Building a functional EMF detector from scratch - full guide with parts list

Been tinkering with electronics for years and got fed up paying £80-150 for basic EMF detectors that aren't actually that good. Built my own version for about £35 in parts and it's genuinely more sensitive than commercial options. Thought I'd document the process in case anyone else wants to try.

What you'll need:

- Arduino Uno microcontroller (£18 on Amazon UK)
- EMF sensor coil (can make from copper wire or buy pre-made, £3-8)
- LED display module (£5)
- Power bank or 9V battery (£8-12)
- Basic wire, solder, breadboard (probably have lying around)

Time investment: About 3-4 hours if you've never done this. 1-2 hours if you're comfortable with electronics.

The clever bit: I've programmed the Arduino to log data over time rather than just giving you instant readings. This matters because consistent spikes are more interesting than random fluctuations. Download the code from GitHub at [link] - I've commented it thoroughly so you can modify it.

Build quality honestly rivals £120 commercial detectors. Cost a fraction of the price. Happy to answer technical questions - this is still beta but it works well.

This is fantastic. Been wanting to get into Arduino for investigations but the learning curve seemed steep. Your code looks clear from what I can see on GitHub. Quick question: how sensitive is the coil you're using? Are you getting baseline noise in normal environments or does it mostly register genuine anomalies?

Brilliant guide. Could you add a section about calibration? Might be useful for people who aren't super comfortable with electronics - what counts as a "normal" baseline reading, how to account for local power lines, etc. That would make it more accessible for beginners.

Does it detect AC, DC, or both? Most commercial detectors do AC only which misses a lot of interesting signatures. If yours picks up DC as well, that's a genuine advantage over the expensive stuff.

Cost a fraction of the price

Have you thought about adding wireless data transmission so you could place it remotely and monitor from a distance? That would genuinely improve on commercial options. Could probably do it with a cheap Bluetooth module.

This is exactly what the DIY section should be for. Practical stuff people can actually use. Massive respect for publishing your code openly rather than gatekeeping it. More paranormal investigation should be like this - collaborative and transparent about methodology.