๐Ÿ›’ Device Shopping Lists

Choose a device to see exactly what you need to buy

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Select a Device to Build:

๐Ÿ“ก
EMF Meter
$15-25
โญ Beginner โ€ข 2-4 hours
๐Ÿ“ป
Spirit Box
$35-50
โญโญโญ Intermediate โ€ข 4-6 hours
๐Ÿ—ฃ๏ธ
Ovilus
$50-75
โญโญโญโญ Advanced โ€ข 8-12 hours
โšก
REM Pod
$25-40
โญโญ Easy โ€ข 3-5 hours
๐ŸŽ™๏ธ
EVP Recorder
$30-45
โญโญโญ Intermediate โ€ข 4-6 hours
๐Ÿงธ
BooBuddy
$45-65
โญโญโญโญ Advanced โ€ข 8-10 hours

๐Ÿ“ก EMF Meter Shopping List

Electromagnetic field detector with LED indicators. Perfect first project!

๐Ÿ“‹

Complete Build Guide Available!

Step-by-step wiring guide with terminal blocks, capacitors, and component positioning.

๐Ÿ”Œ View EMF Wiring Guide
8
Components
$15-25
Total Cost
2-4h
Build Time
$40-60
You Save
1ร—

ESP32 DevKit

Main microcontroller board. Get a 3-pack to save money for future builds.

$7-9
Buy on Amazon
5ร—

5mm LEDs (Clear, Blue, Green, Yellow, Red)

Visual indicators for EMF strength progression. Need: 1 clear, 1 blue, 1 green, 1 yellow, 1 red. Get assortment kit with 500+ LEDs.

$2-3
Buy on Amazon
5ร—

220ฮฉ Resistors

Current limiting resistors for LEDs. Get resistor kit with 1000+ pieces.

$1-2
Buy on Amazon
1ร—

Hall Effect Sensor (A3144)

Detects magnetic fields for EMF measurement. Get 10-pack.

$1
Buy on Amazon
1ร—

Terminal Block Strip (12-position)

Screw terminal connections - fits in small enclosure. More compact than breadboard. Needs small screwdriver for assembly.

$3-5
Buy on Amazon
1ร—

Solid Core Wire Kit (22 AWG)

Pre-cut wires in multiple colors for terminal block connections. Get assorted lengths.

$8-12
Buy on Amazon
1ร—

0.96" OLED Display

128x64 I2C display for showing numerical EMF readings.

$3-5
Buy on Amazon
3ร—

Ceramic Capacitors (0.1ยตF)

Power filtering capacitors. ESSENTIAL for stable operation - prevents noise, random resets, and jumpy readings. Get 500-piece kit for all projects.

$10-14
Buy on Amazon
1ร—

Optional (was listed as required): Battery for Portable Use

128x64 I2C display for showing numerical EMF readings.

$3-5
Buy on Amazon
2ร—

18650 Rechargeable Battery + Holder

3.7V lithium battery with holder. Get 2-pack, only need 1 for EMF. Protected cells recommended. Plus single-cell holder with wires.

$12-18
Buy on Amazon
1ร—

TP4056 USB Charging Module

Lithium battery charger with protection. Mounts in lid with USB-C port accessible. Get 5-pack for future projects.

$6-9
Buy on Amazon
1ร—

Micro-USB Extension Cable (3-4", multi-pack)

Short male-to-female extension for ESP32 firmware updates. Stays inside permanently - just pop lid to update. Get 5-10 pack for best value.

$5-10
Buy on Amazon
1ร—

SPDT Slide Switch

On/off power switch. Panel mount slide switch. Get 10-pack for all projects.

$5-7
Buy on Amazon
1ร—

Hot Glue Gun + Glue Sticks

For mounting components inside enclosure. Mini glue gun works great. Essential tool!

$6-10
Buy on Amazon
1ร—

Double-Sided Foam Tape

3M VHB or similar mounting tape. For securing boards inside enclosure.

$5-8
Buy on Amazon
1ร—

USB Cable (Micro-USB or USB-C)

To program ESP32 from computer. Check your ESP32's USB port type. Data cable required (not charge-only).

$4-6
Buy on Amazon
1ร—

Optional: Enclosure for Permanent Build

โš ๏ธ CRITICAL: Hall sensor MUST face forward/up. See assembly guide below for 3 tested case options with drilling templates and finishing tips.

