Hardware & Assembly

The recording system is built around an ESP32-DevKitC microcontroller that drives two LED channels (IR + White) via logic-level MOSFETs and reads a DHT22 environmental sensor. This is the standard, recommended setup.

Full step-by-step assembly guide

This page is a quick wiring & pinout reference. The complete assembly instructions (with build photos) are maintained in the project README on GitHub.

Alternative board

An ESP32-S3-BOX-3 (Alternative) with an integrated touchscreen is also supported. It uses different GPIO pins but the same firmware (auto-detected). Use it only if you need the display — for most users the ESP32 DevKit below is the simpler choice.

Required components

Full parts list with ordering links (example vendors — equivalents work too).

1. ESP32 microcontroller

Option A — ESP32-DevKitC (standard, recommended)

• Custom firmware with LED control and sensor support (v2.2 or higher)
• GPIO pins: GPIO 4 (IR LED), GPIO 15 (White LED), GPIO 14 (DHT22)
• Order: AZDelivery ESP32 DevKitC (Amazon)

Option B — ESP32-S3-BOX-3 (Alternative)

• Board with integrated 2.4" touchscreen; requires the ESP32-S3-BOX-3-DOCK for GPIO access
• GPIO pins: GPIO 10 (IR LED), GPIO 11 (White LED), GPIO 12 (DHT22)
• See the ESP32-S3-BOX-3 configuration guide

2. LED system

• IR LED — 850 nm, 12 V (e.g. LED Streifen 2538 120 LED/m IR 850 nm): buyledstrip.com
• White LED — broad-spectrum, 24 V (e.g. 24 V COB 320 L/m iNextStation): Amazon

Different LED voltages

IR and White LEDs run on different voltages (12 V vs. 24 V) — use two separate PSUs and never cross the rails.

3. DHT22 sensor

• Temperature −40…80 °C (±0.5 °C), humidity 0–100 % RH (±2–5 %)
• Board with integrated pull-up resistor (no external resistor needed)
• Order: DHT22 sensor board (Amazon)

4. Power supplies & MOSFETs (logic-level, 3.3 V)

• ESP32 power: 5 V via USB (from the computer)
• IR LED power: 12 V DC, 2–5 A: buyledstrip.com
• White LED power: 24 V DC, 2–5 A: buyledstrip.com
• BOJACK IRLZ34N MOSFET 30 A / 55 V (IRLZ34NPBF): Amazon

Common ground required

A common ground between USB/ESP32 ground and both PSU grounds is mandatory.

5. Connectors, wiring, screw kit

• 3× WAGO 221-413 COMPACT lever connectors (3-conductor): Amazon
• PSU connector DC plug: buyledstrip.com
• 220 Ω resistor (gate series resistor): Elegoo resistor kit (Amazon)
• Magnets: Amazon
• White-light LED connector: Amazon
• Wires and connectors: Amazon
• Glue: Amazon
• Hot glue gun: Amazon
• Screw kit incl. hex keys: Amazon

6. Camera

• Hik Robotics MV-CS-013 60GN (near-infrared) — request via the UC2 company (imprint) or annolution shop
• Product page: hikrobotics.com

7. 3D-printed parts

• See 3D-Printed Parts for all STL/STEP files and print settings.

Pin reference — ESP32 DevKit

GPIO 4  → IR LED MOSFET gate    (PWM, 15 kHz)
GPIO 15 → White LED MOSFET gate (PWM, 15 kHz)
GPIO 14 → DHT22 data            (with 10 kΩ pull-up)
3.3V    → DHT22 VCC
GND     → DHT22 GND, common ground hub (WAGO #W2)

LED system assembly (IRLZ34N MOSFETs)

Each LED channel is switched by one logic-level IRLZ34N MOSFET driven directly from an ESP32 GPIO — no gate driver needed.

MOSFET specifications

• Model: BOJACK IRLZ34N (IRLZ34NPBF)
• Type: N-channel logic-level MOSFET
• Maximum ratings: 30 A, 55 V
• Gate threshold: 1–2 V (logic-level, works with 3.3 V from the ESP32)
• Package: TO-220

Assembled LED driver stage — dual IRLZ34N MOSFETs with WAGO connectors.

