2 layers85.1 × 53.3 mm
Receiver
mvanbrab/water-level
A project to measure the water level in a water reservoir, using a waterproof ultrasonic sensor
17 parts5
2 layers85.1 × 53.3 mm
Transmitter
mvanbrab/water-level5A project to measure the water level in a water reservoir, using a waterproof ultrasonic sensor
- Size
- 85.1 × 53.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 23
- Nets
- 45
- Pads
- 90
- Tracks, vias
- 160, 2
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 12 Feb 2020
- Updated
- 19 Sep 2026
Overview
Transmitter is an open-source printed circuit board by mvanbrab, from the mvanbrab/water-level repository on GitHub. It is a 2-layer board of 85.1 × 53.3 mm with 23 parts on 45 nets, routed with 160 tracks and 2 vias.
It is built around the MAX3232ID. Its parts include 10 capacitors, 4 ICs, 3 connectors and 2 diodes.
Main components
1README
README.mdIntroduction
Here I share hardware and software about my water-level project, whose purpose is to measure the water level in a water reservoir, located under the ground.
This project actually has a predecessor. Enjoy reading about it in this bit of history.
The transmitter
The first piece of hardware is a transmitter. It measures the water level with a waterproof ultrasonic sensor and sends the measurement result as a JSON object via RS232 to a possibly connected receiver.
The positioning of this sensor in my project is described in the physical setup.
Here are some pictures showing the transmitter in practice.
In the folder hardware/transmitter you'll find the hardware design as a KiCad project. Without Kicad installed, you can view
- the schematic diagram as .pdf;
- the copper layout of the printed circuit board;
- the component placement on the printed circuit board.
The folder software/WaterLevelTransmitter is an Arduino sketch, containing the software of the transmitter part of the project.
Read more about this piece of software here.
The receiver
The second piece of hardware is the receiver. It requests output from the transmitter and publishes is to whatever destination.
Here are some pictures showing the receiver in practice.
In the folder hardware/receiver you'll find the hardware design as a KiCad project. Without Kicad installed, you can view
- the schematic diagram as .pdf;
- the copper layout of the printed circuit board;
- the component placement on the printed circuit board.
About the receiver hardware:
- the RS232 level converter is the same as used for the transmitter, this time it is powered from 3V3;
- the character-based LCD screen to connect is a 2 rows of 16 columns type, using an HD44780 driver, connected via I2C @ 3V3, but powered @ 5V;
- the processor board (chosen because of its WiFi connectivity) is a ESP32 DevKitC (with ESP32-WROOM-32D module).
The folder software/WaterLevelReceivers is contains a set of Arduino sketches, each containing a different software solution for the receiver part of the project.
Read more about this piece of software here.
Connecting the transmitter with the receiver
| Transmitter | Receiver |
|---|---|
| GND (J1.2) | GND (J1.3) |
| TXD (J1.4) | RXD (J1.2) |
| RXD (J1.5) | TXD (J1.1) |
Lessons learned
Parts
23| Qty | Value | Footprint | References |
|---|---|---|---|
| 8 | 100n | Capacitor_THT:C_Rect_L7.0mm_W2.0mm_P5.00mm | C2, C3, C5, C6, C7, C8, C9, C10 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3 | H1, H2, H3, H4 |
| 1 | 100u/25V | Capacitor_THT:CP_Radial_D8.0mm_P5.00mm | C1 |
| 1 | 10u/16V | Capacitor_THT:CP_Radial_D8.0mm_P5.00mm | C4 |
| 1 | 1N4001 | Diode_THT:D_DO-41_SOD81_P10.16mm_Horizontal | D1 |
| 1 | 1N4148 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D2 |
| 1 | Analog | MyFootprints:Socket_Strip_Arduino_1x15 | P6 |
| 1 | Digital | MyFootprints:Socket_Strip_Arduino_1x15 | P5 |
| 1 | JSN-SR04T-2.0 | MyFootprints:JSN-SR04T-2.0-Vertical | U3 |
| 1 | MAX3232 | Package_DIP:DIP-16_W7.62mm_LongPads | U4 |
| 1 | Screw_Terminal_01x05 | TerminalBlock_MetzConnect:TerminalBlock_MetzConnect_Type101_RT01605HBWC_1x05_P5.08mm_Horizontal | J1 |
| 1 | TMP36 | Package_TO_SOT_THT:TO-92L_Inline_Wide | U2 |
| 1 | uA7805 | Package_TO_SOT_THT:TO-220-3_Horizontal_TabDown | U1 |
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Questions
How big is the Transmitter PCB?
It measures 85.1 × 53.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Transmitter use?
23 parts, built around the MAX3232ID. 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 Transmitter KiCad files?
From the mvanbrab/water-level repository on GitHub, at the commit this page was made from: the board is hardware/transmitter/transmitter.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Transmitter design in my own project?
Its repository states no licence, so its author keeps all rights: ask mvanbrab before reusing the design.