$5-12
Browse Project Boxes

๐Ÿ”ง How to Build It

Option 1: Breadboard Prototype (Recommended for Beginners)

Best for: Testing, learning, and your first build. No soldering required!

  • Insert the ESP32 into the breadboard
  • Connect the Hall Effect sensor with jumper wires
  • Add LEDs with resistors in series (anode โ†’ resistor โ†’ ESP32 pin)
  • Optional: Add the OLED display via I2C (4 wires)
  • Power via USB cable to ESP32

โœ… Total build time: 30 minutes | No tools needed | Fully functional

Option 2: Professional Handheld Enclosure

Best for: Field use, durability, professional appearance

๐ŸŽฏ BEST VALUE - Recommended Case Option A: Pinfox 5-Pack (100x60x25mm)

Dimensions: 3.94" ร— 2.36" ร— 0.98" (100 ร— 60 ร— 25mm) | Price: $10-12 for 5 boxes | Material: Black ABS

Style: Perfect compact handheld size. You get 5 boxes - build multiple devices or have spares!

โ†’ Search: Pinfox 100x60x25mm project box

๐ŸŽฏ Recommended Case Option B: Fielect/Generic ABS Box (100x60x25mm)

Dimensions: 3.94" ร— 2.36" ร— 0.98" | Price: $6-8 (single or 2-pack) | Material: White or Black ABS

Style: Same size as Pinfox, various brands available. Search "100x60x25mm project box"

โ†’ Search: 100x60x25mm ABS enclosure

๐ŸŽฏ Premium Option C: Hammond 1591XXSSBK (Professional Grade)

Dimensions: 4.3" ร— 3.2" ร— 1.7" | Price: $7-10 (single) | Material: Black ABS, IP54 rated

Style: Larger professional-grade enclosure. More space for battery + display. Higher quality but more expensive.

โ†’ Search: Hammond 1591XXSSBK

๐Ÿ“ Assembly Steps
  1. Plan your layout: Mark LED positions on painter's tape (spacing: 0.5" apart for 5 LEDs). Hall sensor faces FORWARD/UP at front edge.
  2. Mark holes with automatic center punch: Creates starter dimple that prevents drill wandering (see techniques below)
  3. Drill LED holes: Use step drill bit to 5mm. Go SLOW - speed causes melting/cracking.
  4. Deburr all holes: Use deburring tool inside and outside each hole until smooth to touch
  5. OLED display (optional): Mark 1" ร— 0.5" rectangle โ†’ Drill corner holes (3mm) โ†’ Connect with jeweler's file โ†’ Sand edges smooth
  6. Test fit components: LEDs should friction-fit snugly. Apply hot glue from inside to secure.

โœ… Build time: 2-3 hours with enclosure

โœจ Professional Finishing Techniques (For ALL Devices)

These techniques work for ANY project box modification - EMF meters, Spirit Boxes, EVP recorders, etc. Based on real-world methods from guitar pedal builders, electronics hobbyists, and DIY communities.

๐Ÿ’ก Read this section BEFORE modifying any enclosure - it will save you time and frustration!

๐ŸŽฏ The #1 Secret: Automatic Center Punch

Why it matters: The difference between amateur and professional drilling is hole placement accuracy. An automatic center punch ($5-8) creates a perfect starter dimple that prevents your drill bit from wandering. Press it against the marked spot, and it automatically creates a precise dimple with spring-loaded force.

Technique: Mark position with pencil โ†’ Apply painter's tape โ†’ Mark again on tape โ†’ Use center punch โ†’ Drill slowly

โ†’ Search: Automatic center punch

๐Ÿ”ฉ Step Drill Bits: The Clean Hole Game-Changer

Why they're essential: Regular twist drill bits crack and melt plastic. Step drill bits (aka unibit) create perfectly clean holes without chatter or cracking. They're THE tool that separates professionals from amateurs.

