1[7]; 

    sei(); 

   while(1){ 

lcdmsg(“CURRENT LVL”,1);    

  

    

    itoa(frequency, a1, 10); 

    lcdmsg(a1,2); 

      lcdmsg(“CURRENT LVL”,1); 

      _delay_ms(500); 

   lcdclr(); 

  

   } 

   return 1; 

} 

 

[AJISH ALFRED]

 

The LCD is your only output device; you are not getting means, no display on LCD?

First thing I’ve noted in your code is the refereshing rate. Try giving a bit more delay around 2 seconds before clearing the LCD inside the while loop.

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