ET-S02
SCD41 True CO₂ Sensor
Photoacoustic NDIR CO₂ plus temperature and humidity
AED 159.00
Out of stockOverview
Photoacoustic NDIR CO₂ plus temperature and humidity
The ET-S02 is built around the Sensirion SCD41 — CO₂ 400–5000ppm ±(40ppm+5%), plus T/RH. It connects over I²C (fixed 0x62) and is powered from VIN 3.3–5.5V (5V recommended), dedicated 3.3V LDO.
Two Qwiic / STEMMA QT connectors let you chain it with other boards without soldering, and the 2.54 mm header fits a breadboard.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- Indoor air-quality monitors
- Ventilation control in classrooms and offices
- Greenhouse CO₂ logging
Key features
What makes it different
Sensor
Sensirion SCD41: CO₂ 400–5000ppm ±(40ppm+5%), plus T/RH
Interface
I2C, fixed 0x62
Supply
VIN 3.3–5.5V (5V recommended), dedicated 3.3V LDO
Current
15mA average, 205mA peak at 3.3V
Qwiic / STEMMA QT
Two JST-SH connectors plus a 2.54 mm header — 3.3 V and 5 V hosts.
Open documentation
Schematic, BOM and layout notes published for every board.
Specifications
Technical specifications
| Sensor | Sensirion SCD41: CO₂ 400–5000ppm ±(40ppm+5%), plus T/RH |
|---|---|
| Interface | I2C, fixed 0x62 |
| Supply | VIN 3.3–5.5V (5V recommended), dedicated 3.3V LDO |
| Current | 15mA average, 205mA peak at 3.3V |
| Size | 25.4 × 17.8 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 2 × Qwiic / STEMMA QT (JST SH 4-pin) · 5-pin 2.54 mm header |
| Main IC | SCD41-D-R2 (LCSC C3659294) |
| Revision | Rev B |
| Libraries | Sensirion arduino-i2c-scd4x, Adafruit_SCD4x / CircuitPython, ESPHome scd4x |
|---|
| JP1 (default Closed) | Cut to turn off the LED (lowers self-heating) |
|---|---|
| JP2 (default Closed) | Cut to remove the host-side pull-ups |
Performance
Power draw by measurement mode
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | Power | 3.3–5.5V (use 5V for the best margin) |
| 2 | 3V3 | Power | LDO output, don't load |
| 3 | GND | Ground | Ground |
| 4 | SCL | I²C | I²C clock |
| 5 | SDA | I²C | I²C data |
Qwiic / STEMMA QT pins: GND, VIN, SDA, SCL (same on both connectors). I²C pull-ups (10 kΩ) are on the board; cut JP2 to remove them.
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-S02 SCD41 True CO₂ Sensor (assembled)
- 1 × 5-pin 2.54 mm male header, unsoldered
Getting started
- Plug in a Qwiic / STEMMA QT cable, or solder the header and wire VIN, GND, SDA and SCL
- Libraries: Sensirion arduino-i2c-scd4x, Adafruit_SCD4x / CircuitPython, ESPHome
scd4x - Run an I²C scanner to confirm the address: 0x62
Compare
Which air-quality sensor?
| SCD41 True CO₂ Sensor (this board)This board | ET-S13 SGP41 VOC & NOx Sensor | ET-S14 PMS5003 Particulate Sensor Carrier | ET-S12 BME688 Gas & Environmental Sensor | |
|---|---|---|---|---|
| What it does | Photoacoustic NDIR CO₂ plus temperature and humidity | Sensirion VOC and NOx index gas sensor | PM1.0 / PM2.5 / PM10 carrier with level-shifted UART | VOC gas plus temperature, humidity and pressure |
| Interface | I²C, fixed 0x62 | I²C, fixed 0x59 | UART 9600 8N1 + SET (sleep) + RESET | I²C 0x77 / 0x76 (JP3) |
| Best for | Indoor air-quality monitors | Air purifier control | Dust and smoke monitoring | Indoor air-quality nodes |
| Price | 159 AED | 49 AED | 25 AED | 59 AED |
Downloads
Documents and design files
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