Best practices:

  • Use titanium-coated step bits for longer life
  • Drill at LOW speed (300-500 RPM if adjustable, or quick trigger pulses)
  • Support the back side with wood block to prevent flex
  • Pull out frequently to clear plastic shavings
  • Stop at each step size to check fit - don't overshoot!
๐ŸŽจ Surface Preparation: The Foundation of Professional Paint

The Pro Method (Used by Guitar Pedal Builders):

  1. Deburr all holes: Use deburring tool inside and outside every hole until glass-smooth
  2. Initial sanding: Wet sand entire surface with 400-grit sandpaper to create tooth for paint adhesion
  3. Clean thoroughly: Wash with dish soap + water, then wipe with isopropyl alcohol (removes oils)
  4. Dry completely: 30+ minutes air dry, or blow dry on cool setting
  5. Primer coats: 2-3 thin coats of plastic primer, 15-20 minutes between coats
  6. Sand primer: Light wet sand with 600-800 grit after primer fully cures (24 hours)

โš ๏ธ Critical: Multiple thin coats beats one thick coat EVERY time. Thick coats drip, sag, and look terrible.

๐Ÿ–Œ๏ธ Painting Techniques from the Community

Spray Paint Method (Most Popular for DIY):

  • Recommended paint: Krylon Fusion (plastic-specific) or Rust-Oleum 2X
  • Distance: Hold can 8-12" away from surface
  • Technique: Light sweeping passes, 50% overlap, keep can moving
  • Coats: 4-6 ultra-thin coats, waiting 10-20 min between each
  • Temperature: Paint in 60-80ยฐF environment (cold = orange peel texture)
  • Cure time: Wait 24+ hours before handling, 72 hours for full hardness

Advanced option - Wet Sanding Between Coats: After 3 coats dry, wet sand with 800-1000 grit, then apply final 2-3 coats. Finish with 1500-2000 grit wet sanding for glass-smooth surface. This is how guitar pedal builders get mirror finishes.

๐ŸŽจ Alternative: Vinyl Wraps (Easier Than Paint!)

Why vinyl is gaining popularity:

  • No spray booth or ventilation needed - cleaner process
  • Instant color change - no waiting for paint to cure
  • Hundreds of colors/patterns including carbon fiber, brushed metal, matte black
  • Removable if you want to change design later
  • Professional results easier to achieve than spray painting

Method: Clean surface with alcohol โ†’ Cut vinyl slightly oversized โ†’ Apply with squeegee from center outward (removes bubbles) โ†’ Heat with hair dryer to conform to curves โ†’ Trim edges with hobby knife โ†’ Seal edges

โ†’ Search: Vinyl wrap sheets (matte black is popular)

๐Ÿ’Ž Premium Option: Powder Coating

The ultra-durable finish: Powder coating gives a car-like finish that's extremely durable and scratch-resistant. Many cities have powder coating shops that will coat small parts for $15-30. Provide them with your drilled/deburred enclosure and specify color. Results are truly professional-grade - this is what commercial paranormal equipment manufacturers use.

Search "powder coating near me" to find local shops. Black, textured black, and OD green are popular paranormal equipment colors.

๐Ÿ› ๏ธ Tools Summary for Professional Finish

Essential ($25-35):

  • Automatic center punch ($5-8)
  • Step drill bit set, titanium coated ($10-15)
  • Deburring tool ($6-10)
  • Sandpaper variety pack: 400, 600, 800, 1000, 1500 grit ($8-12)

Finishing materials ($15-25 per project):

  • Krylon Fusion spray paint or vinyl wrap sheets
  • Plastic primer (if painting)
  • Isopropyl alcohol for cleaning
  • Painter's tape

โœ… Community consensus: The automatic center punch + step drill bits combo is the #1 upgrade that makes DIY enclosures look professional. Everything else is secondary.

EMF Meter Total Cost

$15-25
Save $40-60 vs K2 EMF Meter ($55-85)

Commercial equivalent: K2 EMF Meter, Mel-Meter, Ghost Meter

Prices above are for breadboard version. Add $4-12 for professional enclosure.

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๐Ÿ“ป Spirit Box Shopping List

FM radio scanner with touchscreen interface for rapid frequency sweeping.

8
Components
$35-50
Total Cost
4-6h
Build Time
$30-95
You Save
1ร—

ESP32 DevKit

Main microcontroller with WiFi/Bluetooth capability.

$7-9
Buy on Amazon
1ร—

2.8" ILI9341 TFT Touchscreen

240x320 color touchscreen for interface controls and frequency display.

$12-18
Buy on Amazon
1ร—

TEA5767 FM Radio Module

Programmable FM receiver for frequency scanning (76-108 MHz).

$4-6
Buy on Amazon
1ร—

PAM8403 Audio Amplifier

Mini amplifier module to boost audio output volume.

$2-3
Buy on Amazon
1ร—
8ฮฉ 0.5W Speaker

Small speaker for audio output. 28mm diameter fits most enclosures.

