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.