ET-S18
AS3935 Lightning Detector
Detects lightning up to 40 km away
AED 89.00
Out of stockOverview
Detects lightning up to 40 km away
The ET-S18 is built around the ScioSense AS3935 — lightning detection to 40km, 14-step distance estimate, disturber rejection. It connects over I²C (address 0x00–0x03) or SPI; this board uses I²C and is powered from VIN 2.4–5.5V direct.
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
- Storm early warning
- Outdoor equipment protection
- Weather station add-on
Key features
What makes it different
Sensor
ScioSense AS3935: lightning detection to 40km, 14-step distance estimate, disturber rejection
Interface
I2C (address 0x00–0x03) or SPI; this board uses I2C
Supply
VIN 2.4–5.5V direct
Antenna
Coilcraft MA5532-AE 100µH ferrite tuned to 500kHz
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 | ScioSense AS3935: lightning detection to 40km, 14-step distance estimate, disturber rejection |
|---|---|
| Interface | I2C (address 0x00–0x03) or SPI; this board uses I2C |
| Supply | VIN 2.4–5.5V direct |
| Antenna | Coilcraft MA5532-AE 100µH ferrite tuned to 500kHz |
| Size | 38.1 × 25.4 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 | AS3935-BQFT (LCSC C3178344) |
| Revision | Rev B |
| Libraries | SparkFun AS3935 Arduino library, DFRobot AS3935, ESPHome as3935_i2c |
|---|
| JP1 (default Closed) | Cut to turn off the LED |
|---|---|
| JP2 (default Closed) | Cut to remove the host-side I2C pull-ups |
| JP3 (default 1–2 (high)) | ADD0 select |
| JP4 (default 1–2 (high)) | ADD1 select → default address 0x03 |
Performance
Distance estimates
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | Power | Sensor supply = host logic level |
| 2 | GND | Ground | Ground |
| 3 | SCL | I²C | I²C clock |
| 4 | SDA | I²C | I²C data |
| 5 | IRQ | Output | Active-high interrupt (lightning / disturber / noise) |
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-S18 AS3935 Lightning Detector (assembled)
- 1 × 5-pin 2.54 mm male header, unsoldered
- 1 × MA5532-AE 100µH lightning antenna (consigned)
Getting started
- Plug in a Qwiic / STEMMA QT cable, or solder the header and wire VIN, GND, SDA and SCL
- Libraries: SparkFun AS3935 Arduino library, DFRobot AS3935, ESPHome
as3935_i2c - Run an I²C scanner to confirm the address: 0x00, 0x03
Compare
Which weather add-on?
| AS3935 Lightning Detector (this board)This board | ET-S01 BME280 Environmental Sensor | ET-S15 BMP390 Precision Barometer | |
|---|---|---|---|
| What it does | Detects lightning up to 40 km away | Temperature, humidity and pressure, Qwiic + header | High-precision pressure and altitude, ±0.03 hPa |
| Interface | I²C (address 0x00–0x03) or SPI; this board uses… | I²C, 0x77 default / 0x76 (JP3) | I²C 0x77 / 0x76 (JP3), INT |
| Best for | Storm early warning | Weather stations and data loggers | Drone and rocket altimeters |
| Price | 89 AED | 49 AED | 39 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.