$1-2
Buy on Amazon
1ร—

18650 Battery + Holder

Rechargeable 3.7V lithium battery for portable operation.

$6-9
Buy on Amazon
1ร—

TP4056 Charging Module

USB battery charging circuit with overcharge protection.

$1-2
Buy on Amazon
1ร—

Project Box for Enclosure

โš ๏ธ CRITICAL: You must CUT a 2.5"ร—2" rectangular window in the front panel for touchscreen access. Drill 3-5mm holes for speaker grill. ~4"ร—3"ร—1.5" ABS box.

$5-10
Buy on Amazon

๐Ÿ”ง How to Build It

Spirit Box requires an enclosure as the touchscreen forms the front panel. This is an intermediate build requiring soldering and precision enclosure modification.

Recommended Enclosure

๐ŸŽฏ Best Choice: Hammond 1591XXCSBK

Dimensions: 4.7" ร— 3.2" ร— 1.4" (120 ร— 80 ร— 36mm) | Price: $6-9 | Material: Black ABS

Perfect size for 2.8" touchscreen, battery, and FM module. Professional black finish.

โ†’ Search: Hammond 1591XXCSBK enclosure

๐Ÿ”จ Required Tools

  • For Electronics: Soldering iron, solder, wire cutters, wire strippers
  • For Enclosure: See "Professional Finishing Techniques" in EMF section above for cutting rectangular touchscreen window
  • Essential: Automatic center punch, step drill bits, jeweler's files (for rectangle), deburring tool
  • Assembly: Hot glue gun or small screws for mounting touchscreen

โš ๏ธ The 2.5"ร—2" rectangular cutout for the touchscreen is the hardest part - use the techniques in EMF section above!

๐Ÿ“ Assembly Steps

  1. Prepare enclosure: Mark 2.5"ร—2" rectangle on front โ†’ Drill corners โ†’ Use jeweler's file to connect โ†’ Sand smooth โ†’ Deburr edges
  2. Drill speaker grill: 3-5mm hole pattern (6-8 holes) in front panel for audio output
  3. Drill USB port: 8mm hole in side panel for charging access
  4. Solder FM radio: Connect to ESP32 via I2C (SDA, SCL, VCC, GND)
  5. Connect touchscreen: Wire to ESP32 SPI pins (MOSI, MISO, SCK, CS, DC)
  6. Wire audio: FM module โ†’ PAM8403 amplifier โ†’ Speaker
  7. Install power: Battery โ†’ TP4056 charger โ†’ ESP32 VIN (3.7V)
  8. Mount touchscreen: From inside using hot glue or M2 screws with standoffs
  9. Test before closing: Power on, verify touchscreen, FM radio, and speaker work

โœ… Build time: 4-6 hours | Skill level: Intermediate

๐Ÿ’ก Pro Tips

  • Program touchscreen buttons: "Scan", "Stop", "Sweep Speed +/-" for professional P-SB7-style interface
  • Add 30cm wire antenna externally for better FM reception in the field
  • Use double-sided foam tape to secure battery - allows easy replacement later
  • Label charging port location on outside of case for convenience

Spirit Box Total Cost

$35-50
Save $30-95 vs P-SB7 Spirit Box ($70-145)

Commercial equivalent: P-SB7, P-SB11, SBox Ghost Scanner

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๐Ÿ—ฃ๏ธ Ovilus Shopping List

Environmental sensor-to-word device with phonetic synthesis and LCD display.

10
Components
$50-75
Total Cost
8-12h
Build Time
$250+
You Save
1ร—

ESP32 DevKit

Main microcontroller with ample processing power for phonetic synthesis.

$7-9
Buy on Amazon
1ร—

2.8" ILI9341 TFT Display

Color touchscreen for displaying words and environmental readings.

$12-18
Buy on Amazon
1ร—

BME280 Sensor Module

Temperature, humidity, and barometric pressure sensor for environmental input.

$5-8
Buy on Amazon
1ร—

DFPlayer Mini MP3 Module

Audio playback module for phonetic speech synthesis output.

$3-5
Buy on Amazon
1ร—

MicroSD Card (8GB+)

Storage for phonetic dictionary and audio files (500+ phonemes).

$4-6
Buy on Amazon
1ร—

PAM8403 Audio Amplifier

Amplifier module for clear audio output.

