Waaaay Off Topic Electronics Hobby - The Whisper Box

NateS · February 20, 2026, 3:17pm

Let me preface this with a bit of a caveat. I don’t believe in ghosts, spirits or an afterlife. But I am not so stubborn that I couldn’t be convinced otherwise. If you’re coming with strong claims of ghosts, then Imma need some strong evidence.

My girlfriend watches a lot of ghost hunter shows, and I simply can’t stand them. They have these random LEDs that light up, or speakers that play radio clips to indicate ghosts. It is all crap and all for show, but they have some people convinced. I said, I could make a better sensor than that, and she said, prove it.

Enter The Whisper Box.

This is a project that combines virtually every sensor I could get my hands on, into a single detector. The sensors include:

60GHz MMwave Presence detector
3 x Ultrasonic distance sensors
3 x MEMS accelerometers
PIR motion detector
Flame IR sensor
MEMS barometric pressure sensor
DHT11 Temp/Humid sensor
a variety of other types of temperature sensors
a variety of Hall magnetic sensors
a suite 9 of MQ gas sensors (MQ2-9, MQ135)
a 2.5um particle detector
a custom orthogonal capacitive environment sensor
Omnidirectional microphone

These sensors are all gathered with a few raspberry pi picos. That data is streamed out over USB via serial. All the picos are piped into a raspberry pi 4, that handles the visualizations and output.

Our thinking is that if a ghost exists, and it has any ability at all to interact with the environment, then this gives the ghost the ability to interact with a device that can translate interactions into readings. MEMS devices in particular are sensitive to very small movements. The custom capacitive sensor is extremely sensitive and can detect me bobbing my head over 2 meters away! If the spirits have any intention to communicate, this would be the way they could do it electronically. To use the device, follow a simple procedure of asking your spirit a question, then observing the readings for a response. We can get into correlation later.

I have no expectation of finding spirits with this device. I figured that if nothing else, it is a good way to keep my brain working, use up all these components I have laying around, and maybe give me a way to relate to Lisa when she starts talking about ghost hunting, without rolling my eyes.

I am still deep in the process of designing and building it. I thought this would be the perfect project to get my own custom PCB manufactured. All the youtubers say its only $5 for 5 boards. I got my MQ gas sensors all laid up into a single PCB with multiplexing over I2C, dedicated power filtering, and a nice classy look. When I uploaded the files I was happy to see the cost was right around what I expected. As I moved through the process and got to the very end, they tacked on VAT and tariff charges that took my $5 order to over $50! That was enough to make me back off and do it myself the hard way.

Here’s a couple of shots showing off the mess I’ve gotten myself into.
MQ Gas Sensor Array

Orthogonal Capacitive Sensor

Triple 3-axis accelerometers

MMwave and ultrasonic sensors

I still have more sensors to add. I still need to design and build a case to hold it all. I still need to design the interface.
I’d like to find a good cheap infrasound mic. I’d also like to find an affordable Geiger tube to add on.
Anyone else into electronics? How would you go about detecting a ghost?

JMPCONJ · February 20, 2026, 3:24pm

That’s pretty cool stuff. I haven’t gone near circuit board stuff since college. Then again I can’t say I miss it much.

And just for spits and giggles, a little comic relief. Trying to lighten my mood on a damp, dreary, dismal Friday at the end of a gawdawful week.

Who Ya Gonna Call GIFs | Tenor

BONUS EDIT: and for those with somewhat louder musical tastes

dcamlin · February 20, 2026, 3:31pm

My initial thought was, with the sensitivity of some of your sensors:

Unless you’re going to run this like a Radon test where you set it up and then vacate the area for a period of time and hope a ghost happens to stumble through… I’m assuming you’d want an “observer” (someone to ask the potential specter questions and wait for a response, for example). How do you filter out readings created by the observer themselves?

Not criticizing anything you’re doing! Not a ghost chaser/believer myself. But intrigued by all your work!!

If nothing else, you’ll be able to hear if you have any termites chewing on your rafters, or mice running around!

dr_dan · February 20, 2026, 3:39pm

I just want to give you a pat on the back. First, you are seeking a way to connect with your significant other on a topic that could easily become divisive. If you have that wiring in place in your brain, you’re better off than probably 90% of people. This forum doesn’t get into that topic very much but it’s ironic how much the things that make people like us good at our jobs can be a hindrance to successful relationships.

