2 layers52.2 × 52.2 mm
Base promicro
google/mozc-devices
Circuit diagrams and firmware source code for Gboard DIY keyboards
30 parts3kApache-2.0
2 layers41.5 × 60.5 mm
Mod sensor agua
TomasOsP/water-flow-sensor-module4-channel 5V→24V opto-isolated flow-sensor→PLC interface — KiCad hardware (CC BY 4.0)
- Size
- 41.5 × 60.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 30
- Nets
- 22
- Pads
- 76
- Tracks, vias
- 72, 0
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 15 Jul 2026
- Updated
- 15 Jul 2026
Overview
Mod sensor agua is an open-source printed circuit board by TomasOsP, from the TomasOsP/water-flow-sensor-module repository on GitHub, published under the CC-BY-4.0 licence. It is a 2-layer board of 41.5 × 60.5 mm with 30 parts on 22 nets, routed with 72 tracks and 0 vias.
Its parts include 8 resistors, 5 connectors, 4 ICs and 4 diodes. It belongs with the sensors and measurement and interfaces and adapters boards of this library.
README
README.mdWater-Flow Sensor Interface Module
A 4-channel, opto-isolated interface board that adapts 5 V flow-meter sensors to the 24 V digital inputs of an industrial PLC. Built for a smart-water-dispenser retrofit, it lets the PLC count pulses from hall-effect flow sensors safely and without ground coupling.
📷 Board photo coming soon. An interactive 3D render is included at
modelos3D/mod_sensor_agua.glb(GitHub renders.glbin the browser — click to rotate).
Overview
The dispenser's flow meters output pulse trains at 5 V, but the PLC's digital inputs expect 24 V logic and must stay galvanically isolated from field wiring. This board bridges the two domains with one PC817 optocoupler per channel: the sensor side drives the opto LED through a current-limiting resistor, and the PLC side pulls a clean 24 V-referenced signal — with an indicator LED per channel for quick visual confirmation that pulses are arriving.
Four independent channels let a single board service all of a machine's flow points. Sensor inputs use keyed JST-XH connectors; power and PLC-side signals land on Phoenix-style terminal blocks for field wiring.
This is the sensor-interface PCB referenced in the Smart Water Dispenser portfolio project.
Key Specs
| Function | 5 V → 24 V opto-isolated pulse interface |
| Channels | 4 (independent) |
| Isolation | Optocoupler per channel (PC817) |
| Sensor input | 5 V hall-effect flow meters, JST-XH 3-pin |
| PLC output | 24 V digital inputs |
| Indication | Status LED per channel |
| Wiring | Phoenix terminal blocks (power + signal) |
| Construction | Through-hole (THT), hand-solderable |
Bill of Materials
| Ref(s) | Value | Qty | Notes |
|---|---|---|---|
| U1–U4 | PC817 | 4 | Optocoupler, DIP-4 |
| R1, R3, R5, R7 | 3 kΩ | 4 | Opto LED current limit (sensor side) |
| R2, R4, R6, R8 | 100 kΩ | 4 | PLC-side pull |
| D1–D4 | LED | 4 | Per-channel status indicator |
| J2–J5 | JST-XH 3-pin | 4 | Flow-sensor inputs |
| J1 | Terminal block 2-pin | 1 | Supply |
| E1–E4 | Terminal block 2-pin | 4 | PLC-side signal out |
A machine-generated CSV is in docs/bom.csv.
Repository Layout
mod_sensor_agua.kicad_pro / .kicad_sch / .kicad_pcb KiCad source (schematic + layout)
docs/water-flow-sensor-schematic.pdf Schematic (PDF)
docs/bom.csv Bill of materials
fab/…-gerbers.zip Gerbers + drill (fabrication)
modelos3D/mod_sensor_agua.glb Interactive 3D board renderManufacturing
The fab/ folder contains a ready-to-send Gerber + drill package. Open the KiCad
project to regenerate outputs or modify the design (KiCad 8+).
License
Hardware design files are released under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt the design, including commercially, as long as you give appropriate credit.
Designed by Tomás Ospina.
Parts
30| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 100k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2, R4, R6, R8 |
| 4 | 3k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R3, R5, R7 |
| 4 | C | TerminalBlock_Phoenix:TerminalBlock_Phoenix_MPT-0,5-2-2.54_1x02_P2.54mm_Horizontal | E1, E2, E3, E4 |
| 4 | LED | LED_THT:LED_D3.0mm | D1, D2, D3, D4 |
| 4 | PC817 | Package_DIP:DIP-4_W7.62mm | U1, U2, U3, U4 |
| 4 | S_In | Connector_JST:JST_XH_B3B-XH-A_1x03_P2.50mm_Vertical | J2, J3, J4, J5 |
| 1 | LOGO | Logo:Logotomas | G*** |
| 1 | Supply | TerminalBlock_Phoenix:TerminalBlock_Phoenix_MPT-0,5-2-2.54_1x02_P2.54mm_Horizontal | J1 |
The 26 most common of 30 parts.
Questions
How big is the Mod sensor agua PCB?
It measures 41.5 × 60.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Mod sensor agua use?
30 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Mod sensor agua KiCad files?
From the TomasOsP/water-flow-sensor-module repository on GitHub, at the commit this page was made from: the board is mod_sensor_agua.kicad_pcb and its schematic mod_sensor_agua.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Mod sensor agua design in my own project?
Its repository publishes it under the CC-BY-4.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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