$2-3
Buy on Amazon
1ร—

8ฮฉ 1W Speaker

Small speaker for word playback. 40mm diameter recommended.

$2-3
Buy on Amazon
1ร—

18650 Battery + Holder

Rechargeable battery for portable operation (6-8 hour runtime).

$6-9
Buy on Amazon
1ร—

TP4056 Charging Module

USB charging circuit with protection.

$1-2
Buy on Amazon
1ร—

Enclosure with Screen Window & Speaker Grill

โš ๏ธ CRITICAL: 2.8" display MUST be visible through window. Speaker needs front grill hole for clear word playback. Handheld ~5"ร—3"ร—1.5"

$6-12
Buy on Amazon

๐Ÿ”ง How to Build It

๐Ÿ”จ Required Tools

  • Electronics: Soldering iron, solder, wire strippers, multimeter
  • Enclosure: See "Professional Finishing Techniques" in EMF section for touchscreen window and speaker grill
  • Essential: Step drill bits, jeweler's files, deburring tool, automatic center punch

๐Ÿ“ Assembly Steps

  1. Prepare enclosure: Cut 2.8" display window in front panel, drill speaker grill (8-10 small holes)
  2. Load SD card: Prepare phonetic audio files and word database on microSD card
  3. Connect sensors: Wire BME280 to ESP32 via I2C (SDA, SCL, 3.3V, GND)
  4. Wire display: Connect 2.8" TFT to ESP32 SPI pins
  5. Audio chain: DFPlayer (with SD card) โ†’ PAM8403 amp โ†’ Speaker
  6. Power system: 18650 battery โ†’ TP4056 โ†’ ESP32 VIN
  7. Program ESP32: Upload Ovilus code with sensor-to-word algorithm
  8. Test & calibrate: Verify environmental readings trigger appropriate words

โœ… Build time: 8-12 hours | Skill level: Advanced (requires programming & audio setup)

๐Ÿ’ก Pro Tips

  • Use 500+ word phonetic library - more words = more varied responses
  • Calibrate BME280 sensor readings to meaningful ranges (temp ยฑ5ยฐF, pressure ยฑ0.5 inHg)
  • Display current environmental readings on screen alongside generated words
  • Add session logging to SD card - track which sensors triggered which words

Ovilus Total Cost

$50-75
Save $250+ vs Ovilus V ($300+)

Commercial equivalent: Ovilus V, Ovilus III, ITC Device

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โšก REM Pod Shopping List

Radiating electromagnetic field detector with proximity sensing and multi-color LED alerts.

7
Components
$25-40
Total Cost
3-5h
Build Time
$60-90
You Save
1ร—

ESP32 DevKit

Main microcontroller for field generation and proximity detection.

$7-9
Buy on Amazon
1ร—

MPR121 Capacitive Touch Sensor

12-channel proximity sensor for detecting field disturbances.

$3-5
Buy on Amazon
1ร—

WS2812B LED Ring (12 LEDs)

Individually addressable RGB LEDs for visual proximity indication.

$3-5
Buy on Amazon
1ร—

Piezo Buzzer Module

Active buzzer for audible proximity alerts with varying tones.

$2-3
Buy on Amazon
1ร—

Copper Wire Antenna

20-22 AWG bare copper wire for creating radiating EM field (12" length).

$2-3
Buy on Amazon
1ร—

18650 Battery + Holder

Rechargeable battery for 8-12 hour portable operation.

$6-9
Buy on Amazon
1ร—

Cylindrical Enclosure with Antenna Mount

โš ๏ธ CRITICAL: Copper antenna must extend VERTICALLY from top for 360ยฐ EM field emission. LED ring visible around circumference. Round ~3" diameter

$5-10
Buy on Amazon

๐Ÿ”ง How to Build It

๐Ÿ”จ Required Tools

  • Electronics: Soldering iron (for LED ring and antenna wire)
  • Enclosure: Step drill bits for antenna hole (top) and LED ring visibility (side slots or clear plastic)
  • Essential: Wire stripper, hot glue gun

