Reading the EMF inputs for EMF Detector for Underground Armoured Cables

Greetings,

I am currently working on my final year project which is on developing an EMF Detector for Underground Armoured Cables. This hand-held device will function in such a way whereby it could detect if the underground cable is live or dead besides also recording the very information in a SD Card via Arduino Data Logger. The sole purpose of developing this prototype is to ensure the personnel on site does not make a mistake by cutting the wrong underground cable during his maintenance work.

The primary sensor of this project which works on components like the 100mH inductor (used as sensor), two pieces of MC1458 Dual Op Amp and other related components. The audio output is good whereby the detector could detect the minute excretion of EMF from the armoured cable. The signal is then connected to LM3915 IC whereby the output is also then shown via LEDs'.

The signal is also transmitted thru Arduino to be logged into the data logger. A simple message of 'Live' or 'Dead' should be programmed upon detecting the EMF from the cable. For an example, a strong signal should prompt Arduino to recognize it as live while minimum signal should be identified as 'Dead'. Unfortunately, I am currently facing a problem whereby the input that i receive from the serial monitor is very close and sometimes does not show any difference in terms of the resolution with or without the contact of the underground cable. The audio seems to work fine where upon contact the audio sound is loud while away, it is significantly low. I am confused why am I not receiving a similar pattern in the arduino serial monitor?

Please excuse my poor English, kindly let me know if you have any doubts in my question. I would really appreciate if you guys could help me with this problem.

Thank You.

Your English is very good! I like your phrase "minute excretion of EMF ". Never though of it that way!

You gave lots of information, but nothing about how the Arduino is involved, how it is connected , or a copy of the code you think should be doing something, but is dong something different.

Paul

Paul_KD7HB: Your English is very good! I like your phrase "minute excretion of EMF ". Never though of it that way!

You gave lots of information, but nothing about how the Arduino is involved, how it is connected , or a copy of the code you think should be doing something, but is dong something different.

Paul

I am so sorry, I am so lost with words..anyways, the entire circuit is connected as shown in the following pictures. I am connecting the analog input from pin 7 ( written Arduino in the circuit ) to analog input A0 along with a common ground connection. So, as of for the start, I used this simple code that I found from the net, just to check on if the arduino could read the input from the EMF sensors (100mH inductors).

The following is the code;

int sensePin =0;

int val = 0;           // variable to store the value read


void setup() {
  analogReference(DEFAULT);

   
  Serial.begin(9600);
  

}

void loop() {

   val = analogRead(sensePin);    // read the input pin
  delay(500);
  Serial.println(val);             // debug value

}

However i found the results to be rather confusing as the readings/resolutions did not make significant change with or without the contact of the armoured cable.

Below is the reading I got from the serial monitor; * Note: the readings did not make difference with or without the contact of the armoured cable, it constantly fluctuates with drastic increase or sometimes with minimum fluctuation however I could not conclude as the reading is pretty much the same, but the audio output from the earphone is pretty clear with the difference.

Results from the serial monitor;

223 224 227 279 231 229 229 228 228 216 223 227 324 386 223 224 224 229 535 536 385 236 231 228 228 276 629 392 402 338 365 639 606 666 629 642 650 598 631 635 636 632 635 634 640 662 649 654 477 482 515 233 236 230 234 235 228 232 236 232 227 229 232 226 220 222 224 224 236 232 232 230 229 230 228 228 232 230 228 230 229 229 226 229 230 235 226 231 231 231 230 225 226 226 226 224 235 227 224 225 227 227 227 224 313 352 640 644 650 641 641 610 667 639 652 647 615 647 647 643 647 631 640 648 652 641 648 644 646 647 645 652 620 601 234 232 237 232 232 235 231 232 231 232 231 231 232 237 231 234 232 226 230 230 229 229 232 230 235 235 232 230 235 233 234 233 233 232 233 233 235 233 233 234 234 234 233 233 232 232 236 232 233 233 233 233 233 231 233 233 233 227 230 223 226 225 225 227 227 224 228 226 228 228 227 227 230 230 228 230 228 229 229 230 229 228 229 230 226 233 226 227 228 229 228 225 228 227 228 228 231 230 232 234 232 239 233 233 227 232 232 234 232 233 231 234 228 232 232 228 223 228 225 224 226 226 212 227 233 226 235 239 219 227 233 223 228 229 240 242 234 237 232 239 228 230 232 242 242 248 235 233 235 239 236 240 239 234 234 239 234 237 235 162 0 0

Hope that helps, kindly please let me know, if you require any further information. I am using the Arduino for the first time, so I am kinda lost, please kindly bare with me.

Thank You.

Image :

Your list of stuff from the monitor is a waste of space.

Do you understand the sensor will produce AC, alternating current? The Arduino can only measure DC voltage. Do you have a circuit connected to the sensor to rectify and filter the AC and make it DC that can be measured? If so, what is the voltage produced?

Paul