ET-S46
Isolated EC / TDS Interface
Isolated conductivity front end (AD5933), BNC
AED 219.00
Out of stockOverview
Isolated conductivity front end (AD5933), BNC
The ET-S46 is built around the ADI AD5933 — on-chip DDS excitation 1Hz–100kHz, 12-bit 1MSPS ADC, DFT → real/imaginary impedance over I2C. It connects over I²C 0x0D (fixed) and is powered from 5V on VIN.
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
- Hydroponic nutrient control
- Water-quality and TDS monitoring
- Aquarium salinity
Key features
What makes it different
IC
ADI AD5933: on-chip DDS excitation 1Hz–100kHz, 12-bit 1MSPS ADC, DFT → real/imaginary impedance over I2C
Function
AC conductivity measurement (no electrode polarization), 1–10kHz excitation, K=1 probe ≈ 0.1–20 mS/cm with R8 = 1k
Isolation
Same isolated front end as S45: pH + EC in one tank without interference
Interface
I2C 0x0D (fixed)
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
| IC | ADI AD5933: on-chip DDS excitation 1Hz–100kHz, 12-bit 1MSPS ADC, DFT → real/imaginary impedance over I2C |
|---|---|
| Function | AC conductivity measurement (no electrode polarization), 1–10kHz excitation, K=1 probe ≈ 0.1–20 mS/cm with R8 = 1k |
| Isolation | Same isolated front end as S45: pH + EC in one tank without interference |
| Interface | I2C 0x0D (fixed) |
| Supply | 5V on VIN |
| Size | 50.8 × 25.4 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 2 × Qwiic / STEMMA QT (JST SH 4-pin) · 4-pin 2.54 mm header · BNC female R/A 50Ω PCB (THT) — EC probe BNC |
| Main IC | AD5933YRSZ (LCSC C578324) |
| Revision | Rev B |
| Libraries | AD5933 Arduino libraries (mjmeli/AD5933), EC/TDS conversion + calibration example (ElectroTrical) |
|---|
| JP1 (default Closed) | Cut to turn off the LED |
|---|---|
| JP2 (default Closed) | Cut to remove the host-side I2C pull-ups |
Performance
Typical readings
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | Power | 5V required |
| 2 | GND | Ground | Ground |
| 3 | SCL | I²C | I²C clock |
| 4 | 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-S46 Isolated EC / TDS Interface (assembled)
- 1 × 4-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: AD5933 Arduino libraries (mjmeli/AD5933), EC/TDS conversion + calibration example (ElectroTrical)
- Run an I²C scanner to confirm the address: 0x0D
Compare
Which water-quality board?
| Isolated EC / TDS Interface (this board)This board | ET-S45 Isolated pH Probe Interface | ET-S10 FDC1004 Capacitive Soil Moisture Probe | |
|---|---|---|---|
| What it does | Isolated conductivity front end (AD5933), BNC | Galvanically isolated 18-bit pH front end, BNC | Corrosion-proof capacitive soil probe with I²C |
| Interface | I²C 0x0D (fixed) | I²C 0x68 (MCP3421A0) | I²C fixed 0x50 |
| Best for | Hydroponic nutrient control | Hydroponics and aquariums | Plant and garden monitoring |
| Price | 219 AED | 219 AED | 23 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.