๐Ÿ“ Assembly Steps

  1. Prepare cylindrical enclosure: Drill hole in top center for vertical copper antenna (12" wire)
  2. LED placement: Mount WS2812B ring around circumference - drill small holes or use clear enclosure
  3. Wire MPR121 sensor: Connect to ESP32 I2C, attach 12" copper wire antenna to sensor input pin
  4. Connect LEDs: WS2812B ring โ†’ ESP32 data pin (with 470ฮฉ resistor)
  5. Add buzzer: Piezo buzzer โ†’ ESP32 PWM pin for varying tones
  6. Power: 18650 battery โ†’ ESP32 VIN (no charger needed - battery lasts 8-12 hours)
  7. Mount antenna vertically: Copper wire extends straight up from top for 360ยฐ EM field
  8. Calibrate proximity: Adjust MPR121 sensitivity for 6-12" detection range

โœ… Build time: 3-5 hours | Skill level: Easy-Intermediate

๐Ÿ’ก Pro Tips

  • Keep antenna wire straight and vertical - coiling reduces field range
  • Program rainbow LED pattern when idle, red flash on detection
  • Add escalating buzzer tones (beeps โ†’ sustained tone) as proximity increases
  • Use heavy base or weighted bottom for stability during investigations

REM Pod Total Cost

$25-40
Save $60-90 vs REM-ATDD ($90-130)

Commercial equivalent: REM-ATDD, REM Pod, Mel-REM

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๐ŸŽ™๏ธ EVP Recorder Shopping List

High-quality digital audio recorder with auto-detection, noise filtering, and timestamped recordings.

๐Ÿ“‹

Complete Build Guide Available!

Step-by-step instructions with wiring diagrams, component positioning, and troubleshooting.

๐Ÿ“– View EMF Wiring Guide
8
Components
$30-45
Total Cost
4-6h
Build Time
$40-155
You Save
1ร—

ESP32 DevKit

Main microcontroller with WiFi for timestamp synchronization.

$7-9
Buy on Amazon
1ร—

MAX9814 Microphone Module

Electret microphone with auto-gain control for clear EVP capture.

$5-8
Buy on Amazon
1ร—

MicroSD Card Module

SD card reader for storing WAV recordings.

$2-3
Buy on Amazon
1ร—

MicroSD Card (16GB+)

Storage for hours of high-quality audio recordings.

$5-7
Buy on Amazon
1ร—

0.96" OLED Display

128x64 display for showing recording status and audio levels.

$3-5
Buy on Amazon
3ร—

Push Buttons

Tactile switches for Record, Stop, and Playback controls.

$1-2
Buy on Amazon
1ร—
18650 Battery + Holder

Rechargeable battery for 10+ hours of recording time.

$6-9
Buy on Amazon
1ร—

Enclosure with Microphone Port & Display Window

โš ๏ธ CRITICAL: Microphone MUST have clear air access (5mm hole or mesh grill). OLED display visible through small window. Handheld ~4"ร—2.5"ร—1"

$4-8
Buy on Amazon

๐Ÿ”ง How to Build It

๐Ÿ”จ Required Tools

  • Electronics: Soldering iron for button connections and wiring
  • Enclosure: Step drill bits for 5mm microphone hole, small holes for buttons, OLED display window
  • Essential: See "Professional Finishing Techniques" in EMF section above

๐Ÿ“ Assembly Steps

  1. Prepare enclosure: Drill 5mm hole for mic (front), small window for OLED, 3 button holes (6-8mm)
  2. Mount microphone: MAX9814 module positioned at front 5mm hole - MUST have clear air access
  3. Wire SD module: MicroSD card module โ†’ ESP32 SPI pins (MOSI, MISO, SCK, CS)
  4. Connect OLED: 0.96" display โ†’ ESP32 I2C (SDA, SCL)
  5. Install buttons: Wire 3 tactile switches to ESP32 GPIO pins with pullup resistors
  6. Microphone wiring: MAX9814 โ†’ ESP32 ADC pin for audio input
  7. Power: 18650 battery โ†’ ESP32 VIN (3.7V)
  8. Program ESP32: Upload EVP recording code with WAV file format, WiFi time sync
  9. Test recording: Verify audio levels on OLED, playback quality, SD card writing

โœ… Build time: 4-6 hours | Skill level: Intermediate

๐Ÿ’ก Pro Tips

  • Program auto-gain control - MAX9814 adjusts to room volume automatically
  • Add visual VU meter on OLED during recording
  • Use WiFi NTP to timestamp recordings accurately (critical for evidence correlation)
  • Format SD card as FAT32 for maximum compatibility with analysis software
  • Include low-battery indicator - recordings corrupted if battery dies mid-session

EVP Recorder Total Cost

$30-45
Save $40-155 vs Digital Recorders ($70-200)

Commercial equivalent: Sony ICD-PX470, Olympus VN-541PC, Zoom H1n

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๐Ÿงธ BooBuddy Shopping List

Interactive bear with EMF, temperature, vibration sensors, motion detection, and phrase playback.

