Do I need ADC chip that will convert analog signals into digital signals. I have one MCP3008

NO. You need to go back to the original problem - buzzer not following the sensor input - and fix that.

I have never known JohnInTX to be wrong before, but maybe today is a first.

Oh, I've been wrong lots but in this case, the linked datasheet for the KY-033 sensor TS is now using shows it as having an analog output..
https://tkkrlab.nl/wiki/Arduino_KY-033_Hunt_sensor_module

 

From your link:

"Analog magnetic sensor module and a digital interface "

Example code seems to be handling digital.

Pity there is no schematic available to be certain

@OP
Please would you post clear pictures of front and back of the module.
Please read and report on the numbers written on top of the 8-pin chip.
Maybe I can construct schematic from pictures - (maybe not)

 

Hexreader's codes are working. I understood here that when the sensor is not active , the led should be off for a 1 seconds

I was not giving time for the LED to go off when the sensor is not active.

 

Example code seems to be handling digital.

int sensorPin = A5; // select the input pin
int ledPin = 13; // select the pin for the LED
int sensorValue = 0; // variable to store the value coming from the sensor
void setup () {
  pinMode (ledPin, OUTPUT);
  Serial.begin (9600);
}
void loop () {
  sensorValue = analogRead (sensorPin);
  digitalWrite (ledPin, HIGH);
  delay (sensorValue);
  digitalWrite (ledPin, LOW);
  delay (sensorValue);
  Serial.println (sensorValue, DEC);
}

I wonder if we hitting the same datasheet?
It's confusing as it says it is an analog Hunt Sensor at the top and it looks like it has an optical sensor but later down it says hall magnetic sensor..

For TS, if the analog swings into the voltage range for a high or low on the digital input, it will read 1 or 0 but what happens in between?

 

Doh...

Why didn't I read code line 9 before making an idiot of myself
Thanks for persevering and correcting me.

Seems today is another good day for you , and a bad day for me.

But all learning is good learning...

Will have a little lie down now, then work on analogue solution when refreshed...

 

Doh...

Why didn't I read code line 9 before making an idiot of myself
Thanks for persevering and correcting me.

Seems today is another good day for you , and a bad day for me.

But all learning is good learning...

Actually I think we've both been snookered.. I just saw a YouTube video that shows the schematic and it has an LM393 comparator output that is low when the indicator light is on. It says it's for a line-follower. But knows what is the reality with these things??

Too bad we can't commiserate over a couple of frosty malts...
Take care.

 

@JohnInTX I just opened a can straight from the fridge. If you do the same then objective achieved virtually/remotely

@OP
Please would you post clear pictures of front and back of the module.
Please read and report on the numbers written on top of the 8-pin chip.
Maybe I can construct schematic from pictures - (maybe not)

Time to find out what module you actually have, not flounder with what the abysmal documentation forces us to guess with

 

I just opened a can straight from the fridge. If you do the same then objective achieved virtually/remotely

Tab *pop!* Southern Star Bombshell Blonde - here's to ya! Mmm.

 

@OP
Please would you post clear pictures of front and back of the module.
Please read and report on the numbers written on top of the 8-pin chip.
Maybe I can construct schematic from pictures - (maybe not)

Time to find out what module you actually have, not flounder with what the abysmal documentation forces us to guess with

Sorry if the picture won't be clear because it's night time. I am finding it difficult to understand the layout.

 

That is good....

Please report on markings of 8-pin IC

Please report on marking of R1. I read "391" - but that makes no sense.

 

Seems like there are plenty of variations of this sensor out there: link

 

That is good....

Please report on markings of 8-pin IC

Please report on marking of R1. I read "391" - but that makes no sense.

Please take a look at picture

R1 391
R2 103
R3 202
LM393 8K1608H

 

I found this searching which seems pretty close to what @Djsarakar has. The component count is right but the descriptors are changed. Also, the sensor elements are interchanged so the comparator sense wiring is incorrect. But otherwise it is closer than the youtube one above.

The IR sensor appears to be a Vishay part. Datasheet is attached.

I redrew the schematic with TS's board nomenclature and values. It makes sense to me.

Some potential issues:
There is no hysteresis on the comparator so expect some oscillation around the setpoint.
The output pullup contains the series indicator LED. That will reduce the '1' voltage by Vf of the LED. TS should measure the output voltage and compare it with Vih(min) for the PIC to see if it's high enough. He could also just add an external pullup 10K-68K to swamp Vf and get the logic high where it needs to be.

Wow. Only 36 more sensors to figure out

 

Some potential issues:
There is no hysteresis on the comparator so expect some oscillation around the setpoint.
The output pullup contains the series indicator LED. That will reduce the '1' voltage by Vf of the LED. He could also just add an external pullup 10K-68K to swamp Vf and get the logic high where it needs to be.

Okay So I have to measure voltage across external resistor. Where should I connect other end of resistor. I think it should be connect to ground

TS should measure the output voltage and compare it with Vih(min) for the PIC to see if it's high enough.

What is Vih (min)?

 

Vih(min) is the minimum voltage required on an input to guarantee a logic 1 will be read. On your PIC, it is Vdd * .8 = 4 volts assuming Vdd is 5V.

Okay So I have to measure voltage across external resistor. Where should I connect other end of resistor. I think it should be connect to ground

It is a pull UP to Vcc and you measure the voltage from the output to ground.

 

. TS should measure the output voltage and compare it with Vih(min) for the PIC to see if it's high enough. He could also just add an external pullup 10K-68K to swamp Vf and get the logic high where it needs to be.:

I have added 30k pull up resistor.
I have measured 2.93 volt across resistor when object is in front of sensor

And 0 volt when there is no object in front of the sensor

 

The resistor is connected incorrectly.
Post #36

 

The resistor is connected incorrectly.
Post #36

Sorry for wrong connection

I have measured 4.90 volt across resistor when object is in front of sensor

And 0.10 volt when there is no object in front of the sensor

 

I have measured 4.90 volt across resistor when object is in front of sensor
And 0.10 volt when there is no object in front of the sensor

That's better.
Now, remove the pull up resistor temporarily. What are the high and low voltages?

 

That's better.
Now, remove the pull up resistor temporarily. What are the high and low voltages?

0.10 volt when object is in front of sensor

And 3.42 volt when there is no object in front of the sensor