MOSFET connection details

1. Gate → ESP32 GPIO (4 or 15) via a 220 Ω resistor
2. Drain → LED connection (−) [12 V for IR, 24 V for White]
3. Source → common ground (WAGO #W2)
4. LED connections:
   • IR LED: (+) from 12 V PSU via WAGO #W1
   • White LED: (+) from 24 V PSU via WAGO #W3
5. DHT22:
   • GND → common ground W2 (or best: directly to ESP32 GND)
   • VCC → 3.3 V at the ESP32
   • Data → GPIO 14

IRLZ34N  (IR LED):                 IRLZ34N  (White LED):
  Gate   → ESP32 GPIO 4   (220 Ω)    Gate   → ESP32 GPIO 15  (220 Ω)
  Drain  → IR LED (−) / 12 V loop    Drain  → White LED (−) / 24 V loop
  Source → common ground (W2)        Source → common ground (W2)

Good to know

• IRLZ34N is logic-level compatible (works with a 3.3 V gate voltage).
• No additional driver circuit is needed between ESP32 and MOSFET.
• PWM frequency: 15 kHz (set in firmware).
• Handles high-power LED strips (up to 30 A theoretical; typically 1–3 A).

Safety notes

• IR LEDs are invisible — use an IR viewer card to verify operation.
• Add a heatsink on the MOSFET if driving >2 A continuous (usually not the case).
• Add a flyback diode (1N4007) across the LED if using inductive loads.
• Ensure a common ground between ESP32, PSUs, and MOSFETs.
• Use appropriately gauged wire for the current loads.

Power distribution (WAGO)

WAGO #W1: 12 V+          → IR LED (+)
WAGO #W3: 24 V+          → White LED (+)
WAGO #W2: common ground  (CRITICAL!)
          ├─ 12 V PSU GND
          ├─ 24 V PSU GND
          ├─ ESP32 GND
          ├─ both MOSFET sources
          └─ both LED cathodes (−)

Common ground is mandatory

The USB/ESP32 ground and both PSU grounds must be tied together at WAGO #W2. Without a common ground the MOSFET gates float and the LEDs will not switch reliably.

DHT22 sensor

• The DHT22 board has an integrated pull-up resistor — no external resistor needed.
• Direct 3-wire connection to the ESP32.
• Use short wires (<40 cm) for reliable communication.

Why 3.3 V (not 5 V)?

The DHT22 datasheet allows 3.3–6 V (5 V optimal), but this setup runs the sensor at 3.3 V for perfect logic-level matching:

• ESP32 GPIO operates at 3.3 V logic ✅
• DHT22 powered at 3.3 V ✅
• Integrated pull-up at 3.3 V ✅
• All signal levels matched ✅

5 V can give marginally more stable readings, but 3.3 V works reliably and avoids any level-shifting. The sensor has been tested extensively at 3.3 V with stable temperature/humidity readings.

Power budget

Component	Voltage	Current	Notes
ESP32	5 V USB	~500 mA	powered from computer
DHT22	3.3 V	1–2 mA	from ESP32 3.3 V pin
IRLZ34N gates (2×)	3.3 V	<1 mA each	logic-level, driven by GPIO
IR LED strip	12 V	1–3 A	via MOSFET, dedicated 12 V PSU
White LED strip	24 V	1–3 A	via MOSFET, dedicated 24 V PSU

Signal specifications

PWM (GPIO 4, 15): 3.3 V logic, 15 kHz, duty 0–100 %, rise/fall <1 µs.

DHT22 (GPIO 14): single-wire digital, 10 kΩ pull-up to 3.3 V, ~0.5 Hz.

Serial: UART over USB, 115200 baud, 8N1, no flow control.

Photos & 3D parts

• Hardware Photos — assembled setup, imager body, mounts.
• 3D-Printed Parts — STL/STEP files and print settings.

Firmware

Flash the ESP32 straight from your browser — no toolchain needed — via the Firmware Installer (Chrome/Edge). Arduino IDE / PlatformIO instructions are in the project README.

Troubleshooting

• ESP32 not detected: use a data USB cable, install CH340/CP2102 drivers, try another port.
• LEDs not switching: check PSU power, verify PWM on the gate (0–3.3 V square wave), confirm common ground.
• DHT22 reads 0.0: confirm 10 kΩ pull-up and 3.3 V, data on GPIO 14 (not GPIO 4).