12
Components
$45-65
Total Cost
8-10h
Build Time
$55-105
You Save
1ร—

ESP32 DevKit

Main microcontroller for coordinating all sensors and triggers.

$7-9
Buy on Amazon
1ร—

Stuffed Bear/Animal

Small plush toy (8-12") to house electronics. Hollow or easy to open.

$8-15
Buy on Amazon
1ร—

MPU6050 Gyro/Accelerometer

Motion sensor to detect if the bear is moved or touched.

$3-5
Buy on Amazon
1ร—

Hall Effect Sensor (A3144)

EMF detection sensor for electromagnetic field changes.

$1
Buy on Amazon
1ร—

DS18B20 Temperature Sensor

Digital thermometer for detecting cold spots.

$2-3
Buy on Amazon
1ร—

DFPlayer Mini MP3 Module

Audio playback for pre-recorded phrases and responses.

$3-5
Buy on Amazon
1ร—

MicroSD Card (4GB+)

Storage for audio phrases ("I'm cold", "Did you touch me?", etc).

$3-4
Buy on Amazon
1ร—

8ฮฉ 0.5W Speaker

Small thin speaker that fits inside plush toy.

$1-2
Buy on Amazon
5ร—

RGB LEDs

Color-changing LEDs for eyes or belly indicator lights.

$2-3
Buy on Amazon
1ร—

Vibration Motor

Small coin motor to make the bear vibrate on detection.

$2-3
Buy on Amazon
1ร—

18650 Battery + Holder

Rechargeable battery for 12+ hour investigation runtime.

$6-9
Buy on Amazon
1ร—

TP4056 Charging Module

USB charging circuit - install in discrete location on bear.

$1-2
Buy on Amazon

๐Ÿ”ง How to Build It

๐Ÿ”จ Required Tools

  • Electronics: Soldering iron, wire strippers, heat shrink tubing
  • Fabric work: Seam ripper (to open bear), needle & thread (to close), scissors
  • Essential: Hot glue gun, small screwdriver

๐Ÿ“ Assembly Steps

  1. Prepare stuffed animal: Open seam at back with seam ripper, remove some stuffing to make room for electronics
  2. Load SD card: Prepare audio files ("I'm cold", "Did you touch me?", etc.) on microSD
  3. Wire sensors to ESP32: MPU6050 motion (I2C), Hall effect EMF (digital pin), DS18B20 temp (1-Wire), all share power/ground
  4. Audio system: DFPlayer (with SD) โ†’ Speaker, connect to ESP32 serial
  5. Add RGB LEDs: 5 LEDs positioned in eyes/belly - wire to ESP32 GPIO with resistors
  6. Vibration motor: Small coin motor โ†’ transistor โ†’ ESP32 GPIO (for vibration alerts)
  7. Power system: 18650 battery โ†’ TP4056 charging module โ†’ ESP32 VIN
  8. Position USB port: TP4056 charging port accessible from outside (back seam or belly)
  9. Secure electronics: Hot glue main components to prevent shifting when bear is moved
  10. Close and test: Hand-stitch opening closed, verify motion/EMF/temp triggering correct phrases

โœ… Build time: 8-10 hours | Skill level: Advanced (multi-sensor integration + fabric work)

๐Ÿ’ก Pro Tips

  • Choose bear with removable stuffing (not foam-filled) - much easier to work with
  • Position Hall effect sensor near surface of bear for better EMF detection
  • Program LED color changes: green=idle, yellow=motion, red=EMF, blue=cold spot
  • Add sensor combination triggers: "You moved me AND it's cold" = special phrase
  • Use velcro inside for battery - allows replacement without reopening seam
  • Keep wiring organized with cable ties - prevents tangling when bear moved

BooBuddy Total Cost

$45-65
Save $55-105 vs BooBuddy ($100-170)

Commercial equivalent: BooBuddy Interactive Bear, Cerie Bear

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๐Ÿ’ก Pro Tip: Buy the "Starter Kit" components in bulk (ESP32 3-packs, LED kits, resistor kits) to save money and have parts ready for multiple projects!

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