Also, as a believer in the spiritual myself, I have read so many testimonies/stories of former non-believers who set out just as you are doing intending to prove otherwise or if, possible, to prove without a doubt that they do exist. Go for it. I’m excited to hear how it goes. I don’t have much to offer in the way of advice but I do offer my support and encouragement to pursue it. I hope you report back progress.

NateS · February 20, 2026, 3:39pm

That’s a great question and one that will be important to solve. I think that procedure is the solution to this.

The device will have the table-top radio form factor. So You set the device on the table or on the floor, and point it at an otherwise empty room. The sensing area is intended to be mostly in front of the device, with screens on the back so you can see the readings. However, that capacitive sensor is certainly sensitive enough to get movement behind the device. I think its a good thing that you can set it off with small movements. It forces you to sit still and quiet.

dr_dan · February 20, 2026, 3:43pm

That, in and of itself, is part of why I believe in the spiritual. You would miss a lot if you weren’t actively seeking it out and those signals are easy to mistake for everyday noise. My little tagline thing on my profile is sort of lent to this experiment. You find that which you seek!

Randy · February 20, 2026, 3:44pm

Is there any way to adjust or point it’s sensitivity? I never got into electronics past a single class in Middle School so sorry if my question is ignorant.

As one who doesn’t believe in ghosts either, I’m fascinated by your project and curious what you’ll find.

dr_dan · February 20, 2026, 3:46pm

I think just getting into it will teach you what you need to adjust. It’s good to have an idea of it going in but there’s nothing about it that can’t be adjusted or redesigned once he gets started. I don’t know how most of that stuff works but in any design there’s usually a feedback loop that should be able to make adjustments as needed… Hysteresis? It that the right word?

NateS · February 20, 2026, 3:50pm

Yes, with clever ground plane placements I can sort of shield the sensing region.

NateS · February 20, 2026, 3:54pm

That’s a bit different, but yes. I can tune everything about it. The hard part is deciding how sensitive to make every sensor. Separating the noise floor from real data, and showing it in a meaningful way. We are starting to get into statistics.

Hysteresis is the property where the signal lags behind the thing causing it. The classic example is like when you bring a magnet near something that field is induced in that object. The time it takes to induce that magnetic field is the hysteresis time.

klincecum · February 20, 2026, 4:04pm

Doug.C · February 20, 2026, 4:08pm

Great, now the Everly Brothers are in my head…

klincecum · February 20, 2026, 4:29pm

I’m feeling a bit more Righteous…

Clicky, Clicky…

Doug.C · February 20, 2026, 4:42pm

Man, I do that all the time with groups…

kananga · February 20, 2026, 5:12pm

Just don’t go in there or Noel Fielding will get out!

Scared It Crowd GIF

Chris_Conn · February 20, 2026, 5:14pm

As a nerd and software\hardware guy, I love it.

d_inman · February 20, 2026, 7:13pm

RadioShack…

Theres A Name Ive Not Heard In Many Years GIF - Theres A Name Ive Not Heard In...

NateS · February 20, 2026, 7:17pm

I miss being able to walk into a store and open a drawer to search for the parts I need. Our Radioshack closed in the early 2000s. I dream of opening a hobby electronics shop akin to Radioshack.

kananga · February 20, 2026, 8:10pm

I miss all the amazing local surplus electronic shops too, those shops smelled just like disassembling old electronics. Surplus Gizmos somehow still exists to provide that whiff of pure carcinogenic nostalgia.

Internet classified wiped out the rest. There’s nowhere in the market for $10 10-amp variacs when the option exists to spray paint it and post a listing on Ebay and Craigslist for $5000 where it will live unsold until their disgruntled heirs throw it away.

jbooker · February 20, 2026, 8:10pm

Very cool project.

Check out cylon.js if you want to abstract io away to a browser UX.

Like:

const Cylon = require("cylon");
Cylon.robot({
  name: "ghostbox",
  connections: {
    raspi: { adaptor: "raspi" }
  },
  devices: {
    pir: { driver: "direct-pin", pin: 7, connection: "raspi" },
    led: { driver: "led", pin: 11, connection: "raspi" }
  },
  events: \["telemetry"\],
  work: function (my) {
    setInterval(() => {
      const motion = my.pir.digitalRead ? my.pir.digitalRead() : 0;
      if (motion) {
        my.led.turnOn();
      } else {
        my.led.turnOff();
      }
      this.emit("telemetry", {
        ts: Date.now(),
        pir: motion
      });
    }, 200);
  }
});
Cylon.api("socketio", { host: "0.0.0.0", port: 3000 });
Cylon.start();